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2003, 22 (S2): 2540-2540 doi:

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ISSUES OF ROCK MECHANICS AND ENGINEERING GEOLOGY IN WEST CHINA EXPLOITATION

Liu Tongyou

2003, 22 (S2): 2541-2543 doi:

[PDF] 284 KB (700)

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At present，a series of fundament construction and key projects will come into operation along with the exploitation of west China. Six important issues of rock mechanics and engineering geology are brought forward，that is，loess hydrocompaction，permafrost and seasonally frozen earth，landslide and mud-rock flow，high and steep slope，engineering geology of long deep-buried tunnel and mining in the high in-situ stress area.

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STUDY ON CHARACTERISTICS OF IN-SITU STRESS FIELD IN LAXIWA HYDROPOWER STATION

Dong Lanfeng1，Chen Wanye2

2003, 22 (S2): 2544-2547 doi:

[PDF] 1032 KB (648)

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The spacial variation characteristics of in-situ stress field in the dam axis section of Laxiwa hydropower station，and degree and range of in-situ stress concentration in the gorge are studied for selecting the appropriate dam abutment embedding depth and excavation manner.

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RELATIONSHIP BETWEEN FRACTAL OF GRAIN SIZE AND MECHANICAL PARAMETERS OF FAULT GOUGE AT LAXIWA HYDROPOWER STATION

Liu Huijun1，Sun Guanping2，Nie Dexin1

2003, 22 (S2): 2548-2550 doi:

[PDF] 323 KB (809)

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Research is made on the fractal features of fault gouges at Laxiwa hydropower station. The fault gauges are of the same fractal dimension when the fault gouges are of the same ingredients. Fault gouges are of apparent fractal feature. There is clear correlation between fractal dimension and mechanical parameter. It is a convenient to decide the mechanical parameter of weak interlayer by using this correlation.

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RESEARCH ON REASON OF ROCKMASS DIFFERENCE BETWEEN DALIUSHU AND XIAOGUANYIN DAM SITES ON HEISHAN GORGE OF YELLOW RIVER

Li Xuefeng1，Han Wenfeng1，2，Chen Wenwu1，Liang Qingguo1

2003, 22 (S2): 2551-2554

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The Daliushu dam site and the Xiaoguanyin dam site are both located on the Heishan Gorge of Yellow River. There is just a distance of 48 km between them. They also share rockmass of layers of metamorphosed feldspar-quartz-sandstone and phyllite. Large quantities of research and investigation materials show obvious difference between their rock mass quality. After contrast analysis on the rockmass wave velocity，grading of rockmass quality and permeability of dam base rockmass，the difference of rockmass quality between the two dam sites is analysed，and it is pointed out that the seism-dynamical damage is the primary cause for the formation of large scaled relaxed rockmass. Thus it is also the primary reason for rock mass difference of the two dam sites.

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GROUTING TEST AND QUALITY ASSESSMENT OF ROCKMASS FOR DAM SITE OF DALIUSHU WATER PROJECT

Chai Shouxi1，2，Wang Yinmei1，Wang Junguo1

2003, 22 (S2): 2555-2558 doi:

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The cement consumption per meter，quality of rock mass，wave velocity，land upheaval，stress status of rock mass，and the relationship among them during and after two grouting tests are discussed in the paper. The rather poor quality of relaxed rockmass results in more cement consumption in grouting test. It is certified further that the rockmass in dam site loosened extensively.

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STUDY OF FAULT DATING IN DALIUSHU DAM SITE

Liang Shouyun1，Han Wenfeng2，Chen Wenwu1，Liu Gao1

2003, 22 (S2): 2559-2563 doi:

[PDF] 476 KB (691)

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There are cognition differences in fault activities at Daliushu dam site over a long period of time. By systematically analyzing the data of fault dating and reliability of the results by distinct methods，it is found that the major faults and secondary faults in dam site are all active. Moreover，most of them can move integrally，so the problem of anti-rapture of the dam site will be very serious under the this condition.

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PERMEABILITY OF RELAXED ROCKMASS IN DALIUSHU DAM SITE

Chen Wenwu1，Sun Guanping1，Song Chang2，Li Xuefeng1

2003, 22 (S2): 2564-2567 doi:

[PDF] 386 KB (679)

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According to abundant prospecting data of irrigation works and hydropower stations and various reports of monographic study，it has been testified that there is relaxed rockmass over an extensive area at Dalushu dam site. It results in an essential leap in cognition process concerning complicated geological engineering conditions on Daliushu dam site. Both open structural surface and intensive permeability are the hydrogeological features of relaxed rockmass. Study is made on the treatment of permeable rockmass，excavation of high slopes，seepage loss and permeation stability of rockmass. The study results show that the project in such condition is of the features，such as higher difficulty of technology，huger investment，difficulty to safeguard，higher risk of policy making.

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INFORMATION INTERPRETATION OF ROCKMASS STRUCTURE BASED ON DIGITAL IMAGE

Wu Zhiyong1，Nie Dexin1，Li Xuefeng2，Zhang Jingke2

2003, 22 (S2): 2568-2571 doi:

[PDF] 673 KB (674)

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The measuring and statistical work of joints is the basis of study of rockmass quality. Traditional statistical method involves much work. In this paper，the joint features are extracted by dealing with digital image in computer. The interpretion principle is also introduced. The work efficiency can be improved and error can be reduced by using this method，meanwhile working condition is improved to great extent.

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RELATION BETWEEN DEVELOPMENT DEGREE OF JOINTS AND DEFORMATION PARAMETERS OF ROCKMASS

Wang Yi1，Nie Dexin1，Zhang Jingke2，Lei Qiyun2

2003, 22 (S2): 2572-2574 doi:

[PDF] 353 KB (723)

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The development degree of joints in rockmass is a significant factor affecting rockmass structure types，rockmass quality and comprehensive utilization of engineering rockmass，and it is important to estimate quantitatively the development degree of joints in rockmass. After introducing the classification of rockmass joints，the joint number per unit area which is equivalent to the joint number on the cave wall per 5 m is chosen as quantification index of the development degree of joints in rockmass. Then，in a hydropower station which will be built on Yellow River，the joint number per unit area is analyzed carefully by means of mathematical statistics，and then the relation between development degree of joints and deformation parameter of rockmass is studied. The presented study provides a theory basis for rockmass evaluation.

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DETERMINATION OF SPACING OF STRUCTURAL PLANE IN ROCKMASS STRUCTURE RESEARCH

Han Aiguo1，Nie Dexin1，Sun Guanping2，Li Xuefeng2

2003, 22 (S2): 2575-2577 doi:

[PDF] 308 KB (808)

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The spacing of stuructural plane is widely used in rockmass structure classification，but the method of determining the spacing in many existing schemes of rockmass structure classification is not fully demonstrated. In this paper，rational method for determining the spacing is put forward based on lots of statistical data of structural planes.

