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2004, 23 (S1): 0-0

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STATISTICAL DAMAGE CONSTITUTIVE MODEL FOR SATURATED AND UNSATURATED ROCK

Wei Lide1，Xu Weiya2，Yang Chunhe1

2004, 23 (S1): 4285-4291

[PDF] 1633 KB (13)

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Based on probability statistics and damage mechanics，the characteristics of failure and damage of rock are studied，and the statistical damage constitutive model of rock is developed. For stresses，only effective stresses are employed in the damage evolvement function. The residual strength property of rock can be considered in the model. Then the statistical damage constitutive model is developed for saturated and unsaturated rock based on the mixture theory. The model can reflect the segment of concave in the stress-strain curve at the initial loading phase in the uniaxial compression test of rock，and the influence of damage in compression process and fluid in the pores or void on the stress-stain curves. The presented model is verified to be reasonable and practical in comparison with the experiment data.

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CHARACTERISTICS OF POST-PEAK DEFORMATIONS OF ROCK IN UNIAXIAL COMPRESSION BASED ON GRADIENT-DEPENDENT PLASTICITY

Wang Xuebin

2004, 23 (S1): 4292-4295

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Analytical solutions of axial，lateral，circumferential and volumetric strains，and post-peak Poissons ratio of rock specimen subjected to shear failure in uniaxial compression are proposed. Hookes law is adopted to describe elastic strain. Plastic strain is determined by gradient-dependent plasticity where internal length controls the thickness of shear band. Axial stress-axial strain curve，axial stress-lateral strain curve，axial stress-volumetric strain curve and axial strain-volumetric strain curve exhibit bi-linear behaviors due to the fact that constitutive relations of linear elasticity and linear softening are utilized. However，in the strain-softening stage，the curve of axial stress and post-peak Poissons ratio is nonlinear. Different from the Poissons ratio prior to the onset of shear strain localization，the post-peak Poissons ratio changes with axial stress levels and is possibly greater than 0.5. The volumetric strain measured in experiments or calculated by the present theoretical analysis depends on axial and lateral strains，which is related to the geometrical dimensions of rock specimens. Therefore，the slope of the axial stress-volumetric strain curve in strain-softening stage cannot be taken as a constitutive parameter，which is different from that of the axial stress-pure volumetric strain curve. The pure volumetric strain is the sum of elastic volumetric strain and plastic volumetric strain that is assumed to be due to shear dilatancy in shear band. The advantage of the present mechanical model is that the whole characteristics of deformations including post-peak Poisson’s ratio，axial，lateral，circumferential and volumetric strains can be described analytically by it.

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STRUCTURAL MECHANICAL ANALYSIS ON ROCK ELEMENT WITH OVAL JOINT Under compression

Yuan Lei，Wang Cheng

2004, 23 (S1): 4296-4299

[PDF] 728 KB (10)

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The mechanical calculation of multi-joint rock masses is one of the most difficult problems of rock mechanics. This problem is reduced into a rock element with an oval joint under compression，and then it is analyzed by structural mechanics. The stress distributions at key points in the element are obtained.

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RESEARCH ON RELATION OF D-P FAILURE CRITERION AND ROCK FRACTURE TOUGHNESS KIc，KIIc

Liu Jie，Li Jianlin，Zhou Jifang，Chen Pingshan，Chen Xinzhou

2004, 23 (S1): 4300-4302

[PDF] 635 KB (14)

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Through overlapping the stresses at the end region of a crack，the total stress at the end region of tensile and shearing crack is obtained，which is then introduced into D-P failure criterion. The relation between coefficient of D-P failure criterion and rock fracture toughness KIc，KIIc is deduced. The validity of deduced relation is proved by an example of slope rock masses in Three Gorges Project.

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CALCULATION OF ROCK RESISTANT FACTOR IN TUNNEL CONSIDERING INTERMEDIATE PRINCIPAL STRESS EFFECT

Xu Shuanqiang1，2，Yu Maohong1

2004, 23 (S1): 4303-4305

[PDF] 300 KB (10)

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Based on the unified strength theory，the formula for calculating rock resistant factor in circular hydraulic tunnel is derived. This formula can give some results obtained by previous formulas，and a series of new results which can consider the intermediate principal stress effect. Therefore，it can be applied to more situations of rocks.

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RESEARCH ON SOME PROBLEMS ABOUT gravity STRESS OF Rock or soil FOUNDATION

Lu Tianqi1，Lu Huiqing2，Yang Jianhua2，Liu Guangting1

2004, 23 (S1): 4306-4310

[PDF] 424 KB (21)

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Based on the analyses of relations of physical and mechanical behavior indexes of rocks or soils，such as the variation of bulk density，natural void ratio and consolidation settlement along with depth or gravity stress，the laws of deadweight stress field of rock and soil are discussed. The bearing capacity of foundation of soft glutenite and the favorable effect of gravity stress on the bearing capacity are analyzed by using field loading test in a hydraulic project and Hoek-Brown strength criterion. The results show that distribution of gravity stress is complex，and tectonic stress field exists in shallow layers of the earth crust.

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DETERMINATION OF ULTIMATE BEARING CAPACITY OF ROCK FOUNDATION BASED ON UNIFIED STRENGTH THEORY

Li Hangzhou1，Liao Hongjian1，2，Lan Xia1

2004, 23 (S1): 4311-4314

[PDF] 317 KB (19)

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The formulas of bearing capacity of rock foundation are established in conditions that the problem of bearing capacity of rock foundation is taken as the spatial problem and the intermediate principal stress is considered based on unified strength theory. When influence coefficient of intermediate principal shear stress b = 0，the formulas are the same as those by Mohr-Coulomb theory. The effect of b on bearing pressure is discussed，and the results show that the bearing capacity of rock changes with b.

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Earth Pressure Theory Based on Unified Strength Theory under plane strain state

Ying Jie1，Liao Hongjian1，2，Pu Wuchuan1

2004, 23 (S1): 4315-4318

[PDF] 565 KB (27)

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Based on the unified strength theory，the ultimate equilibrium stress equation under plane strain state is deduced and introduced into the Rankine earth pressure theory. Then the coefficients of active and passive earth pressure and the calculation formulas of earth pressure based on the unified strength theory are proposed. It is shown that the formula of Rankine earth pressure based on the Mohr-Coulomb strength theory is a particular case of the presented formulas. The earth pressure along the depth in a practical project is calculated with different weight coefficients which reflect the influence of intermediate principal stress，and the results prove that calculation results of earth pressure considering intermediate principal stress are closer to the practical situation than those without considering intermediate principal stress.

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RESEARCH PROGRESS IN NATURAL ELEMENT METHOD

Lu Bo1，Ge Xiurun1，Cheng Yonghui2

2004, 23 (S1): 4319-4324

[PDF] 592 KB (11)

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The natural element method (NEM) is a newly appeared numerical method to solve the partial differential equation (PDE). In the natural element method，the trial and test function are constructed using the natural neighbor interpolation method and the interpolation is constructed with respect to the Voronoi tessellation of the scattered points in the problem domain. The computation of the NEM shape function and its derivatives are relatively trivial. Because the matrix operation and inverse operation are not involved，the computation cost is small in contrast to common meshless methods. The NEM shape function satisfies the property of Delta function and the linear interpolation property is observed，so the essential boundary conditions can be exactly imposed，and the discontinuity in the field and its derivatives can be treated easily，which are troublesome in common meshless methods. Considering the construction and the properties of its shape function，the natural element method possesses the characteristics of meshless method and the advantages of finite element method，so it is the most promising numerical method and can be viewed as a midpoint between meshless method and finite element method. The solving process and the new research progresses are addressed. Some problems to be solved in the present NEM are pointed out and relating schemes are presented. Future development of this method and their applications are discussed.

