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2004, 23 (13): -0 doi:
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BREAKAGE MECHANICS OF GEOMATERIAL——STRUCTURE TYPES AND LOAD SHARING

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2004, 23 (13): -2137 doi:
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[PDF 200 KB] (1062)

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Breakage mechanics is a new theory different from fracture mechanics and damage mechanics. In this paper the methodology of examination for geomaterial in three levels，macro-level，meso-level and micro-level，is introduced in detail，and the geomaterials are divided into four structural types，fragmentation structure，scatter mass structure，envelope structure and suspension structure. The principles to determine the load sharing ratio between structure bodies and structure surfaces for each structural type are discussed. At last，some meaningful conclusions are obtained for the development of breakage mechanics of geomaterial.

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NONLINEAR UNIFIED STRENGTH THEORY OF ROCK
UNDER HIGH STRESS STATE

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2004, 23 (13): -2143 doi:
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[PDF 426 KB] (820)

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The Hoek-Brown failure criterion and the generalized Hoek-Brown failure criterion are widely used in rock engineering. But the criteria need improvements as they do not consider the effect of the intermediate principal stress. A couple of twin shear stress models are presented to take account of the twin shear stresses by Yu Maohong，two normal stresses and two or one smaller principal stress. Based on these models，the unified strength theory by Yu Maohong，the nonlinear unified strength criteria and generalized nonlinear unified strength criteria proposed by Zan Yuewen，Yu Maohong and Wang Sijing can be established. Meanwhile the Hoek-Brown failure criterion is one special case of them. Rock’s failure mode transfers from brittle failure to ductile failure when its stress state develops from low level to high level. The proposed criteria are of clear physical concept and wide prospect of application

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2004, 23 (13): -2149 doi:
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[PDF 466 KB] (875)

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DETERMINATION OF COMPREHENSIVE SHEAR
STRENGTH FOR JOINTED ROCK MASSES IN 3D CONDITION USING GENETIC ALGORITHM AND MONTE-CARLO METHOD

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2004, 23 (13): -2157 doi:
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[PDF 340 KB] (934)

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Making full use of the results of two-dimensional research and the excellent properties of Genetic Algorithm and Monte-Carlo Method，a method is presented to find the combinations of joint and rock bridge associated with the least comprehensive shear force in simulated 3D joint maps and determine the shear strength and persistence property of jointed rock masses. This method is able to reflect the main factor which controls mechanical properties of a rock mass，for it takes into account the distribution characteristics of 3D joints. The calculation results of two examples are in accordance with the results of back analysis，and the method is proved to be reasonable.

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WAVE VELOCITIES，MODULUS，FATIGUE DAMAGE OF SANDSTONE UNDER LOW CONFINING PRESSURE AND CYCLIC LOADING(I)：ACOUSTICS CHARACTERISTICS OF ROCK

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2004, 23 (13): -2164 doi:
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[PDF 292 KB] (1027)

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Triaxial dynamic fatigue tests are conducted on sandstone under temperature of 30℃～125℃，confining pressure of 30 MPa and axial pressure of 40.7 MPa，with sine-wave frequency 0.05～5 Hz and its amplitude of 5.1 MPa. The results indicate that elastic wave velocities VP，VS and Young’s modulus E of sandstones are all decreased and then increased with temperature，and they display strong dispersion effect with frequency. There exists a large variation of velocity with temperature and frequency, which can be applied as the omens of earthquake or fatigue damage.

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WAVE VELOCITIES，MODULUS，FATIGUE DAMAGE OF SANDSTONE UNDER LOW CONFINING PRESSURE AND CYCLIC LOADING(II)：MECHANICS CHARACTERISTICS OF ROCK

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2004, 23 (13): -2168 doi:
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Velocities such as VP，VS1，VS2 all increase with axial stress，but decrease with temperature. The curve of average strain versus cyclic number or time is obtained. Similar to a creep curve，the curve can be classified to three stages. Heat-damage and fatigue-damage are accumulated with the increment of cyclic numbers and temperature，which worsen the structure，lower the strength and attributes to the failure of rocks. This research is helpful to design underground engineering and nuclear reservoir.

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COLLISION ANALYSIS AND PARALLEL OPTIMUM RESOLUTION FOR DYNAMIC CONTACT ACTION

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2004, 23 (13): -2172 doi:
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[PDF 203 KB] (997)

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Numerical analysis is made on consolidation mechanism of foundation soil with large deformation hypothesis. Based on collision theory，the concepts of collision coefficient and equivalent collision mass of foundation are proposed. and the dynamic contact condition is also established. Based on energy conservation principle，an energy supplement equation is obtained using optimum model and network parallel computing technology. A dynamic compaction case is taken as an example to analyze with the proposed method. The variation law of foundation displacement with time and the dynamic contact stress under dynamic compaction is obtained，which offers an effective path to analyze consolidation mechanism of soil precisely and also demonstrates the speedup and efficiency of parallel computing.