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PERMEABILITY OF WEAK INTERCALATION WITHIN ROCKMASS UNDER LOWER EARTH STRESS

Chen Wenwu1，Sun Guanping1，Song Chang1，2，Lei Qiyun1

2003, 22 (S2): 2578-2581 doi:

[PDF] 326 KB (632)

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Lower earth stress is a phenomenon that the minimum stress is no more than the minimum of self-weight stress under given conditions. Through research of recent years，it is found that there lies lower earth stress in special tectonic part in west China. Because of well developed weak intercalation in lower earth stress zone，rock mass displays strong permeability and obvious anisotropy，and fault gouge is so rare and non-continuous in rock mass that it hardly forms aquiclude. At the same time，secondary tension crack zones easily cause seepage deformation and failure. Under lower earth stress，weak intercalation within rock mass will control construction and operation of both irrigation works and hydropower station，so cautious emergency measures should be employed to deal with weak intercalation.

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SEEPAGE FEATURES OF FISSURE WATER IN ORIGINAL ROCK AND PRACTICAL CASE STUDY

Yang Huijun1，Han Wenfeng1，2，Chen Wenwu1，Liu Gao1

2003, 22 (S2): 2582-2587 doi:

[PDF] 486 KB (610)

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The fissure water in original rock threatens large-scale underground excavation，and gives rise to engineering problems such as landslide，roof caving，water bursting. The seepage features of fissure water in original rock are analyzed，and practical case study is made for the New Qidaoliang Tunnel.

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DYNAMIC EVOLUTION AND MECHANICAL PARAMETERS OF SURROUNDING ROCKS IN JINCHUAN NICKEL MINE

Liu Gao1，Han Wenfeng1，2，Li Xuefeng1

2003, 22 (S2): 2588-2594 doi:

[PDF] 358 KB (809)

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Some problems of rock mechanics involved in Jinchuan nickel mine are discussed firstly. From the view of systematology，the dynamic evolution and spatial variation of rocks and its corresponding mechanical parameters under excavation condition can be studied through analyzing some typical parameters，such as stress field，rockmass structure，mechanical parameters，at different places in this mine. Researches show that the rocks in Jinchuan mine are mostly controlled by stress field and rockmass structure and that all other factors are controlled by in-situ stresses，so the dynamic evolution and mechanical parameters of rockmasses are studied in essence from spatial and time variation of stress field. Elastic wave velocity and mechanical parameter are related to each other in nature because they are all synthetic response factors of rockmasses. The rules of the dynamic evolution of rockmasses and their mechanical parameters are achieved on the basis of elastic wave velocity.

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STUDY ON DEFORMATION AND SUPPORT OF ROADWAYS IN WEAK ROCKMASS IN JINCHUAN NICKEL MINE

Wu Aixiang1，Han Bin1，Liu Tongyou2，Yang Changxiang2，Zou Long2

2003, 22 (S2): 2595-2560 doi:

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Jinchuan nickel mine is the largest underground metal mine in China，There is highly stressed weak rockmass in this mine. The problem of roadway support in Jinchuan mine is serious. The types of rockmass is classified based on engineering geological investigation data from in-situ rock mass，The in-situ stresses，deformation laws of surrounding weak rockmass，and support methods of roadway used in the mine are presented. Using rock bolt shotcrete and wire mesh support method as a primary support，immediate support can be provided to prevent the surrounding rockmass from loosening. The presented support method also permits the surrounding rockmass to deform gradually，so that the stress of surrounding rockmass can be released to certain degree. Rock bolting and grouting serves as a secondary support. Injecting the cement grout into the cracks of the rockmass can prevent the structure of the surrounding rockmass from loosening. Therefore the self-supporting ability of the surrounding rockmass is enhanced. Moreover，using rock bolting and grouting support combined with rock bolt shotcrete and wire mesh support，multi-layer-compounding arches can be formed to increase the effective load-carrying capacity. For the roadways under high in-situ stresses，if the surrounding rockmass is stratified fractured structure or loosening structure，the primary support should be rock bolt shotcrete and wire mesh support，and secondary support should be sectional fabricated steel arch，rock bolting and grouting support，reinforced concrete support，or rock bolting and grouting together with U shaped iron bar. Generally，these measures can serve to maintain the stability of the roadway. This new technology is gradually becoming popular in Jinchuan nickel mine.

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LAW OF IN-SITU STRESS IN JINCHUAN DIGGINGS AND RESEARCH ON PREDICTION MODEL BASED ON ARTIFICIAL NEURAL NETWORK

Wang Fuyu1，Gao Qian2，Zhang Zhouping

2003, 22 (S2): 2601-2606 doi:

[PDF] 413 KB (626)

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The test result of in-situ stress in Jinchuan diggings demonstrates that the area is of higher in-situ stresses. The destruction model and stability of the tunnel largely depend on the quantity and direction of in-situ stress. As the excavation depth and in-situ stress increase，the manipulation of the field stress in the excavation area becomes harder. Thus，the disclosure of the in-situ stress law is important for optimum control technology and tunnel supporting design. The test material of in-situ stress in the diggings is collected，and the prediction model of in-situ stress is developed，based on neural network theory. The main conclusion is achieved after the prediction and analysis of in-situ stress in the digging.

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STABILITY RESEARCH OF 1~# DEPOSIT IN JINCHUAN NICKEL MINE

Ba Duoheng，Wang Yongcai

2003, 22 (S2): 2607-2614 doi:

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Jinchuan nickel mine is a famous oversize multimetal sulfuration deposit. 1# deposit body is the important part in Jinchuan nickel mine. During the mining，the geological engineering condition is complex and problems of rock mechanics are intricate. Production security and continuous development are restricted by the condition and problems. For continuous development of Jinchuan nickel mine，researches are made on these problems.

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RESEARCH ON DEEP ENGINEERING GEOLOGY AND EVALUATION ON ROCK QUALITY IN NO.2 DIGGINGS OF JINCHUAN

Yue Bin，Wang Yongcai

2003, 22 (S2): 2615-2619 doi:

[PDF] 323 KB (717)

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No.1 deposit body is the main deposit body of Jinchuan mine. It is also the body of the second exploitation period in the second mining zone. Because of deep embedding，great geopressure，high in-situ stress，many joints in rock and poor stability of wall rock，the geopressure control and maintenance of laneway stability become a key technological issue during the exploitation. In selecting the best control measure of stope and the timbering technology of laneway，the system analysis and parameter optimization，geological engineering research and rock quality evaluation are the basis of underground work. Thorough research and an on-the-spot investigation are carried out in Jinchuan deposit. On this basis，the engineering wall rocks are classified and the quality of the rocks are evaluated.

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STABILITY RESEARCH OF ROADWAY OF 1 098 M LEVEL IN DEPOSIT 2 OF JINCHUAN

Zhang Zhong

2003, 22 (S2): 2620-2624 doi:

[PDF] 389 KB (734)

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Based on stability analysis methods and site survey in Jinchuan，the surrounding rocks on 1 098 m level are classified. According to present support pattern and convergence monitoring result of the roadway，the stability of roadway is evaluated. The analysis is made on the best operation time for the first supporting，second supporting and other types of supporting used for for deep roadway of deposit 2.

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DEFORMATION RULE OF WALL ROCK AND FILLING IN DEEP STOPE IN DEPOSIT 2 OF JINCHUAN

Gao Jianke，Yang Changxiang

2003, 22 (S2): 2625-2632 doi:

[PDF] 415 KB (797)

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Because in deposit 2 of Jinchuan Company，the deep stope area will reach 10×104 m2 and the buried depth will reach 1 000 m，the key point of the second stage project is the stability of deep wall rock and filling. At the same time，the deformation feature of wall rock and filling also affects the project’s safety and normal operation. A great deal of deformation data are obtained in Jinchuan mine by many methods，such as beach mark，convergence and GPS. Based on the deformation data，the deformation rule of wall rock and filling is predicted with neural network model，and some useful conclusion is obtained.