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3D NUMERICAL ANALYSIS ON COMBINED ACTION OF ARCH ABUTMENT AND SLOPE GROUND WITH JOINTS IN THREE GORGES RESERVOIR AREA

Wang Cheng，Peng Nian

2004, 23 (S1): 4325-4328

[PDF] 402 KB (13)

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The properties of joint faces in bedrocks are one of the main factors of bearing capacity of bedrocks. 3D finite element models of the combined action of the arch abutment and the foundation with one，two and three joint faces respectively for the Three Gorges Reservoir Area are established. The analysis provides a basis for the research of the bearing capacity of bedrocks in the reservoir area.

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FINITE ELEMENT MODELING OF BACK ANALYSIS OF PERMEABILITY coefficient OF A TAILING DAM BASED ON BORING DATA

Li Kanghong1，Deng Xianghui1，He Meng1，Chai Junrui1，2，3，Li Shouyi1

2004, 23 (S1): 4329-4332

[PDF] 1205 KB (18)

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According to the present situation of a tailing dam，it is necessary to redesign the tailing dam to enlarge its volume and raise its final maximum elevation from 802 m to 860 m. So，the engineering geology and hydrogeology investigations are carried out to obtain the boring data and provide a basis for the design. The 3D finite element model of the whole dam area for back analysis of permeability coefficients is established based on the boring data and the results of the engineering geology and hydrogeology investigations. It is shown that it is feasible and effective to determine the permeability coefficients and solve the engineering problem by the back analysis of finite element model based on the boring data.

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ANALYSIS oN influence of tunnel EXCAVATION ON deformation of surrouding soil IN LOESSIAL strata

Zhang Xinshan，Liao Hongjian，Zhang Li

2004, 23 (S1): 4333-4338

[PDF] 585 KB (12)

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The numerical analysis on influence of tunnel excavation on the deformation of surrounding soil in loessial strata is performed based on loessial mechanics parameters of Xian Metro Line No. 1 by using the numerical analysis software，FLAC3D. The computation model of the tunnel is established based on the actual loessial field conditions. The regularities of the deformation of inner ground surface，vault and sidewall of the tunnel and the settlement of ground buildings in the earlier and later stages of tunnel excavation are studied.

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APPLICATION OF comprehensive FUZZY EVALUATion MODEL IN FROST HEAVING FORECAST

Xu Kun，Yang Gengshe

2004, 23 (S1): 4339-4342

[PDF] 483 KB (14)

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In the traditional fuzzy evaluation model，the weights of indexes are determined by subjective or objective method alone. A comprehensive fuzzy evaluation model is proposed to forecast frost heaving. In the model，weights of indexes are determined by combinative method，which makes the model more realistic and more effective. The model is proved to be reasonable and feasible by comparing the calculation value and the test value of an example.

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RANDOM-FUZZY ANALYSIS ON cohesion c and internal friction angle OF SOILS

Ma Junping1，Shan Renliang2，Han Youqiang2，Xu Haibo2

2004, 23 (S1): 4343-4346

[PDF] 315 KB (13)

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The parameters c and of the soil shear strength are calculated with the random-fuzzy analysis method in which the fuzziness of soil sample parameters is considered. The results show that the variability of numeral characteristic index calculated is small. Fitting tests show that the random-fuzzy values of parameters can be used in the analysis of engineering reliability，because fitting degree is high around the real value and the distribution form of collectivity is not changed

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PREDICTION OF MAXIMUM DRY DENSITY OF HETEROGENEOUS SOIL-rock mixture By ARTIFICIAL NEURAL NETWORK METHOD

Yu Linping1，Li Shengde2，Gao Chao1，Yang Jiuhong3

2004, 23 (S1): 4347-4350

[PDF] 315 KB (13)

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By using BP artificial neural network model and data of compaction tests，a new way for predicting the maximum dry density of heterogeneous soil-rock mixture and assessing the compaction properties of it is established. The results show that the method is accurate and effective.

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TESTS ON dynamic behavior OF FLY ASH DAM

Chen Jianbin1，Zhou Liyun2

2004, 23 (S1): 4351-4355

[PDF] 1589 KB (13)

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Based on the case of the fly ash dam of Leiyang Power Station in Hunan Province，the dynamic behavior of the fly ash dam at the elevations of 170，180 or 230 m with submerged beach or non-submerged beach is studied by models on the large-scale vibration table. The evaluation of earthquake-resistant behavior is also made on the models of 180 m fly ash dams heightened by three mixtures，and it is shown that the mixture type has little influence on the earthquake-resistant behavior of the dam. The tests show that the natural frequency of dam and the acceleration amplification ratio at the top of dam decrease with the increase of excitation acceleration and dam height and are lower under the condition of submerged beach than those of non-submerged beach.

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FEM ANALYSIS ON EARTH PRESSURE OF EMBEDDED CULVERT IN subgrade OR dike

Deng Guohua，Shao Shengjun

2004, 23 (S1): 4356-4360

[PDF] 445 KB (15)

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The previous calculations of the vertical earth pressure of culverts in road subgrade or dike projects are often not accurate enough，which lead to inaccuracy in structure design and engineering problem. Aiming at this problem，FEM is adopted to analyze the earth pressure of embedded culvert. It shows that the coefficient of vertical earth pressure gradually increases to a stable value with the increasing of the filling height，and that when the modulus of soils on the two sides is heterogeneous，the uneven deformation leads to the increase of vertical earth pressure. Based on the parameters of the ideal elastoplastic model which are calculated with the testing compression modulus of filling soils under various compaction degree，the coefficient of vertical earth pressure is determined，which agrees well with the earth pressure by in-situ testing. Because there is difference between settlement of the filling and the culvert，the range of coefficient of vertical soil pressure is about 1.2～1.35.

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RESEARCH Review on SUPERSTRUCTURE-PILE-SOIL INTERACTION

Xu Meijuan，Zai Jinmin，Mei Guoxiong

2004, 23 (S1): 4361-4365

[PDF] 332 KB (11)

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The research on pile-soil interaction is summarized. Developing process of research in this field，and calculation of bearing capacity and settlement are emphatically described. The future tasks are also put forward.

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ANALYSIS OF REINFORCEMETN-SOIL Interface FRICTION OF road embankment with geotextile

Zhou Jianping

2004, 23 (S1): 4366-4367

[PDF] 288 KB (12)

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Based on the results of FEM analysis of a great number of engineering cases of road embankments with reinforcement earth and geotextile，a modified distribution model of reinforcement-soil interface friction is proposed.

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ANALYSIS ON CHARACTERISTICS OF THERMO-VISCOELASTO RHEOLOGY OF BEISHAN GRANITE

Deng Guangzhe1，Wang Guangdi2

2004, 23 (S1): 4368-4372

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The rheologic characteristics of Beishan granite from Ganshu Province under temperature effect are analyzed with thermo-viscoelastic rheological model for rock. The numerical values of model parameters under different temperature are presented and the variation laws of them along with temperature are gained. Creep parameters (including creep compliance，influencing factors of time and temperature to creep，delay time of creep) and relaxation parameters (including relaxation modulus，influencing factor of temperature to relaxation，relaxation time) are analyzed and variation laws with temperature are acquired. Some conclusions are provided for the design of storeroom for nuclear waste.