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PROBABILITY DISTRIBUTION OF ROCK MECHANICS PARAMETERS BY USING MAXIMUM ENTROPY METHOD

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2004, 23 (13): -2177 doi:
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[PDF 247 KB] (1344)

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Maximum entropy (ME) method is used to generate probability density functions of rock mechanics parameters from sample data. The Lagrangian function is introduced to infer the analytical form of the ME density function. The Newton iteration method is combined with Kolmogorov-Smirnov test in order to determine the parameters of the ME density function and assess the availability of ME density function. A few examples are used to illustrate the applicability of proposed method. Two classical distributions，the normal distribution and the exponential distribution，are compared with the corresponding ME density functions generated from the moments. Little differences are found out between classical distribution and its corresponding ME density function. The ME density function of a rock uniaxial compressive strength is generated using the moments about the origin. Kolmogorov-Smirnov test is used to verify the ME function. The results of the case study show that the ME function is accurate enough and can be used in stochastic reliability analysis of rock engineering.

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DETERMINATION AND APPLICATION OF MECHANICAL PARAMETERS FOR JOINTED ROCK MASSES

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2004, 23 (13): -2182 doi:
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[PDF 288 KB] (1124)

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Based on the data of deformation and strength of rock from test and the statistic structure plane data of rock masses from site，the damage mechanics and Hook-Brown criterion are applied to estimate the deformation and strength parameters of jointed rock masses. The parameters are used for numerical simulation of rock mass engineering. An application case study of this method in the high rock slope of Sanmen Nuclear Power Plant is presented in this paper.

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MODELING THEORY OF RANDOM MEDIA WITH CRACK NUMBER DENSITY OF SPATIAL DISTRIBUTION

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2004, 23 (13): -2187 doi:
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[PDF 275 KB] (929)

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The model of cracked media with crack number density of spatial distribution is presented according to the theory of spectral factorization in stochastic process and Hudson′s model of cracked media. The random distribution of crack number density is characterized by a 2D exponential ellipsoidal function or Gaussian auto-correlation function in this paper. Hudson′s crack model can connect micro parameters of cracks，crack number density, with macro mechanical properties. By taking the advantage of Hudson’s crack model，the real heterogeneous anisotropic medium can be effectively modeled. Numerical example indicates that the random distribution characteriztics can be different for different elastic constants under the same random distribution of crack number density. By changing the value of the auto-correlation length pair，it is possible to model the difference of the distribution in the two coordinate directions. The random media can be modeled with different stochastic characters by choosing different auto-correlation function. In other words，the Gaussian function describes the single-scale，smooth heterogeneous media and the exponential function describes the multi-scale self-similar heterogeneous media.

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3D NUMERICAL MODELING OF POSSIBLE FAILURE ZONE WITH UNDERGROUND EXCAVATION

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2004, 23 (13): -2192 doi:
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[PDF 216 KB] (980)

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The rockmass failure with underground excavation often results from local instability. The initial failure position is the weak part of surrounding rockmasses. The failure of surrounding rockmasses may be caused by lower strength of rockmasses somewhere or by concentration of stress by excavation. 3D finite element modeling is made to study the stability of the surrounding rockmasses of Tai’an pumped storage powerstation. The numerical study shows that the weak position is not located at the middle of the powerhouse，but at the part with certain distance to one end of the power house. Therefore，the support design based on 2D numerical simulation is not safe，which shows that the weak position is located at the middle part of the powerhouse，and the support design based on 3D numerical modeling should be taken instead.

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AMENDED MODEL OF BOLT ELEMENT
IN FLAC AND ITS APPLICATION

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2004, 23 (13): -2197 doi:
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[PDF 279 KB] (1222)

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It is shown from the in-situ monitoring and laboratory experiments that the declining，function-losing，damaging and softening，are the mechanical characteristics of rock bolts in roadways with large deformation. So the model of bolt element in FLAC3.3，a software，is amended to simulate the process of damaging and softening of rock bolts. The research result has been successfully applied in practical works.

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DETERMINATION OF PAREMETERS FOR BOLTS IN STRONG EXTRUSION TUNNEL

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2004, 23 (13): -2201 doi:
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[PDF 235 KB] (937)

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The previous design methods of bolt in tunnel are based on empirical analogy and simple theoretical method. Because monitoring data and relative factors are not fully considered，the reasonality and safety of design by them are not assured in complex and variable circumstances and they cannot be applied in the cases without analogous examples. So based on the first case of strong extrusion tunnel in China，the determination of rock bolt parameters in strong extrusion tunnel is discussed. A method based on the logarithm spiral angle is put forward in this article. And its application is discussed in detail. It is presented that the zone where the bolts are affected by surrounding rocks can be divided in two zones，the vertical tension zone and the strong extrusion shear zone or the horizontal tension zone. And the load with which surrounding rock acts on bolts is also given. Based on the case of Jiazhuqing tunnel，the process of the method is illustrated and the method is proved.