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MONITORING RESEARCH ON CONVERGENCE DEFORMATION OF LANEWAY WAY ROCK AND OBSTURATOR IN NO.2 DIGGING OF JINCHUAN

Lu Quansheng1，Gao Qian2

2003, 22 (S2): 2633-2638 doi:

[PDF] 498 KB (699)

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The stability of stope wall rock and obsturator is a key issue for the safty of the second stage minimg in Jinchuan no.2 digging. As mining depth of the stope area and geopressure increase，stope wall rock and obsturator are of the possibility of serious yielding destruction and whole instability. In order to forecast the stability condition of wall rock and obsturator，a series of methods are applied to monitoring deformation，among which convergence monitoring is one of the main methods. The arrangement of laneway convergence monitoring net，monitoring project and monitoring result are presented，and some meaningful conclusions are obtained.

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Discussions on Environment Earthwork Problems in Permafrost Region of Qinghai-Tibet Plateau

Liang Bo

2003, 22 (S2): 2639-2642 doi:

[PDF] 316 KB (712)

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Based on the inter-constraint and inter-adjustment system balance between environment and earthwork，the environment earthwork problems in permafrost region of Qinghai-Tibet plateau is discussed with a view of macro and micro environment. Firstly，the atmosphere environment development，ground temperature zone，the suitable principle and condition of earthwork design decided by landscape ecology are discussed on macro environment aspect. Secondly，the environment changes by the constructive force of nature and the probable environment destruction and engineering hazard caused by earthwork construction are discussed on micro environment aspect. Thirdly，on the condition that the macro environment can not be controlled or can only be directed to a less worse situation by more comprehensive efforts，the principle and method are discussed for protecting environment in earthwork construction.

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NUMRICAL ANALYSIS ON FREEZING-THAWING STATE OF SURROUNDING ROCKS OF KUNLUNSHAN TUNNEL

Zhang Xianjun，Lin Chuannian，Zhang Junbing

2003, 22 (S2): 2643-2646 doi:

[PDF] 1599 KB (698)

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FEM analysis is made on freezing-thawing state of surrounding rocks of Kunlunshan tunnel. It is found that the influences of construction on temperature field of surrounding rocks at sidewall are larger than that of surrounding rocks at vault and inverted arch. The refreezing time of the residual thawed layer at sidewall is longer than that of the residual thawed layer at vault and inverted arch. The temperature field in surrounding rocks of the tunnel is not stable in the 30th year after construction of the tunnel.

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PRELIMINARY ANALYSIS ON CRACKING OF SUBGRADE IN QINGSHUIHE EXPERIMENTAL SECTION OF QINGHAI-TIBET RAILWAY

Wang Yinsheng，Jia Haifeng，Li Yong，Dou Shun

2003, 22 (S2): 2647-2651 doi:

[PDF] 893 KB (801)

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There are many cracks in subgrade in Qingshuihe experimental section after a freezing-thawing cycle. Different quantity of cracking occurs in the subgrade constructed by different engineering measures. Based on detailed investigation information of subgrade in Qingshuihe experimental section，the occurrence reason of cracking and classification of the cracking are studied. The situations of cracking in subgrade constructed by different engineering measures are also analysed.

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PRILIMINARY ANALYSIS ON ENGINEERING EFFECT OF VENTILATION EMBANKMENT AT BEILUHE TESTING SECTION OF QINGHAI-TIBET RIALWAY

Niu Fujun，Ma Wei，Lai Yuanming

2003, 22 (S2): 2652-2658 doi:

[PDF] 654 KB (802)

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Based on ground temperature record of one year at Beiluhe section of Qinghai-Tibet Railway，where field testing embankment was constructed，the engineering effect of duct-ventilation embankment is discussed. Testing results indicate that duct-ventilation embankment is available to protect the underlying permafrost and can even extend it. It is also shown that it is better to apply large-diameter ducts and to bury ducts near the initial ground surface，so that the engineering effect of ventilation embankment can be enhanced.

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PRELIMINARY ANALYSIS ON INSULATION TREATMENT OF EMBANKMENT AT BEILUHE TEST SECTION OF QINGHAI-TIBET RAILWAY

Sheng Yu，Wen Zhi，Ma Wei

2003, 22 (S2): 2659-2663 doi:

[PDF] 820 KB (748)

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The structure of test embankment and monitoring system of the insulation embankment test section in Beiluhe site of Qinghai-Tibet Railway are described. Based on the observed data of the first round year from building of the embankment，the dynamic process of the underlying permafrost，heat budget passing of insulation layer and temperature accumulation at both surfaces of insulation layer are preliminarily analyzed. Results indicate that the insulation embankment，to some extent，is of the function of protecting permafrost. A durative zero temperature zone may exist between the original ground surface and permafrost table. The heat entering insulation layer presents a serious asymmetry. The sunshiny side of the embankment absorbs much more heat than that of the shade side.

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DYNAMIC MONITORING OF THERMAL STATE FOR SHALLOW GROUND IN QINGHAI-TIBET RAILWAY EMBANKMENT

Wen Zhi，Sheng Yu，Wu Qingbai

2003, 22 (S2): 2664-2668 doi:

[PDF] 949 KB (794)

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The temperature and heat flux of shallow soil ground in Qinghai-Tibet railway embankment is dynamically monitored in Beiluhe testing measuring field. Based on the testing data，the temperature features of shallow ground in natural permafrost condition and heat variation features in the upper active layer are discussed. Dynamic variational rule of uppe active layer of permafrost after the railway embankment is introduced. Based on dynamic variational rule of the ground and the embankment，the relative variation of thermal state of permafrost induced by engineering activity is clarified and the primary effect factors are discussed.

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ANALYSIS ON MEASUREMENT RESULT OF PROBES IN FENGHUOSHAN AREA OF QINGHAI-TIBET PLATEAU

Li Yongqiang1，Han Longwu1，Cui Long2，Jia Haifeng1

2003, 22 (S2): 2669-2672 doi:

[PDF] 1234 KB (775)

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The thermal probes，as a kind of effective method to protect permafrost actively，are used widely in Qinghai-Tibet railway and some other places with permafrost distributed. Some basic situations are presented about the thermal probes used in Fenghuoshan test subgrade of Qinghai-Tibet plateau，and analysis is made on its operation state and the change of ground temperature field around it. Finally，it is concluded that the thermal probes are effective to decrease the base temperature and to protect permafrost，and thus it can be used in permafrost regions.

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APPLICATION PRINCIPLE AND PROSPECT OF THERMAL-PROBE TECHNIQUE IN COLD REGION ENGINEERING

Pan Weidong1，3，Lian Fenyu2，Deng Hongyan1，Yu Shaoshui3，Zhang Xianjun4

2003, 22 (S2): 2673-2676 doi:

[PDF] 844 KB (801)

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Thermal-probe is a unilateral heat transfer set. In this paper，the basic principles of thermal-probe working and application to engineering are discussed. The relation among some key factors is also analyzed. With field test data，the remarkable effect of thermal-probe application in cold regions engineering is discussed. In the end，the optimistic prospects of thermal-probe application and conclusion are proposed.