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STUDY ON liquid-thermal-STRESS Coupling OF FREEZING-THAWING DAMAGE of SOFT ROCK

Ma Jingrong，Yang Gengshe

2004, 23 (S1): 4373-4377

[PDF] 359 KB (12)

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Freezing-thawing environment affects the stability of soft rocks in cold region. Because soft rocks have low strength and high porosity and contain large amount of expansive clay minerals，the freezing-thawing process of soft rock is complicated. Based on physical properties of soft rock and water-rock interaction and theories on continuum medium，heat conduction and mass transfer，basic equations of freezing-thawing process are established. The equations consider water movement，heat conduct，phase change of water and relevant latent heat. The FEM software，ANSYS，is employed to simulate the temperature distribution of soft rock tunnel and temperature-stress field. Simulation results agree with the practice. Liquid-thermal-stress coupling models are set up，in which soft rocks is taken as 3D elasticity body and the damage of soft rocks is considered. The distribution of frost-heaving force is determined by analytical method，and the damage parameters and elastic moduli of soft rocks in different stages are determined by using the equation of rheological damage.

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model test STUDY on PILE FOUNDATION OF 110 kV TRANSMISSION LINE OF Qinghai—TIBET RAILWAY in FROZEN SOILs

Cheng Yongfeng1，Lu Xianlong1，Liu Huaqing1，Wang Renhe2

2004, 23 (S1): 4378-4382

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According to similarity theory，the principles and methods of the frozen model test for pile foundation of the 110 kV transmission line of Qinghai—Tibet Railway in frozen soils are determined. Then the freezing strength between frozen soils and piles，the bearing capacity of pile foundation and the frozen soil pressure on piles under the independent and combined actions of the uplifting，lowering and toppling loads are studied. The results indicate that the freezing strength between frozen soils and piles，the bearing capacity of pile foundation and the frozen soil pressure on piles will all dramatically decrease with the increase of temperature. So，temperature is the determinative factor of the bearing capacity of pile foundation. Some suggestions on the selection of foundation types and the design optimization of pile foundation of transmission line in frozen soils are proposed.

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FIELD TESTS ON MECHANICAL CHARICERISTICS OF PERMAFROST ALONG TIANSHAN SECTION OF HUANGJI 220 kV TRANSMISSION LINE

Lu Xianlong1，Cheng Yongfeng1，Fei Xiangze1，Man Guoming2，Guo Yongsheng2，Xu Bo2

2004, 23 (S1): 4383-4387

[PDF] 434 KB (11)

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The permafrost or seasonal frozen soils are undesirable engineering geologic condition and the frost heave and thawing settlement will influence the stability of foundations. The Huangji 220 kV transmission line passes Tianshan permafrost region of Xinjiang. The field shear test，the field thawing compression test and the field static loading test in this region are systematically described. All these field test results provide firsthand data about characteristics of the frozen soil ground in this region and a basis for optimizing the design.

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DEVELOPMENTS OF ruptures or SO-CALLED WATER FILMS IN SATURATED sand

Lu Xiaobing1，Wang Shuyun2，Cui Peng2

2004, 23 (S1): 4388-4391

[PDF] 551 KB (9)

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The mechanism of rupture or so-called water films in saturated sand is analyzed. It is shown that there will be no stable water films in the saturated sand if there exists no effective stress. Only when the seepage velocity always equals to zero，do there exist stable water films. The evolution of water films is compared with some experimental results.

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STUDY ON DAMAGE MECHANICAL PROPERTIES OF ORIGINAL EXPANSIVE SOILS IN PROCESS OF TRIAXIAL SHEARING

Lei Shengyou1，Xu Ying1，2

2004, 23 (S1): 4392-4395

[PDF] 436 KB (12)

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The CT scanning in triaxial shear test on original expansive soils is conducted. Combining images and data of the CT scanning with the stress-strain curve，it is found out that the shearing process of the samples is actually the development of interior fissure. Before deviatoric stress reaches the peak strength，the CT number increases and the variance of CT number decreases，which indicates that the density increases and the expansive soils become more homogenous. But，after the deviatoric stress exceeds the peak strength，things goes in opposite direction. The fissures develop from the center of the soil sample to the edge until they connect and form shearing faces. The relationship between mean of CT number and variance of CT number to axial deformation are parabolas.

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TESTING STUDY ON CBR VALUE OF IMPROVED EXPANSIVE SOILS

Wang Yanran，Cao Dingsheng

2004, 23 (S1): 4396-4399

[PDF] 831 KB (9)

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Based on the construction of Zhenshao highway，a series of indoor and outdoor tests are carried out to find out the major influencing factors of CBR value of improved expansive soils. The variation rule of CBR value and the methods of improving CBR value of roadbed of expansive soils are discussed.

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SITE SELECTION OF OBSERVATION STATION for EXPANSIVE SOILS IN RAINY AND hot AREAS

Lu Haibo1，2，Zhao Yanlin1，Luo Huilai1，Kong Lingwei2

2004, 23 (S1): 4400-4404

[PDF] 1003 KB (33)

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The engineering properties of expansive soils are sensitive to climatic changes. The distribution，engineering properties and local climate of expansive soils in Guangxi are summarized. Based on meteorologic factor and the results of a previous research project，site selection of observation station of expansive soils are carried out. The observation station provides a work platform for research on mechanism of engineering properties and climate changes.

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APLICATION AND ENGINEERING PROPERTIES OF RESIDUAL SOILS OF RED BEDS

Peng Baixing1，2，Wang Xinghua1

2004, 23 (S1): 4405-4408

[PDF] 343 KB (13)

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Residual soils of red beds in north Hunan Province exhibit special engineering geologic behaviors. There are many difficulties in the selection of mechanical indexes when they are used as supporting course. Based on analyses of measured data，the determination of bearing capacity and deformation characteristics of these soils acting as subgrade are discussed. The evaluation methods for the bearing capacity of this kind of foundation and deformation modulus are also suggested.

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testing study on mechanical characteristics of NATURAL underconsolidated soilS

Liu Yuanxue1，2，Jiang Shuping2，Zhao Yanming1

2004, 23 (S1): 4409-4413

[PDF] 570 KB (13)

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The mechanical characteristics of natural soils are significantly affected by their structure. The special mechanical characteristics of natural soils and the influence of stress path on natural soils are disclosed through the comparison of results of tests on natural soils and manipulated soils with multiple stress paths. The structural and underconsolidation behaviors of natural soils are shown in the normal consolidation experiment. The structure damage of the natural underconsolidated soils caused by the increment of volumetric strain is more significant than that caused by the increment of shearing strain. The influence of the structure on natural soils is mainly embodied as the increase of internal friction angle. At small strain，natural soils are of high stiffness，obvious nonlinearity and are markedly different from the manipulated soils. Through the comparison of test results of natural soil samples cut from different direction，the anisotropy of natural soils which becomes obvious as strain decreases is illustrated.

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ON SOIL PARAMETERS OF cone penetration test (CPT) IN COASTAL AREA OF FUJIAN

Jian Wenbin，Wu Zhengxiang，Liu Huiming，Chen Zhibo，Zhang Minxia

2004, 23 (S1): 4414-4417

[PDF] 688 KB (13)

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The soil parameters of cone penetration test (CPT) in the coastal area of Fujian Province are obtained. The soil classification charts are plotted using the CPT parameters of soft soil，clay and sandy soil. The charts can be used for fast soil classification in geotechnical investigation practice. Thus，results of this research can reduce workload for borehole surveying and the investigation time for construction projects in this area.