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TESTING STUDY ON DYNAMIC MECHANICS PARAMETERS OF FROZEN SOIL

Zhao Shuping，Zhu Yuanlin，He Ping，Wang Dayan

2003, 22 (S2): 2677-2681 doi:

[PDF] 423 KB (780)

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Testing study is made on dynamic mechanics parameters，including dynamic elastic modulus and dynamic damping ratio，of silty-clay and fine-sand which are sampled from the Qinghai-Tibet railway. Analysis is also performed on the relations among those parameters，frequencies，temperatures and water contents. The following test results are obtained. (1) Variation laws of dynamic mechanics parameters of frozen silty-clay and fine-sand are the same. (2) Dynamic elastic modulus of frozen soil will increase with increment of frequency or decrement of temperature. (3) While soil water content increases，dynamic elastic modulus of frozen soil will increase at first，and reach its maximum value when the soil are water-saturated. (4) Dynamic damping ratio of frozen soil decreases with increment of frequency or decrement of temperature. (5) Dynamic damping ratio increases slightly with increment of water content.

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STUDY ON ASEISMATIC PROPERTY OF BRIDGE PIERS IN PERMAFROST REGION

Chen Xingchong，Gao Feng，Wang Xu

2003, 22 (S2): 2682-2685 doi:

[PDF] 997 KB (657)

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Numerical simulation is made on infinite media. A viscous-spring boundary is used for simulating infinite boundary condition. The seismic responses of multifarious piers are calculated by finite element method in various grounds under various earthquake wave. The influence of frozen earth layers is analyzed. The results indicate that the stresses of piers are related to factors such as frozen earth layers，earthquake characteristics and pier property，and these factors should be considered in aseismatic design of structures.

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NUMERICAL ANALYSIS ON L-TYPE RETAINING WALL IN PERMAFROST REGIONS #br# #br#

Wang Jiadong，Liang Bo，Yan Songhong

2003, 22 (S2): 2686-2689 doi:

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The deformations and stresses of backfill of retaining wall are analyzed by elastoplastic numerical calculation model. The boundaries between backfill and retaining wall，and backfill and floor are simulated by interface elements that reflect interaction of them. The working mechanism of L-type retaining wall in permafrost region are studied and examined in detail，for providing reference for future engineering application.

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INFLUENCE OF FREEZING-THAWING ON SOIL STRUCTURE AND ITS SOIL MECHANICS SIGNIFICANCE

Qi Jilin，Zhang Jianming，Zhu Yuanlin

2003, 22 (S2): 2690-2694 doi:

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Freezing-thawing changes the mechanical properties of soil through changing its structure. In this paper，the saturated Lanzhou loess and Tianjin silty clay are taken as study objects. After all the two soils experience a freezing-thawing cycle，soil mechanics tests and SEM quantitative analysis are performed. After comparatively analyzing the data of soils before and after freezing-thawing，it is found that both mechanical properties and microstructure of the two soils are changed by freezing-thawing. Moreover，the change of mechanical properties can be explained by the change of microstructure to some extent.

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TESTING STUDY ON INFLUENCE OF FREEZING AND THAWING ON DRY DENSITY AND WATER CONTENT OF SOIL

Yang Chengsong，He Ping，Cheng Guodong，Zhu Yuanlin，Zhao Shuping

2003, 22 (S2): 2695-2699 doi:

[PDF] 401 KB (918)

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Sandy clay and sandy loam are the two typical kinds of soils along the Qinghai-Tibet railway. Under an open system environment，the two kinds of soils are tested in repeatedly freezing and thawing circulation experiments. In these experiments，all the soil samples are tested at the different dry density，water content and temperature. The results show that the final dry density is a constant after the repeatedly freezing and thawing. The final dry density of sandy clay is 1.55 g•cm－3，while that of sandy loam 1.78 g•cm－3. It can also be concluded that the final dry density of each soil sample depends on the soil type but not the original dry density. The repeatedly freezing and thawing circulation can change water content of soil. After the circulations，the water content of soil will increase，and the water content at the top part is greater than that at the bottom part due to water migration from bottom to top.

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RELATIONSHIP AMONG ELASTIC MODULUS，TEMPERATURE AND #br# STRAIN RATE OF FROZEN MEDIUM UNDER #br# STATIC LOADING #br#

Lin Chuannian1，Li Haipeng2，Zhang Junbing1，Zhu Yuanlin2，1

2003, 22 (S2): 2700-2702 doi:

[PDF] 333 KB (907)

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Uniaxial compression tests are performed on saturated frozen sand at various temperatures and strain rates. The elastic modulus is obtained from these tests. The relationship among elastic modulus，temperature and strain rate is discussed，and the formula is presented to predict the elastic modulus based on temperature and strain rate.

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STRENGTH CONTROLLING FORECAST METHOD OF CRITICAL LANDSLIDE ALONG RED-SOFT-MUDSTONE LAYER

Li Baoxiong1，2，Miao Tiande1，3

2003, 22 (S2): 2703-2706 doi:

[PDF] 785 KB (826)

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Red-soft-mudstone layer landslides of Jurassic，Cretaceous and Tertiary are widely distributed in north China. The basic characteristics of red-soft-mudstone layer are weak anti-weathering ability，low rock mass strength，and bad engineering geological property. The layer is very sensitive to water，and landslide hazards in the area of red-soft-mudstone is very serious. Geological environmental conditions of the red-mudstone layer landslides are the key factors for forming landslides. Rock mass strength characteristics determine the mechanics and deformation mechanism of landslides. The traits and moving characteristics of red-mudstone layer landslide are varied with different conditions of deformation and failure. Based on the study of rock mass strength in different conditions and shear strength of rock layer surface，the mechanisms of creep deformation and slip plane forming are systemically analyzed. The strength-controlling forecast method of critical landslide along red-soft-mudstone layer is given after statistic analysis on typical examples of red-soft-mudstone layer landslide.

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STUDIES ON DEFORMATION AND FAILURE PROPERTIES OF #br# ANTI-DIP ROCKMASS SLOPE #br#

Ren Guangming1，Nie Dexin1，Liu Gao2

2003, 22 (S2): 2707-2710 doi:

[PDF] 1117 KB (819)

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Based on the field investigation，geology analysis and numerical simulation of a large-scale slope in reservoir area on the upstream of Yellow River，the rules of deformation and failure of this kind of slopes are disclosed. The layered rock bends like cantilever under the effect of gravity. When rock mass in back of the slope bends to a certain extent，its root will break off and create a continuous weak surface，and shear creep will occur in the toe of the slope. When the shear stress excesses to the shear strength of the weak surface，the topple-slumping will occur in the shear stress concentration zone of the slope.

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PLASTIC POWER OF TRANSLATIONAL LANDSLIDE

Ma Chongwu，Miao Tiande，Yi Chenhong

2003, 22 (S2): 2711-2714 doi:

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Based on analysis of the total motion and harmonic motions of translational landslides，the evolutional rules of the plastic power of slide bodies are studied，which provide a relatively rigorous theoretical basis to the time-prediction method of landslides based on the plastic power concept.