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STUDY ON DREDGED SOIL USED AS IMPERMEABLE MATERIALS OF CLAY LINER OF LANDFILL

Shi Chengjiang，Tang Xiaowu，Lin Tingsong

2004, 23 (S1): 4418-4421

[PDF] 472 KB (11)

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For the 3 key factors of clay liners of landfill，permeability，strength and absorptivity， geotechnical and geoenvironmental properties of the mixed soils (dredged soil and silty clay) are studied and compared with the original silty clay by series of laboratory tests. The results of laboratory tests show that the mixed soils can reduce permeability coefficient，increase strength and adsorption capacity to Cu2+ and Zn2+. Generally，the geotechnical and geoenvironmental properties of the mixed soils are much better than those of the original silty clay.

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FEASIBILITY STUDY ON SOIL IMPROVEMENT WITH COAL ASH

Li Shumin，Akaishi Masaru

2004, 23 (S1): 4422-4427

[PDF] 966 KB (23)

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The feasibility of coal ash used as soil improvement material is studied. To investigate the effect of coal ash on the compression and strength characteristics of improved weak soils，consolidation tests and triaxial compression tests are carried out with soil samples of various mixing ratio. The test results show that maximum dry density and shear strength increase and consolidation coefficient and secondary consolidation coefficient decrease with the increase of the percentage of coal ash.

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Study on parameters of constitutive model of materials of a high embankment dam

Zhang Ru，He Changrong，Fei Wenping，Chen Qun

2004, 23 (S1): 4428-4434

[PDF] 922 KB (10)

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Systematical testing studies on 8 kinds of materials for a high embankment dam whose maximum height is 258 m are performed. Stress-strain-strength characteristics of them in high stress conditions are analyzed through large triaxial tests. The results show that cohesion c of embankment materials does exist，which contradicts the routine idea c = 0. The value of c is suggested for this project. And the results show that shear strength characteristics are obviously nonlinear and deformation properties are harmonious. According to original physical meaning of Duncan-Chang model，an improved method for determining strength parameters is introduced，which involves a and b. Different figures are drawn in different axis strains a，and a or initial modulus Ei is obtained according to the possible minimum value of a，whereas b is gained from a bigger range of a. Since basic physical meaning of a and b are thoroughly different，the improved method overcomes the defect of routine method which obtains the two parameters on the same line. According to different coordinate scales，different parameters including a and b，and corresponding Ei，k，n and Rf of Duncan-Chang model are gained. Suggested parameters are proposed in comparison with constitutive parameters by routine method and they are proved to be reliable by data fitting.

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STUDY ON RELATIONSHIP of SHEAR WAVE VELOCITY AND SHEAR STRENGTH OF FOUNDATION

Xia Tangdai1，Yan Kezhen1，Shi Zhongming2，Xue Yuedong3

2004, 23 (S1): 4435-4437

[PDF] 348 KB (30)

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The shear strength is an important index of mechanical properties regarding to stability and safety of structure. The relationship formula of shear strength of soft clay and shear wave velocity is derived according to the nonlinear constitutive relationship of soil，Mohr-Coulomb strength theory and soil dynamics theory. Comparison of the results of shear strength by field measurement and the relationship formula shows that the relationship formula is effective to calculate shear strength of soil by shear velocity. So a quick，economical and nondestructive testing method for determining shear strength is developed.

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Testing study on transient STRESSES IN SOIL NAILS

Yu Xiaojin1，Zeng Xianming1，2，Chen Mengcheng1

2004, 23 (S1): 4438-4441

[PDF] 311 KB (12)

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The key elements and condition of the field test on performance of soil nails against dynamic load in the loess carven are discribed，and test results of the testing soil nails at top of the cavern arch are given. The one-dimension viscoelastic Maxwell model is used in data fitting. The relations between the transient stresses in the testing soil nails and the burying depths of the unsupported cavern and the cavern with soil nails and structure measure under the action of blast-induced stress wave are compared. The relations between the relative stresses and the relative distance to explosion center of these caverns are also compared. The tests indicate that the cavern with soil nails and structure measure has better performance of dynamic viscoelasticity.

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APPLICATION OF PRESSUREMETER TESTS IN GEOTECHNICAL ENGINEERING

Shi Xiangfeng，Wang Ren，Zhang Jiaming，Huang Mingkui，Li Jianguo

2004, 23 (S1): 4442-4445

[PDF] 393 KB (46)

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The application of pressuremeter tests in the loess foundations，foundations of highrise building and bridge is introduced and some problems of the tests are analyzed.

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STUDY AND APPLICATION OF electrical-logging VANE SHEAR TEST

Li Hongzeng

2004, 23 (S1): 4446-4449

[PDF] 513 KB (14)

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Because vane shear test can obviously improve the veracity of the mechanical indexes for saturated soft clay，it is applicable to coastal area with soft soils and in calculation the important mechanical parameters of foundation such as the bearing capacity of foundation and the sensitivity of soft clay. Based on the test principles and calibrating method of electrical-logging vane shear test and construction experiences of soft soil foundation in Dongying coastal area in Shandong Province，the relational expressions of parameters of vane shear test in this area are put forward.

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EXPLICIT SOLUTION of acceleration factor FOR GENERAL SLICE METHOD

Yang Mingcheng

2004, 23 (S1): 4450-4455

[PDF] 512 KB (14)

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For the solution of acceleration factor in slope stability analysis，the normal force of the slice base is directly assumed based on the equation of the normal force of the slice base，which makes the calculation of the normal force of slice base have two factors to be determined. Compared with the traditional inter-slice force assumption，the proposed assumption is more sufficient in theoretical foundation and clearer in physical meaning. By simplifying the three global limit equilibrium equations (horizontal force equilibrium equation，vertical force equilibrium equation and moment equilibrium equation) for potential slide mass by the assumed normal force of slice base，a linear equation of the acceleration factor is derived，the root of which is the explicit solution of the acceleration factor for general slice method and rigorously satisfies the global equilibrium conditions for potential slide mass. Although there are more parameters involves in the computation，the computation is simple algebraic summation and the computation precision is satisfying. The presented method greatly simplifies the calculation process of the acceleration factor for general slice method with rigorous framework. On this basis，a methodology to solve the safety factor is established. The example analysis indicates that the proposed explicit solution to the acceleration factor for general slice method is correct and the proposed method is reasonable and effective.

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global SEARCH METHOD IN SLOPE STABILITY ANALYSIS

Lu Wenjie，Zhu Hehua，Li Xiaojun

2004, 23 (S1): 4456-4459

[PDF] 336 KB (14)

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The main characteristics of Tongji Shuguang slope stability analysis software are introduced generally. Aiming at the problem of broken arcs existing in many kinds of software of slope stability analysis，a set of integrated optimization model is put forward. The model has higher convergence rate，and better logicality and integrity. Finally，the feasibility of the model is proved by two examples.

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DISTRIBUTION OF PASSIVE EARTH PRESSURE WITH RIGID retaining WALL ROTATING ABOUT WALL TOP

Kong Liang，Zhang Jiquan

2004, 23 (S1): 4460-4462

[PDF] 427 KB (19)

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Based on the condition of static equilibrium in the sliding soil，the expression of passive earth pressure with rigid retaining wall rotating around wall top (RT) for cohesionless soils is established. The comparisons are made among the presented formula，the Coulomb formula and some experimental observations. It is demonstrated that the presented formula can well reflect the nonlinear distribution of passive earth pressure. The magnitude of the resultant earth pressures for the movement mode of RT of rigid retaining wall is approximately equal to that by the Coulomb theory，and the action points of the resultant earth pressures lie around 0.27 times of the height of rigid retaining wall.

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FINITE ELEMENT ANALYSIS ON SLOPE STABILITY with THEORIES OF LARGE ELASToPLASTIC DOFORMATION AND STRENGTH REDUCTION

Zhang Shibing，Wang Lianzhu，Zhang Jian

2004, 23 (S1): 4463-4467

[PDF] 730 KB (11)

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The constitutive equations and FEM formulations of rock masses of large elastoplastic deformation are established by using updated Lagrangian method. The strength reduction method is employed in slope stability analysis. Strength parameters are divided by an increasing factor until the plastic zone forms a sliding surface and the computation program can not converge. Then the safety factors are determined. The results show the reduce of strength parameters of soils induced by rainfall is the major factor leading to instability of the slope，and the increase of the weight of slope body is secondary factor.

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ANALYSIS ON DEFORMATION AND FAILURE MECHANISM OF HIGH ANTIDIP SANDWICH ROCK SLOPE IN EXCAVATION

Leng Xianlun1，Sheng Qian2，Liao Hongjian1，2，Xiong Jun2，Guo Zhihua2

2004, 23 (S1): 4468-4472

[PDF] 494 KB (12)

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Based on the generalized analysis of the geological conditions，test of rock mass stress and deformation monitoring of the test tunnel in the Longtan Project，the simplified geological model and the excavation model of the high antidip sandwich rock slope are set up. Based on the testing data of stress，initial stress is assumed to distribute linearly. The 2D explicit finite difference method is used to simulate the equilibrium with gravity and excavation process of section 1-1 of the slope of left-bank intake. By analysis，the relationship among development of critical joint，joint separation scale and deformation in high rock slopes is obtained. Comparison of flats of 480，313 m shows that excavation has great influence on critical joint and excavation will lead to development of critical joint and increase of joint separation scale. It is objective to estimate stability and possible failure form of slope by discrete element code，UDEC2D3.1.

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STABILITY ANALYSIS ON consequent ROCK CUTTING SLOPE by FINITE ELEMENT METHOD

Li Lianghui1，Yu Fei1，Wang Ping1，Gong Wenhui1，Wang Yuanhan1，2

2004, 23 (S1): 4473-4477

[PDF] 492 KB (15)

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Stability analysis of cutting slopes is an important issue in road construction. The nonlinear finite element analysis of a consequent rock cutting slope is carried out based on the engineering geology investigation. The excavation deformation of the consequent rock cutting slope is simulated by using the strength-reduction theory and ANSYS. The mechanism and evolution process of failure are analyzed. Some reasonable suggestions are put forward for the treatment of slopes.

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STABILITY ANALYSIS OF EXPANSIVE SOIL SLOPE WITH RAINFALL INFILTRATION

Ping Yang1，Liu Mingzhi1，Zheng Shaohe2

2004, 23 (S1): 4478-4484

[PDF] 2431 KB (13)

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Considering the cracking of expansive soils，seepage characteristics of expansive soil slope are studied under circumstance of rainfall infiltration. Numerical analyses on slope stability are conducted accordingly. Simulation results show that there are obvious differences between numerical simulations with and without considering cracks in expansive soils. The field tests and numerical analyses show that it is essential to include the crack condition in the stability analysis of expansive soil slope with rainfall infiltration.

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STUDY ON APPLICABILTY of ZHAOSHULING PALEO-LANDSLIDE AREA As building siteS

Wu Yiping1，2，Liu Yourong2，Tang Huiming2

2004, 23 (S1): 4485-4488

[PDF] 858 KB (13)

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Based on the analysis of the geological environment and deformation-failure condition of Zhaoshuling paleo-landslide area in Three Gorges Area，the stability of the paleo-landslide after the Three Gorges Reservoir is impounded is evaluated. Combined with stability evaluation，the relative matter-element model is set up to evaluate the site applicability of the interest area. The interest area is divided into three grades. The result provides a basis for the reasonable exploitation of the area in the future.

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FEM STABILITY ANALYSIS on SLOPEs reinforced by PRESTRESSED ANCHOR CABLE

Xia Xiong1，2，Zhou Depei2，Xiao Shiguo2

2004, 23 (S1): 4489-4492

[PDF] 474 KB (24)

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A stability analysis method of nonlinear finite element method for slopes is established. The results of this method can provide a systematic description of the whole state，including deformation behaviors，extension of plastic zone，and formation and evolution of slip surface in slopes. After the location of the slip surface is determined，the limit equilibrium method is used to calculate the safety factors of slope and evaluate the slope stability. An example shows that this method established here is reasonable and effective.

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3D NUMERICAL SIMULATION OF THE HIGH CUT SLOPE OF TIANWAN NUCLEAR POWER PLANT

Li Tonglu1，2，Fan Wen1，2，Li Ping1，2

2004, 23 (S1): 4493-4497

[PDF] 837 KB (19)

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The mechanical parameters of rock masses are controlled by rock and structural planes，the determination of which is one key issue in numerical simulation of rock engineering. In the case of the high cut slope of Tianwan Nuclear Power Plant，mechanical parameters of rock are obtained by laboratory tests，and parameters of structural planes by field investigations. Considering the structural planes as initial damage，damage mechanics is applied to analyze the deformation parameters of rock masses by discounting mechanical parameters of rock. Meanwhile，RMR classification and the Hoek-Brown criterion are employed to estimate the strength parameters of rock masses. Three excavation schemes of the high cut slope are simulated by this methodology with the data of field and laboratory investigations，and a reasonable scheme is proposed consequently.

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STABILITY ANALYSIS ON REINFORCEMENT DESIGN OF YANZIYA HIGH SLOPE OF DANGEROUS ROCK MASSES

Gu Shuancheng，Zou Renhua

2004, 23 (S1): 4498-4501

[PDF] 563 KB (16)

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According to the effect of cracks and ground water in small openings of the Yanziya high slope of dangerous rock masses，ANSYS is used to analyze the stability of the dangerous rock masses before and after reinforcement. The results provide theoretical basis for the reinforcement design and stability evaluation of the high dangerous rock masses.

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ANALYSIS ON STABILITY INFLUENCING FACTOR OF ZITONGMIAO LANDSLIDE IN WULONG，CHONGQING

Tang Qiuyuan

2004, 23 (S1): 4502-4505

[PDF] 535 KB (23)

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Through qualitative and quantitative analyses on influencing factors of landslide stability，formation mechanism of landslides is studied. The results provide a basis for the design and execution of mitigation projects.

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BACK ANALYSIS ON macromechanics PARAMETERS OF rock masses of the SLOPE OF GEHEYAN hydraulic power station

Zhou Jifang，Li Jianlin，Liu Jie，Yang Xuetang

2004, 23 (S1): 4506-4508

[PDF] 430 KB (10)

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Based on the characteristics of the slope of Geheyan hydraulic power station，the simulation models are constructed for the rock masses in the zone of decisive influence. The mechanical parameters of unloaded rock masses are adopted in the back analysis with the large-scale FEA software，ADINA. The macromechanics parameters and the degradation law of these parameters are obtained.

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STABILITY ANALYSIS OF 5# LANDSLIDE OF SHANGSAN HIGHWAY

Chen Yunfa1，Xu Jiancong2，Yu Boting2，Lu Qing2

2004, 23 (S1): 4509-4512

[PDF] 865 KB (12)

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With three different profiles，stability of 5# landslide of Shangsan highway is analyzed. The result reveals that the contact part between quaternary loose accumulative formation and weathered zone of bedrock often becomes the potential sliding surface in road bed of thick loose soils，and rainfall will reduce the stability factor. And treatment schemes of prestressed anchor cables are proposed for unstable sections.