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ANALYSIS ON RAINFALL INFLUENCE ON SLOPE DEFORMATION #br# AND FAILURE #br# #br#

Liu Xiaowei1，Liu Gao1，Chen Wenwu1，Han Wenfeng1，2

2003, 22 (S2): 2715-2718 doi:

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Rainfall is the major factor to stimulate landslide. In this paper，the influence of rainfall infiltration on slope soil mass is analyzed. The relationship between deformation and rainfall is analyzed by finite element method. It is suggested that rainfall infiltration should be considered in general analysis method for slope stability and deformation.

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DISCUSSION ON PROBLEMS OF SLOPE DISASTER AND TUNNEL DEFORMATION

Ma Huimin

2003, 22 (S2): 2719-2724 doi:

[PDF] 964 KB (800)

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Based on investigation and analysis on case histories of tunnel deformation along main railways in mountainous area of China since 1980，the tunnel deformation types，geological structure model and interaction mechanism in slope disaster section are systematically presented. The appropriate control technique is also put forward. The research result can provide reference for controlling such disasters in the future.

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IMPORTANCE OF DYNAMIC INFORMATION ABOUT SLOPE #br# CONTROL ALONG ROAD #br#

Han Long，Xiao Bi，Xu Shichun

2003, 22 (S2): 2725-2730 doi:

[PDF] 1172 KB (839)

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With the rapid development of basic communication construction in China，basic road construction is steadily increasing. The miles of roads increases and the grade of roads goes higher. In order to raise transport speed and efficiency，the line selection and road construction gradually extend from plain area to hilly and mountainous area，and consequently the problem of slope disaster is increasing. Effective control and monitoring measures to ensure safety of slope and reasonable engineering control measures are urgent and difficult technical issues. Combining the whole-process monitoring of several control engineering cases of high slopes along north section of Jingzhu express way and scientific analysis of achievement information，some primary ideas is put forward about dynamic information of slope control.

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APPLICATION OF PRESTRESSED ANCHOR CABLE TO CONTROL ENGINEERING OF HIGH SLOPE DISASTER

Wang Xiaorong，Jiang Yuhua

2003, 22 (S2): 2731-2733 doi:

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The application of prestressed cable is presented to control engineering of high slope disaster in Baolongyu experimental section and the construction technique and quality control of cable are discussed.

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APPLICATION OF PRESTRESSED ANCHOR CABLE TO CONTROL ENGINEERING OF UNSTABLE ROCKMASSES IN HEQUNXIA EXPERIMENTAL SECTION

Liu Shifeng

2003, 22 (S2): 2734-2737 doi:

[PDF] 424 KB (738)

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The construction cases are described to control the unstable rockmasses in Hequnxia experimental section，such as drilling hole，installation，grouting，extending，and prestress loss.

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SOME PROBLEMS OF ANCHORING TECHNIQUE IN #br# CONTROLLING LANDSLIDE #br#

Zheng Jing，Yu Gui，Wang Mengliang

2003, 22 (S2): 2738-2740 doi:

[PDF] 310 KB (806)

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Combining with cable practice and application，the designed tensile force，pre-stress and determination of locking load of anchor cable and shearing resistance of anchor cable at slip surface are discussed.

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DISCUSSION ON CONTROL ENGINEERING OF BACHIMEN LANDSLIDE IN SECTION A3 OF FUNING EXPRESS HIGHWAY

Liu Lizhong

2003, 22 (S2): 2741-2744 doi:

[PDF] 311 KB (711)

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Bachimen landslide is a large-scale old landslide in the accumulated layer. When the road cut is excavated to 10～15 m depth，the landslide is revival because ground water in the landslide becomes rich and shearing resistance of soil mass is reduced. The application of pressure-dispersion type of cable in Bachimen landslide is presented，and the requirements on the construction technique and quality，progress and investment control are put forward.

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LANDSLIDE CONTROL OF JIANGYOU HIGH SLOPE

Wang Zhen，Zhang Zhiqiang，Wang Mengliang

2003, 22 (S2): 2745-2747 doi:

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According to given enengineering geology condition，the occurence mechanism of Jiangyou landslide is analysed，and a comprehensive control measure is put forword. The problems existing in the engineering construction are solved by the measure.

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STABILITY-LOSING DISTRUCTION MACHANISM AND STABILITY EVALUATION OF CONSEQUENT ROCK HIGHSLOPE IN CHONGQING WANLIANG EXPQESS HIGHWAY

Jin Peijie

2003, 22 (S2): 2748-2750 doi:

[PDF] 642 KB (663)

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The geological conception model is put forward to answer the stability-losing question of the consequent high rock slope in Chongqing Wanliang express highway. The deformation failure mechanism and the control factor of stability-losing failure for consequent rock slope are analysed. At the same time，example analysis of the typical consequent high rock slope is given.

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DISASTER LAW AND STABILIZING MEASURES FOR LANDSLIDES OF LONGYAN IN FUJIAN PROVINCE

Liao Xiaoping

2003, 22 (S2): 2751-2758 doi:

[PDF] 363 KB (768)

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The landslide disaster outline of Longyan highway in Fujian province，China，is presented firstly. The disaster distribution，deformation characteristics，landslide scale，developing tendency，triggering reasons，disaster degree and stabilizing measures are studied. The disaster types，disaster mechanism and the engineering countermeasures are proposed. Meanwhile，the basic principles and methods to prevent and mitigate disasters of highway landslides in this area are proposed to guarantee the highway operation and safety.

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CONSTRUCTION TECHNIQUE AND QUALITY CONTROL OF PRESTREESED CABLES FOR STABILIZING CUTTING #br# SLOPES OF EXPRESSWAY #br#

Young Jie

2003, 22 (S2): 2759-2764 doi:

[PDF] 1455 KB (992)

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The construction technique and quality control of prestressed cables are briefly presented for stabilizing cutting slopes based on the field cases of Fujian expressway in the mountainous area. Especially，the construction technique and the practical application with prestressed cables of distributed pressure mode are introduced in detail.

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FAILURE MECHANISM AND STABILITY ANALYSIS OF #br# CUTTING SOIL SLOPES #br#

Liao Xiaoping

2003, 22 (S2): 2765-2772 doi:

[PDF] 425 KB (756)

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The slope engineering in Fujian province，China，especially the expressway construction in the mountainous area is introduced. The engineering types of slopes are outlined practically for the survey，design，construction and the uphold of the slope engineering. On the basis of study on the engineering geological models and the relative failure mechanism of similar soil slopes，a series of methods to analyze slope stability are proposed，and the principle and measure of slope reinforcement design are put forward.

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ON SHAOPUSHAN LANDSLIDE DISASTER AND ITS ENGINEERING COUNTER-MEASURES

Wang Hao1，Liao Xiaoping2

2003, 22 (S2): 2773-2777 doi:

[PDF] 1620 KB (706)

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Shaopushan landslide disaster along Beijing—Fuzhou expressway is briefly introduced. Researches are made on the occurrence mechanism and deformation characteristics of landslide according to disaster characteristics. The landslide stability and its effect on the expressway under construction are appraised，and the reliability of reinforcement work is evaluated. The principles for preventing and mitigating the landslide disaster of this type are put forward.