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Landslide Hazards and Their Prevention and mitigation at Minhou—Minqing section of 316 National Highway

Wu Maoming1，2，Jian Wenbin1，2，Wu Zhenxiang1，2

2004, 23 (S1): 4513-4516

[PDF] 351 KB (25)

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Based on site investigation and laboratory experiments，the primary geologic disasters，landslides and dangerous rocks at the Minhou—Minqing section of 316 national highway in Fujian Province are discussed. Based on analyses on the geologic environment，formation mechanism and influencing factors of the stability of slope are determined by Sweden method. Countermeasures，including draining，load reducing，anchoring and retaining wall，are proposed.

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MECHANISM ANALYSIS OF LANDSLIDE INDUCED BY ACCUMULATION LOADING OF HIGHWAY

Dong Fuqian1，Miu Zhishun1，Lu Qing2，Xu Jiancong2

2004, 23 (S1): 4517-4520

[PDF] 1202 KB (21)

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Based on geological exploratory profile of 1# landslide in Shangsan highway，numerical analysis model is established. The characteristic of deformation and failure of slope under accumulation loading is studied by using contact model of elastic-plastic material. The mechanical mechanism of occurrence and development of deformation and failure of slope is revealed. The research results show that accumulation loading on slope of loose accumulation mass directly changes slope stability and seepage condition of groundwater，and reduces stability of slope mass，which finally leads to occurrence of landslide.

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APPLICATION OF CEDAR PILES IN TREATMENT OF LANDSLIDE

Peng Dingxin

2004, 23 (S1): 4521-4524

[PDF] 799 KB (10)

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For the landslide of Wuli Dam of Yangtze River in Jiangxia District，Wuhan City，factors leading to sliding are analyzed and the treatment scheme is determined by comparing different schemes. Cedar piles are chosen as anti-slide piles. The action mechanism of cedar piles is analyzed and the optimum design is proposed. The treatment result shows that cedar piles are effective in the urgent，temporary or special treatment of landslides. This technique possesses many advantages，such as low cost，quick installation and easy operation.

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SOIL MOULD METHOD OF FLYOVER CONSTRUCTION IN EXCAVATION SECTION OF HIGHWAY

Zhou Wei，Liu Yalin

2004, 23 (S1): 4525-4527

[PDF] 272 KB (12)

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Based on a practical case，the soil mould method of flyover construction in the excavation section of highway is introduced and analyzed.

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dilatancy theory for identification of PREMONITORY INFORMATION of ROCK BURST

Pan Liyou1，2，Yang Huizhu1

2004, 23 (S1): 4528-4530

[PDF] 533 KB (11)

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Based on the experiments and the numerical simulations of the fracture and instability of impact coal mass，the deformation and break of coal mass are divided into 3 stages，namely，elastic stage，nonlinear stage and mutation stage. The dilatation process of coal mass is depicted by 3 characteristic quantities，namely，volume compression，steady dilatation and dilatation mutation. The dilatation model of rock burst is established. Dilatancy theory explains the stability and mutation of premonitory information of rock burst. It is the theoretical basis for identification of premonitory information of rock burst. The software RFPA is used to validate the relation between dilatation mutation and premonitory information of acoustic emission.

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NUMERICAL ANALYSIS ON MOVEMENT AND FAILURE of coal AND stress condition OF SUPPORT structures in MECHANIZED TOP-COAL CAVING IN STEEP THICK SEAM

Wang Shuren，Wang Jinan，Dai Yong

2004, 23 (S1): 4531-4534

[PDF] 528 KB (10)

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The rules of coal and rock movement，the characteristics of deformation and failure of coal，and the major principal stress in the process of top-coal caving in steep thick seam are analyzed by using UDEC2D. The characteristics of stress and movement of support structure at top-coal caving face are investigated by using FLAC3D. The simulation results agree with the field conditions.

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RESEARCH ADVANCES IN SURFACE AND ROCK-MASS MOVEMENT

Mei Songhua1，2 Sheng Qian1，Li Wenxiu2

2004, 23 (S1): 4535-4538

[PDF] 718 KB (16)

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The methods for the prediction of surface and rock-mass movement are summarized from the aspects of theoretical and experimental research and classified into four types，namely，fitting method，continuous mechanics method，numerical method and physical simulation method. Some current focuses in the research field of surface and rock-mass movement，including mining subsidence in the tectonic stress and other especial conditions，back-analysis of ground movement parameters，unification of time and space in rock-mass movement，are discussed. Some suggestions about engineering application，numerical method and constitutive models of surface and rock-mass movement are then proposed.

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MONITORING AND ANALYSIS ON DEFORMATION OF DEEP SOILS DURING SHIELD TUNNELING

Li Dayong1，Chen Fuquan2，Wang Hui3

2004, 23 (S1): 4540-4543

[PDF] 1288 KB (18)

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Shield tunneling may cause not only the soil settlement，but also the longitudinal and transversal displacements in the respect to direction of shield advancing. The latter ones may have destructive effect on nearby buildings and buried pipelines. Monitoring is carried out for displacement of deep soils. The results show that the displacements of deep soils is related to the pose of shield，the pressure of the soil chamber，the depth of the tunnel and soil properties. The measures for restricting the displacements of deep soils are proposed accordingly.

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ENGINEERING GEOLOGICAL ANALYSES ON 2·22 BLOCKAGE ACCIDENT IN TBM CONSTRUCTION OF Shanggongshan Tunnel

Song Tiantian1，Xiao Zhengxue1，Su Huayou1，Lu Xiaoxia2

2004, 23 (S1): 4544-4546

[PDF] 461 KB (29)

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During the course of the TBM construction in Shanggongshan Tunnel，the TBM blockage occurs frequently. So the blockage has become the main control factor of the TBM construction. Base on the 2·22 blockage accident，engineering geological analyses are carried to search for the general rules of TBM blockage and countermeasures.

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STUDY ON EARTHQUAKE-INDUCED PERMANENT DEFORMATION AND DYNAMIC STABILITY OF HIGH concrete-faced rockfill dam

Zhao Jianming，Chang Yaping，Chen Ning

2004, 23 (S1): 4547-4552

[PDF] 1007 KB (24)

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Evaluation method of earthquake-induced permanent deformation and dynamic stability are proposed based on 3D nonlinear dynamic FEM for the high concrete-faced rockfill dam (CFRD) of Jishixia Hydroelectric Project in meizoseismal area of west China. Using the proposed method，seismic response of the dam，such as the earthquake-induced permanent deformation，element anti-seismic safety，and dynamic stability of concrete face and dam slope are studied.

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Study on Seismic response Characteristics of Grounds and Structures in west Liaoning Province

He Yong1，Iwatete Takahiro1，Oda Yosiya1，Che Ailan2

2004, 23 (S1): 4553-4557

[PDF] 1569 KB (7)

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In order to study the seismic response characteristics of grounds and structures in west Liaoning Province or Jinzhou City，microtremor observations are carried out at 75 points in the center area with span of 10 km×10 km. The feasibility in regional domain and soundness in time domain of microtremor observations in this area are confirmed. The predominant frequencies of the ground are evaluated by the Fourier spectra of each components (NS，EW and UD) and Fourier spectra ratio (NS/UD and EW/UD). The north of Jinzhou City shows a predominant frequency rang of 5～18Hz and the south of it shows a predominant frequency range of 2～4Hz. The shear velocity of the surface layers is about 180 m/s. Based on the case of the International Communication Center of Liaoning Institute of Technology，the seismic response of typical structures in Jinzhou City subjected to the Kobe earthquake response spectrum is analyzed.

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SUBSIDENCE OF BUCKET FOUNDATION UNDER HORIZONTAL DYNAMIC LOAD

Wang Yihua1，Lu Xiaobing1，Wang Shuyun1，Shi Zhongmin2

2004, 23 (S1): 4558-4561

[PDF] 873 KB (11)

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Physical model tests are carried out to study the responses of the bucket foundation under horizontal dynamic load. The subsidence of the bucket foundation and the uniform soil layers is investigated. It is shown that the soils around the bucket softens or even liquefies under the dynamic load. The strength of the soils degrades and the bucket sinks gradually.

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TESTING STUDY OF quality detection METHODS OF LOESS ROADBED TREATed WITH DYNAMICAL COMPACTION METHOD

Wang Jili1，Liu Yilin2，Luan Maotian1，Shen Xingfu3

2004, 23 (S1): 4562-4567

[PDF] 2554 KB (11)

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In-situ tests，such as loading tests and sounding tests，are performed in the test site of a expressway roadbed in the loess region before and after the treatment of dynamical compaction method (DCM) is carried out. The indoor geotechnical tests are also performed. The quality detection of roadbeds treated with DCM is conducted based on these tests. Some suggestions are proposed about the quality detection of roadbed treatment in loess region.

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ANALYSIS ON BEARING CAPACITY OF DIVING DRY-VIBRATION COMPACTION STONE PILES

Sun Ju，Liu Kaifu，Xie Xinyu，Zhu Xiangrong

2004, 23 (S1): 4568-4572

[PDF] 318 KB (24)

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Based on the practice of stone piles，the bearing capacity of composite foundation of stone piles is calculated using the formula recommended by the code and the modified Brauns theory. The calculation results are compared with those by in-situ tests. It is shown that the calculating results of these two theories are both consistent with the observations，and the bearing capacity calculated by using the modified Brauns theory is appreciably larger.

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Several issues in improvement of foundation of soft soils WITH dynamic drainage consolidation method

Zhang Jun，Yang Zhiyin

2004, 23 (S1): 4573-4575

[PDF] 293 KB (24)

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The mechanism，technology and application range of dynamic drainage consolidation method and dynamic consolidation method are compared. Based on analysis of engineering examples of dynamic drainage consolidation method which combines dynamic and static loads，the main factors of pore water pressure and critical fill depth in this method are presented. The effective improving depth and the method for determining optimum tamping energy are also given.

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APPRAISAL OF SANDY SOIL FOUNDATION OF LARGE OIL TANKS IMPROVED BY VIBRO-COMPACTION GRANULAR PILES

Shi Shangwei，Xie Xinyu，Ying Hongwei，Zhu Xiangrong

2004, 23 (S1): 4576-4580

[PDF] 1438 KB (11)

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Based on the treatment practices of sandy soil foundation with vibro-compaction granular piles for the large oil tanks of Maoming Petrochemical Company in Maoming City，Guangdong Province，some problems about the design of vibro-compaction granular piles are discussed. The characteristics of improved foundation are evaluated according to the in-situ testing results. It is shown that vibro-compaction granular piles can improve the bearing capacity of foundation，reduce the settlement and avoid the sand liquefaction. So they can be used to treat sandy soil foundation.

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SENSITIVITY ANALYSIS On average one-dimensional CONSOLIDATION degree OF DOUBLE-LAYERED SOIL foundation

Yang Hongpo，Xie Xinyu，Xie Kanghe

2004, 23 (S1): 4581-4585

[PDF] 652 KB (12)

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The sensitivity of the average one-dimensional consolidation degree of double-layered saturated soil foundation with vertical consolidation coefficient of Gamma distribution，logarithmic normal distribution and Beta distribution is studied by using the two-point probability estimation method. The influences of variability and distribution types of consolidation coefficient on the average one-dimensional consolidation degree are analyzed.

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APPLICATION OF MIXED METHOD IN CALCULATING FINAL SETTLEMENT OF rigid PILE-GROUP Foundation

Gao Qiang，Yang Longcai，Wang Binglong，Dong Yueying

2004, 23 (S1): 4586-4589

[PDF] 633 KB (12)

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By considering‘the effect of bar’between piles，the formula for calculating the pile deformation is used in this paper. The settlement of pile-group foundation is calculated with the equivalent pier method. The method for determining the compression modulus of soils for final settlement is discussed. An engineering example proves the feasibility of the mixed method.

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NUMERICAL ANALYSIS ON EFFECTS OF CUSHION OF COMPOSITE foundation WITH PILE GROUP

Qi Kejun，Zai Jinmin，Mei Guoxiong，Wang Xudong，Zhang Yunjun，Chang Yinsheng

2004, 23 (S1): 4590-4592

[PDF] 714 KB (10)

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According to the property of the composite foundation，the adjustment procedure between piles and soil and the functions of the cushion are analyzed. The effects of the cushion of the composite foundation with pile group are simulated by finite element method，and the stress ratio of piles and soils is computed with various thickness of the cushion.

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SETTLEMENT CALCULATION METHOD FOR EMBEDDED FOUNDATION RESTING ON ELASTIC SOIL

Mei Guoxiong1，2，3，Zai Jinmin1，Zhao Weibing1，2，Yin Jianhua3

2004, 23 (S1): 4593-4596

[PDF] 1113 KB (16)

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Five effects of embedment depth，namely，Gibson effect，trench effect，side-wall contact effect，retaining wall effect and floating foundation effect，are analyzed. A new settlement calculation method for embedded foundation resting on elastic soils is then presented. The reduction coefficients of effects of embedment depth are discussed and some valuable conclusions are presented for engineering practice.

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SAFETY FACTOR OF COMPOSITE PILE FOUNDATION DESIGNed BASED ON ULTIMATE BEARING CAPACITY OF SINGLE PILE

Zhang Yunjun1，Zai Jinmin1，Wang Xudong1，Wang Wei2，Qi Kejun1

2004, 23 (S1): 4597-4601

[PDF] 339 KB (28)

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Based on the mechanism of combined action of piles and soils in composite pile foundation，the safety factor of foundation is analyzed. By considering the influence of the load ratio and safety factors of piles and soils，the component factor method for defining the safety factor of total bearing capacity is presented. It’s suggested that the ultimate bearing capacity of soil will increase when the influence of caps is considered and the ultimate bearing capacity of pile will change because of pile group effect. So，the presented definition and calculation of the safety factors of foundation are more reasonable and integral than previous ones.

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GRAY SYSTEM ANALYSIS OF BEARING CAPACITY OF PILE foundation BASED ON EXPERIENCES

Xu Xinyue1，Chen Xianxin2

2004, 23 (S1): 4602-4605

[PDF] 324 KB (18)

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The bearing capacity of pile foundation is a dynamic system that varies with time and space and is affected by many factors and characterized by uncertainty and limited information data. Thus，the utilization of the existing experiential knowledge is very important in bearing capacity analysis. A new approach to bearing capacity analysis of pile foundation，using the existing experiential knowledge，is presented based on the theories of gray system and analogue. The examples show that the presented method is simple and practical.

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two-stage fuzzy comprehensive assessment OF supporting EFFECT OF DEEP FOUNDATION PITs

Liu Chun

2004, 23 (S1): 4606-4609

[PDF] 328 KB (13)

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The assessment criterion of supporting effect of deep foundation pits is complicated and fuzzy. Some major factors in assessment are proposed. Based on the neural network for assessment，two-stage fuzzy comprehensive assessment is employed to evaluate supporting effect. Case study shows that the method is simple and convenient and the assessment result is satisfying.