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ANALYSIS ON ACCUMULATION STATE OF DEBRIS FLOW

Yang Zhongcun

2003, 22 (S2): 2778-2782 doi:

[PDF] 1798 KB (805)

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The mechanical behaviour of debris flow agrees with Bingham pattern in general. The movement of debris flow requires overcoming the ultimate shearing force. Thus the debris may be accumulated in the valley and form a fan at the mouth. It used to be believed that the accumulation is the same in thickness and non-silting slope bases exist. But according to observation，survey and model experiment，in fact，the thickness along the accumulation is different. An accumulation equation of debris flow is established according to the assumption of different thickness. The computation is made of accumulation state approximate to the fact，and new viewpoints on debris flow is formed，that is，debris flow may move and be accumulated on any slopes，with different state and quantity.

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DISCUSSION ON ROCKMASS FAILURE UNDER SEISMIC LOAD #br# #br#

Liang Qingguo1，Han Wenfeng1，2，Chen Wenwu1，Wang Shengxin1

2003, 22 (S2): 2783-2788 doi:

[PDF] 516 KB (811)

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The failure of rockmass under seismic load is an intercrossing problem of multi-discipline，such as rock mechanics，engineering geology，earthquake engineering and seismology. In this paper，the two important dynamic loads，rock blasting and earthquake，are discussed firstly，and then the dynamic stress induced by seismic wave propagation and the strength characteristics of rock mass are compared. It is concluded that the main cause of rock mass failure under seismic load is tensile fracture of rock material and failure of discontinuities. The limit depth of rockmass failure under seismic load is put forward，and the important influences of in-situ stress and topography on types and extent of rockmass failure under seismic load are analysed.

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ANALYSES ON SEISMIC RESPONSES OF GROUND

Gao Feng，Yan Songhong，Chen Xingchong

2003, 22 (S2): 2789-2793 doi:

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The changes of earthquake acceleration in bed rock after transiting in horizontal soil layers are calculated by using the method of equivalent linearization. The influence of frozen earth layers and radiant damps of groundwork is considered and back-analysis is performed. The results indicate that the factors of radiant damps of groundwork and changes of seasons should be considered in seismatic design of structure.

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SIMULATION ON NEAR-SOURCE GROUND MOTIONS OF 1988 SUNAN EARTHQUAKE BY STOCHASTIC METHOD

Lu Yuxia，Shi Yucheng

2003, 22 (S2): 2794-2799 doi:

[PDF] 1257 KB (727)

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At present，two main stochastic models，point-source model and finite-fault model，are adopted to simulate ground motions. In this article，the stochastic point-source model is adopted to simulate the minor-moderate magnitude Sunan earthquake (ML=4.5，19 December 1988) and the result is reasonable. The stochastic point-source model and finite-fault model are used to simulate near-source strong ground motions for Sunan strong earthquake (Ms=5.7，22 November 1988)，and the results show that the finite-fault effect should be considered in near-source ground motion estimation.

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ESTIMATION ON SEISMIC SAFETY OF NANJING CHANGJIANG SUBMERGED TUNNEL

Yan Songhong，Gao Feng，Li Dewu，Pan Changshi

2003, 22 (S2): 2800-2803 doi:

[PDF] 814 KB (858)

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The earthquake responses of Nanjing Changjiang Submerged Tunnel of highspeed railway are analyzed by using seismic response analysis model of submerged tunnel and the dynamic model of plane finite element. The seismic safety and stability of the tunnel under earthquake loading are estimated.

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SEISMIC SAFETY EVALUATION METHODS FOR GROTTOES

Shi Yucheng1，2，Cai Hongwei1，2，Xu Huiping1，2

2003, 22 (S2): 2804-2808 doi:

[PDF] 350 KB (694)

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According to the features of grottoes，the principles and basis for seismic design are studied. The seismic safety evaluation method for grottoes is discussed from aspects of seismic load determining，seismic stability and engineering protection measures.

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#br# STABILITY ANALYSIS OF TIANCHI LANDSLIDE-DAM #br# UNDER EARTHQUAKE #br# #br#

Liu Huijun1，Sun Guanping2，Liu Xiaowei2

2003, 22 (S2): 2809-2812 doi:

[PDF] 1702 KB (723)

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Analysis is made on the factors affecting the stability of Tianchi landslide-dam under earthquake. The analysis result shows that Tianchi landslide dam is stable and will not exert bad effect on the Jishixia hydropower station under earthquake.

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STABILITY ANALYSIS OF ABUTMENT SLOPE UNDER EARTHQUAKE

Li Dewu1，2，Liangbo2，Han Wenfeng1

2003, 22 (S2): 2813-2818 doi:

[PDF] 641 KB (766)

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Based on the elasto-plastic，two-dimensional non-linear static finite element method，the static stability of an abutment slope is analyzed，and the computation result will be considered as the original stress. Then the stability of the abutment slope under earthquake is analyzed. By contrastive analysis of three positions of abutment and four kinds of base forms，the reasonable schemes about abutment positions，base form and project measures are put forward.

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CHARACTERISTICS OF ELASTIC WAVE AND ITS APPLICATION TO XIAOGUANYIN DAM SITE ON YELLOW RIVER

Liu Gao1，Chen Wenwu1，Liang Shouyun1，Han Wenfeng1，2

2003, 22 (S2): 2819-2823 doi:

[PDF] 319 KB (750)

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On the basis of elastic wave velocities recorded on the walls of adits and between adits by penetration method，the spatial distribution characteristics of wave velocities of rockmass in Xiaoguanyin dam site on the Yellow River are analyzed. It is shown that elastic wave of this area is related to in-situ stress field whose main component is gravity. The relationship between wave velocity and mechanical parameters of rock mass is established. By the means of elastic wave velocities，the relationship between mechanical parameters and earth stress field is established. By means of these results，it is feasible and easy to obtain or estimate reasonable mechanical parameters that are necessary for evaluation，calculation and analysis in those places where field test is not easy to be carried out.

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STUDY ON STATIC AND DYNAMIC BEHAVIOURS OF RAILWAY ROADBED FILLED WITH FLYASH

Yin Yaxiong1，Liang Bo2，Wang Shengxin1

2003, 22 (S2): 2824-2828 doi:

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Under different conditions of water content，compaction and stress level，the flyash from power station of Baotou steel plant is tested in project practice. The static and dynamic behaviours of flyash are analyzed and summed up according to the test results，which provides basis for its application as filling materials for railway roadbed.

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MICRO-ANALYSIS ON SEISMIC SUBSIDENCE #br# CHARACTERISTICS OF LOESS #br#

Shi Yucheng 1，2，Li Lan2

2003, 22 (S2): 2829-2833 doi:

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Loess is distributed widely in China and the seismic subsidence is one of the major disasters in loess areas. In this study，the subsidence deformation characteristics of loess structure under earthquake loading are organically combined with the microstructure characteristics. By electronic-microscope scanning，the microstructure and grain shape of loess are analyzed，the influence of middle-large pores on loess seismic subsidence is discussed，and the relationships among microstructure，seismic subsidence coefficient and critical dynamic stress of loess are disclosed.
Key words soil mechanics，loess，seismic subsidence，microstructure，overhead pore

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PREDICTION METHOD OF SEISMIC SUBSIDENCE OF LOESS #br# GROUND WITH SHEAR WAVE VELOCITY #br#

Chen Yongming1，2，Wang Lanmin1，2，Lui Hongmei1，2

2003, 22 (S2): 2834-2839 doi:

[PDF] 1208 KB (818)

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Based on dynamic test and wave velocity data of loess，the statistic relationship between shear wave velocity and seismic subsidence of loess is established. The prediction method of seismic subsidence of loess ground is proposed. The calculation result of seismic subsidence of loess ground under different seismic intensities，especially that of reversed value from Yongdeng earthquake shows that the value of seismic subsidence with normalized water content has a close relationship with shear velocity and dynamic stress，and the relationship can be used to assess the seismic subsidence of loess ground.

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DYNAMIC CHARACTERISTICS AND SEISMIC RESISTANCE OF LOESS GROUND TREATED WITH DYNAMIC COMPACTION

Wang Lanmin，Yuan Zhongxia，Wang Jun，Shi Yucheng

2003, 22 (S2): 2840-2847 doi:

[PDF] 3066 KB (670)

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Loess is water collapsible and vulnerable under earthquake. Through laboratory testing study on the dynamics constitutive model，elastic modulus，damping ratio，seismic subsidence and liquefaction and field test on wave velocity and ground tremor of loess ground treated with dynamic compaction，the effect of dynamic compaction on the seismic resistance of loess ground is evaluated quantitatively. Accordingly，the technical criteria for combinative treatment of loess ground for seismic subsidence and water collapsibility are proposed.

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APPLICATION STUDY OF IMPACT COMPACTION TECHNOLOGY TO IMPROVEMENT OF COLLAPSIBLE LOESS ROADBED

Wang Shengxin1，Han Wenfeng1，2，Chen Wenwu1，Liang Qingguo1

2003, 22 (S2): 2848-2852 doi:

[PDF] 473 KB (715)

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A new technology，impact compaction technology in improving collapsible loess roadbed，is studied. The effects of the improvement are analyzed qualitatively and quantitatively，both in macroscale and microscale， through routine soil tests and microstructure testing methods such as scanning electron microscope and mercury intrusion porosimetry. The improvement mechanism of the technology is discussed and reasonable parameters for roadbed construction process are put forward as to provide theoretical basis as well as practical experience for the promotion of this new technology in the loess regions.

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RELIABILITY ANALYSIS OF TUNNEL LINING STRUCTURE BY RESPONSE SURFACE METHOD

Zhao Xufeng，Yan Songhong

2003, 22 (S2): 2853-2856 doi:

[PDF] 440 KB (696)

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The statistic characteristic analysis of loading effect is a complex problem for reliability analysis of tunnel lining structure. The specific properties of probability about loading effect on tunnel lining structure are analyzed by FEM response surface method，and the structure reliability index is calculated by fractile method.

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INFLUENCE OF SIDE-PRESSURE COEFFICIENT ON MECHANICAL BEHAVIOUR OF TUNNEL LINING

Zhao Dean，Cai Xiaolin，Chen Zhimin，Li Shuangyang

2003, 22 (S2): 2857-2860 doi:

[PDF] 748 KB (738)

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The influence of the side-pressure coefficient on the mechanical behaviour of tunnel linings is analysed. The analysis is based on the Austrian geotechnical software，FINAL，which considers the elasto-plastic behaviour of geomaterials，the function of bolts in tunnel and the stress release situation in tunnel excavation. The results show that the forces and displacements can vary in 15% while the side-pressure coefficient varies from 0.15 to 0.75.

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#br# COMPARATIVE TESTING STUDY ON STRENGTH BEHAVIOUR OF UNDISTURBED AND REMOLDED FROZEN CLAY #br#

Li Haipeng1，Lin Chuannian2，Zhang Junbing2，Zhu Yuanlin1

2003, 22 (S2): 2861-2864 doi:

[PDF] 722 KB (865)

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Comparative testing study is made on uniaxial compressive strength of undisturbed and remolded frozen clay in the same conditions. The test results show that the compressive strength of the undisturbed frozen clay is slightly lower than that of the remolded frozen clay，and the elastic modulus of the former is slightly higher than that of the later. There are significant differences of the failure mode and failure strain between the undisturbed and remolded frozen clay. The undisturbed frozen clay usually takes on typical brittle failure character，and its failure strain is smaller. Whereas，the remolded frozen clay usually takes on typical ductile plastic failure character，and its failure strain is greater. These differences should be taken into account in the design and construction of artificially frozen ground engineerings.

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COMPRESSIVE STRENGTH OF SATURATED FROZEN SILT UNDER CONSTANT STRAIN RATE

Zhang Junbing1，Li Haipeng2，Lin Chuannian1，Zhu Yuanlin1，2

2003, 22 (S2): 2865-2870 doi:

[PDF] 438 KB (686)

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Uniaxial compressive strength tests are conducted on the saturated frozen Lanzhou silt (loess) under various constant strain rates and various constant temperatures. From the test results，it is concluded that (a) compressive strength is very sensitive to temperature and increases exponentially as temperature decreases，(b) compressive strength is sensitive to strain rate and increases exponentially as strain rates increase within certain range，(c) compressive strength decreases exponentially as failure time increases，and (d) compressive strength of the saturated frozen silt with higher dry density is higher than that of frozen silt with lower dry density. The increment rate of compressive mainly depends upon strain rate.

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BEHAVIORS OF STRENGTH AND DEFORMATION OF FROZEN SOIL WALL IN ARTIFICIALLY FROZEN SHAFT

Mai Wei，Chang Xiaoxiao，Wang Dayan

2003, 22 (S2): 2871-2874 doi:

[PDF] 361 KB (665)

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For frozen Lanzhou sandy soil and loess at the K0DCF test mode，it is found that the stress-strain curves are similar to ideal rigid plastic ones under unloading，but the stress-strain curves of sandy soil and loess are different in the sections of K0 consolidation. The yield strength increases linearly with increment of confining pressure and decrement of temperature. The yield strength of frozen loess is obviously larger than that of the frozen sandy soil. The failure strain also increases linearly with confining pressure. With decrement of temperature，for frozen sandy soil，the failure strain decreases，while for frozen loess，the failure strain increases gradually.

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MAIN DISEASES AND THEIR CAUSES OF EARTHEN RUINS IN ARID REGION OF NORTHWESTERN CHINA

Zhao Haiying1，Li Zuixiong1，2，Han Wenfeng1，3，Wang Xudong2，Chen Wenwu3

2003, 22 (S2): 2875-2880 doi:

[PDF] 838 KB (667)

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After a lot of site investigations，analyses and tests in the laboratory，it is found that the earthen ruin sites now existing in the arid regions of northwestern China have multi-diseases，which mainly take the forms of the backoff of wall bases，holes or cancellations，scaling off，cracks and collapses. All these diseases mentioned above are caused by wind erosion，rainfall erosion and repeated eutectic salt dissolving. This finding will play an important part in guiding us to protect the earthen sites in the areas concerned.

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ENGINEERING PRACTICE FOR SEEPAGE TREATMENT OF A HAN DYNASTY TOMB BY COMPREHENSIVE METHOD

Liu Ling

2003, 22 (S2): 2881-2882 doi:

[PDF] 269 KB (695)

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The cause of coffin chamber seepage in a Han dymasty bomb is analysed，and comprehensive method is adopted to track and determinate the seepage path. Grouting，filling，draining and packing are comprehensively used to solve the seepage problem in engineering practice.