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analysis on driving process of STEEL PILEs by BACK ANALYSIS METHOD

Liu Run1，Yan Shuwang1，Yang Xiaogang2，Liu Yuan3

2004, 23 (S1): 4610-4614

[PDF] 466 KB (16)

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Reliable soil properties play an important role in predicting the drivability of steel piles. There is great discreteness in the investigation data of RDPP1 platform in Yangcheng Gas Field，which results in difficulty in predicting the pile drivability. Therefore，these data can not be directly used in the prediction and it is necessary to determine a set of reliable data. Based on the existing investigation data and the driving record of test piles，back analysis method is adopted in determining the soil properties. A set of soil data is determined and applied in the prediction by using the one-dimension wave equation and a computer program. The prediction results agree well with the observation，which shows the proposed back analysis procedure is reliable in similar projects.

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SEVERAL ISSUES ABOUT NEGATIVE SKIN FRICTION OF PILES

Chen Xianxin1，Xu Xinyue2

2004, 23 (S1): 4615-4618

[PDF] 444 KB (17)

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According to the mechanism of negative skin friction of piles，several issues encountered in soft soil area are discussed. Countermeasures against negative skin friction are proposed. The application of negative skin friction of pile foundation in the correction of building inclination is also introduced.

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combined application OF ground treatment and SUPPORT of foundation PITs in silts

Lai Zhengfa，Li Kaiwen，Dong Zhu，Yang Zhengdong

2004, 23 (S1): 4619-4622

[PDF] 786 KB (17)

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Based on the case of foundation pit of the sewage diversion project of Erhai Area in Yunnan Province，the design and analyses of the excavation with ground treatment and support of foundation pits in complex geologic condition with silts are carried out.

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TECHNIQUES AND INFLUENCING FACTORS of embankment of LIME-TREATED EXPANSIVE SOIL IN XIANGSHI Freeway

Hu Mingjian1，Kong Lingwei1，Guo Aiguo1，Wang Qing2

2004, 23 (S1): 4623-4627

[PDF] 380 KB (11)

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In order to make the embankment construction convenient for organization and management，and reduce the quality difference induced by differences in machines，techniques and levels of construction，reasonable construction techniques and methods are investigated，and the performance of the construction machines and their combination is statistically analyzed in the construction of embankment of lime-treated expansive soil in Xiangshi freeway. The reasonable machine arrangement and job practice are proposed accordingly. The influencing factors of the construction，such as grain size of soil mass，times of road mixing and field mixing，thickness of the loosening layers，and water content，speed and times of roller compaction，are analyzed. Some reasonable suggestions about the construction of expansive soil embankment in local conditions are put forward.

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ANALYSIS on CONSOLIDATION OF HIGHWAY SOFT-SOIL FOUNDATION WITH VACUUM-SURCHARGE PRELOADING

Chen Lanyun1，Zhu Jiancai2

2004, 23 (S1): 4628-4633

[PDF] 926 KB (16)

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Based on the results of the in-situ monitoring from the bridgehead test site of Jialichen bridge，the variation law of the settlement and pore water pressure with time in consolidation zone，and the surface settlement in influenced zone and the its influence on the building around are analyzed. The relationship between vacuum energy and the surface settlement，and the surface resilience after stopping vacuum pump are also analyzed. The results indicates that the combination of vacuum and surcharge preloading is the combination of pore water pressure difference in essence and that vacuum-surcharge preloading can greatly eliminate the surface settlement after the construction，which can function as a prevention against the problem of car leaping at bridge-head.

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ANALYSIS ON EARLY DAMAGE OF FREEWAY bituminous pavement

Guo Aiguo

2004, 23 (S1): 4634-4638

[PDF] 319 KB (13)

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In China，the bituminous pavement with semi-rigid base is widely used in freeway，in which the early damage phenomenon is popular. Based on practical situation of design and construction of freeway，the main reasons of early damage of bituminous pavement are analyzed，and the measures and suggestions on prevention of early damages are presented.

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MONITORING AND ANALYSIS OF THE DEEP FOUNDATION PIT OF SHANGHAI BANK BUILDING IN SOFT soil GROUND in SHANGHAI

Xu Zhonghua1，Wang Weidong2，Wang Jianhua1

2004, 23 (S1): 4639-4644

[PDF] 2243 KB (16)

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The design and construction of the deep foundation pit of Shanghai Bank Building in soft soil ground in Shanghai is introduced. Information construction technique is adopted for strict protection requirement of the surroundings. Analysis of the monitoring data shows that the design of the foundation pit is successful.

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LAW OF LOAD TRANSMISSION OF SQUEEZED BRANCH PILES AND ITS RESEARCH ADVANCES

Wang Dongpo，Qian Deling

2004, 23 (S1): 4645-4648

[PDF] 483 KB (11)

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Squeezed branch piles are a new type of piles that have good engineering properties and obvious economic benefit. The advantages of squeezed branch piles are introduced. And the mechanism of formation of piles and the law of load transmission are presented in detail. The advances and problem in this field are summarized.

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Application Of combined support technique of Mixing pile and bolt-shotcrete in deep foundation pit

Xu Yongzheng1，Wang Yuanhan1，Zhou Fang2

2004, 23 (S1): 4649-4652

[PDF] 751 KB (13)

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The combined support technique of mixing pile and bolt-shotcrete in deep foundation pits is introduced. It can be used in demanding and complicated conditions. In the supporting structure system，the bolt-shotcrete is the primary load-bearing member，and the mixing pile is the secondary load-bearing member. It can be used to increase the shear strength of soils，control the deformation of soil and improve the integral stability. The calculation method for integral stability of foundation pits supported with this technique is proposed，in which mixing pile is treated as a layer of reinforced anti-sliding soil. Therefore，the integral stability can be calculated according to the computation model of the composite bolt-shotcrete support.

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ANALYSIS ON KEY ISSUES in DEEP cement-MIXING TREATment of SOFT FOUNDATION WITH HIGH WATER CONTENT

Tang Tongzhi1，Yuan Hongyi2

2004, 23 (S1): 4653-4657

[PDF] 781 KB (14)

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The key issues in deep cement-mixing treatment of soft foundation with high water content are discussed. The results show that water content plays an important role on the strength of soil-cement and soil-cement piles. Rational mixture ratio and mixing technology should be determined according to the characteristics of soft foundation to ensure the treatment effect in practices.

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APPLICATION OF COMPOSITE SOIL NAILING TECHNOLOGY TO FOUNDATION PIT

Xu Hongfa1，Guo Shaoping2，Chen Wei1

2004, 23 (S1): 4658-4661

[PDF] 736 KB (12)

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In a foundation pit in Beijing，the composite soil nailing technology is adpoted. Prestressed anchor bolts and tube piles are added in soil nailing structures in this project，and the deformation is effectively controlled. Based on the engineering practice，the design method and execution techniques of the technology are introduced. Some problems in execution and the appropriate measures are also presented. The construction experiences are summarized for extending the application of the technology in urban areas.

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CONSTRUCTION SUPERVISION of FOUNDATION PITs IN UNSATURATED SOILs

Cao Xueshan

2004, 23 (S1): 4662-4665

[PDF] 310 KB (15)

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Foundation pits in unsaturated soil is temporary projects，the construction cost is high，the construction technology is complex，and there are many influencing factors，so supervision and quality control are important issues. Practical experience，new technologies and new theories for supervisors to deal with engineering problems，control investment and accelerate construction progress are described.

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STUDY on WATER BLOCKING AND REINFORCING by grouting AND ANCHORING METHOD in a SHAFT ABOUT ONE KILOMETER

Lin Dengge，Wu Xinhua

2004, 23 (S1): 4666-4668

[PDF] 821 KB (18)

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There exists the problem of pouring water in large quantities in the shaft about one kilometer in Tangkou mine after it is established. The new technology of water blocking with grouting and anchoring method is employed and the problem is solved economically.