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STRENGTH CHARACTERISTICS OF SAND FIXATED BY SH

Wang Yinmei1，2，Sun Guanping 1，Chen Wenwu1，Ding Liang1

2003, 22 (S2): 2883-2887 doi:

[PDF] 453 KB (818)

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SH is a new polymeric material of chemical sand-fixation. It is necessary for this material to be used in modern desert engineering. In this paper，the compressive strength of SH-fixated sand and its characteristics are studied through a great deal of laboratory experimants. The strength may reach 1 MPa if the sample is compacted slightly. The percentage of streagth loss is lower than 25% after 20 times of freezing-thawing. The strength increases 8.9% after being shined for 300 hours of intermission radiation. The sand fixated with SH is not only of high strength，but also shows good resistance to freezing-thawing and aging. SH is an effective material for sand-fixation.

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TESTING STUDY ON LOESS CONSOLIDATED BY LD SERIAL ROCK-SOIL CEMEDIN

Wang Shengjun1，Han Wenfeng1，2，Wang Yingmei1

2003, 22 (S2): 2888-2893 doi:

[PDF] 408 KB (754)

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Gel，as the product of chemical reaction，can cement soil particles. The characteristics of gel can be used to consolidate soil，which is named as soil chemical consolidation. Chemical consolidation can improve structural state of loess，increase its bearing capacity，and improve its original engineering geological properties，namely settlement by soaking，disintegration and higher compression. In this paper，the consolidation mechanism of LD serial rock-soil cemedin developed by Lanzhou University is introduced. The optimization test of strength，disintegration test and frost-resistance test are conducted on loess consolidated by LD serial rock-soil cemedin to analyze its engineering geological characteristics. The major factors that influence the strength of consolidated loess are also studied. The test results show that loess consolidated by LD serial rock-soil cemedin agent (especially LD-3# and LD-4# rock-soil cemedin) is of better physico-mechanical property and greater frost- resistant ability than pure loess. It can be concluded that LD serial rock-soil cemedin is a kind of ideal cemedin.

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RELIABILITY RESEARCH OF LOESS ON ELIMINATING #br# COLLAPSIBILITY WITH PRESSED PILES #br#

Jiang Hongying1，2，Lu Jinbu2，Miao Tiande1

2003, 22 (S2): 2894-2898 doi:

[PDF] 673 KB (696)

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The composite foundation of lime-soil pressed piles in the collapsible loess area is investigated. The interval，diameter，and length of piles are determined by means of reliability theories. The reliability design method is put forwards for pressed pile.

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CALCULATION AND MONITORING ANALYSIS ON SETTLEMENT OF PILE-RAFT FOUNDATION

Zhang Hua1，Yan Yumin2，Feng Wanjing3，Ai Donghai1

2003, 22 (S2): 2899-2902 doi:

[PDF] 654 KB (562)

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Three different methods are introduced to calculate foundation settlement. Then the settlement calculation is made on rammed enlarged bearing pile foundation by using the above methods，and is compared with the values obtained from static loading test on single pile and monitoring on building settlement. It is shown that the calculation value by using the regional regulation is closer to the real settlement value of pile top from static loading test on single pile.

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STUDY ON BEHAVIOR OF BORED PILES WITH GROUTED-BASE ON GRAVEL STRATUM

Wang Xu1，Zhao Shanrui2，Ding Xiaojun1

2003, 22 (S2): 2903-2907 doi:

[PDF] 2561 KB (708)

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Slurry drilling method is widely employed in pile construction. Sediments at base and clay slurry along hole shaft cannot be avoided in construction procedure with this method. Engineering practice proves that base sediments and slurry can severely reduce the pile’s bearing capacity and increase the settlement of the bored cast-in–situ piles. Based on the results of the field experiments，the bearing features of cast-in-situ bored piles with grouted toe in gravel bearing stratum are analysed. It is pointed out that the friction of cast-in-situ bored piles (lenth/diameter ratio of 54.1～57.1) with grouted toe in gravel bearing stratum is three times of that of the commom bored piles. The settlement of the bored cast-in-situ piles with grouted toe can be largely decreased. Most of deformation of bored cast-in-situ piles with grouted toe is elastic，and residual deformation is quite small. The experiment results can give some references to pile construction and design.

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TEST AND EVALUATION ON SOFT GROUND STABILIZED #br# BY CHEMICAL INJECTION CHURNING PILE OR CHEMICAL CHURNING PILE #br#

Wang Xiaojun，Chu Huadong

2003, 22 (S2): 2908-2912 doi:

[PDF] 348 KB (722)

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The geological condition，basic physico-mechanical properties and treating measurements of K35+930～K36+410 section of Yinjiazhuang—Zhongchuan Airport highway are described. The main procedures of field loading test，its technological points and the stability standard are introduced. The research is based on the engineering practice of twenty two chemical injection churning piles，four chemical churning piles，four blocks of ground between chemical churning piles and six blocks of composite ground with three piles in two sections. The test results are analysized and evaluated.

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ESTIMATION ON BEARING CAPACITY OF COMPOSITE FOUNDATION WITH LIME-SOIL PILES

Han Longwu，Zhang Junde，Jiang Yuhua，Zhao Chengjiang

2003, 22 (S2): 2913-2915 doi:

[PDF] 404 KB (700)

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The composite foundation with lime-soil piles，as a kind of economical and reasonable foundation treatment method，is used widely. The bearing capacity of this kind of foundation is estimated according to the working principle of foundation and the basic physical properties of soil. The study result is useful to the design and construction of lime-soil pile.

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TESTING STUDY ON REINFORCED EARTH RETAINING WALL ALONG YANGQUAN-SHEXIAN RAILWAY

Yin Yaxiong，Pan Baotian，Wang Shengxin

2003, 22 (S2): 2916-2919 doi:

[PDF] 1139 KB (700)

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Tests are carried out on the reinforced earth retaining wall along both sides of Yangquan-Shexian railway in Shanxi province. Characteristics of the deformation of metope，distributions of earth pressure on the wall and stress of base are analyzed. The research results testify the rationality of the design according to the simplified 0.3 H method，and provide reference for the design and application of reinforced earth retaining wall.

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DISCUSSION ON SUBSIDENCE PROBLEM OF MAN-BORED CAST-IN-PLACE PILE IN HIGH EARTH FILL SECTION WITH HIGH COLLAPSIBILITY

Wei Jiazhong，Shang Jihong

2003, 22 (S2): 2920-2924 doi:

[PDF] 918 KB (733)

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Man-bored cast-in-place pile foundation in collapsible loess area，especially in high earth fill section with high collapsibility，often causes subsidence by some reasons and consequently deformation accident of buildings. Based on typical case histories of man-bored cast-in-place pile foundation subsidence of several buildings in certain zone of Lanzhou，the reason of pile subsidence in this zone is analysed and several treatment measures are discussed.

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STUDY ON ANTI-SEEPAGE TREATMENT OF BAYI RESERVOIR DAM

Lin Feng1，Zhou Caigui1，2，Gao Xiongjie2

2003, 22 (S2): 2925-2928 doi:

[PDF] 427 KB (938)

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Compared with bored pile，underground diaphragm wall is an environment friendly way with some advantages，such as low disturbance and high efficiency. Impervious wall of plastic concrete is adopted for its combined action with the earth dam. The construction scheme and technique，used in the anti-seepage treatment of Bayi reservoir dam，are introduced，with a method of dealing with special underground structure inside the dam. Efficiency is improved through adoption of interleaving constructing and optimized scheduling for equipments. Further study on impervious wall of plastic concrete is needed.