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APPLICATIONS OF FIBER REINFORCED PLASTIC(FRP) BOLTS

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2004, 23 (13): -2205 doi:
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[PDF 230 KB] (1663)

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The applications of fiber reinforced plastic(FRP) bolts in rock and soil engineering are a highlighted topic in civil engineering research. The material development，constituent components and manufacture process of FRP bolts are presented，and the advantages of FRP bolts and the application of them to the field are discussed. The design problem of FRP is also analyzed.

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INHOMOGENEITY ANALYSIS OF DAMAGE UNDER UNIAXIAL TENSION(II) ——LOCALIZED DAMAGE

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2004, 23 (13): -2211 doi:
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[PDF 139 KB] (915)

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Influences of constitutive parameters，such as elastic modulus，softening modulus and internal length parameter，on localized damage are investigated analytically. In the strain-softening stage beyond the peak strength，both damage variable and damage variable rate are concentrated into the narrow localized band whose width depends on internal length parameter of rock material. Local damage variable increases as flow tensile stress acting on the band decreases. Higher softening modulus leads to lower local damage variable. The larger the elastic modulus is，the larger the local damage variable is. The relationship between maximum local damage variable at the center of the band and flow tensile stress becomes flat as softening modulus increases or the elastic modulus decreases. The influences of softening modulus and elastic modulus on local damage variable rate depend on the flow stress level. At higher stress level approaching peak strength，local damage variable rate increases with decreasing softening modulus. However，at lower stress level，it increases with softening modulus. Lower internal length parameter causes higher gradients of local damage variable and local damage variable rate. Whether internal length parameter is large or not，maximum local damage variable and maximum local damage variable rate remain constants，which is different from previous numerical predictions. As elastic modulus increases or softening modulus decreases，maximum local damage rate-flow stress curve approximately becomes linear.

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NUMERICAL COMPUTATION OF NONLINEAR SEEPAGE FOR
MINE WASTE DUMP

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2004, 23 (13): -2215 doi:
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[PDF 212 KB] (915)

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The seepage in waste dump of mine is complicated. Based on the nonlinear seepage formula，a numerical model of seepage in waste dump is established. A case study shows that nonlinear seepage exists in all the seepage area of the waste dump and the water level is higher than that of linear seepage. Therefore，the seepage computation using nonlinear seepage model is suitable and safe for mine waste dump.

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CHARACTERASTIC ANALYSIS OF DYNAMIC FIELD PARAMETERS
FOR TIANWAN NUCLEAR POWER STATION PROJECT

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2004, 23 (13): -2220 doi:
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[PDF 200 KB] (919)

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The geological condition，seismic wave test and dynamic parameter analysis are the important contents of feasibility research of the site of a nuclear power. According to the analysis of regional geological characteristics，the field geological condition，the field drill sampling and the test results of lab，single-hole seismic wave test in the field and lab are carried out for 8 holes in the main architectural zone of Tianwan Nuclear Power station project in Jiangshu Prwince，and the dynamic parameters of rock mass in the field are btained using shear wave and compression wave combined with the gravity of the rock mass. The relationship is built up among wave velocity，integrality and weathering degree of rock-mass，and the integrality and weathering degree of rock mass are also evaluated. This paper provides parameters and scientific basis for the aseismic design of the nuclear power station.

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STUDY ON DISTRIBUTION FEATURE OF FRACTURE TOUGHNESS ON ROCK-CONCRETE INTERFACE

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2004, 23 (13): -2225 doi:
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[PDF 184 KB] (1008)

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Based on available test data and fracture criterion，by using probability fracture mechanics and mathematical statistical method，the distribution feature of fracture toughness，，on rock-concrete interface is analyzed，and a method of defining the least number of specimens of fracture toughness is provided. Weibull distribution or lognormal distribution is often used to analyze lifetime problem，so the two models are preferentially considered in tis paper. The analysis shows that the fracture toughness is of lognormal distribution with degree of confidence ，relative deviation and the least number of specimens of 13. The study results can be used in the probability fracture analysis and construction quality control of rock-concrete interface.

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RESEARCH ON FATIGUE DAMAGE OF CONCRETE UNDER BIAXIAL COMPRESSIVE LOADING USING ULTRASONIC VELOCITY METHOD

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2004, 23 (13): -2230 doi:
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[PDF 567 KB] (1022)

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This paper presents a study on the histories of ultrasonic velocity variations of concrete specimen during biaxial cyclic compressive loading tests. Results show that the attenuation of the transverse ultrasonic velocity follows S-shape line，which can be divided into three phases，lasting about 10%，80% and 10% of the sample life，respectively. The effects of the level of stress on the sample are investigated，too. A damage variable is defined based on the transverse ultrasonic velocity and used to describe the growth law of fatigue damage. The general method to evaluate the fatigue damage of the concrete and residual life of structure is presented.

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RESEARCH ON SAFETY AND DURABILITY OF BOLT AND CABLE-SUPPORTED STRUCTURES

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2004, 23 (13): -2235 doi:
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[PDF 245 KB] (1731)

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The problems about safety and durability of bolt and cable-supported structures are presented. A brief review is made on the existing rupture examples of this kind of structures. The relevant study development at home and abroad on these problems is introduced. Some key problems are pointed out，and suggestions are made on the study methods of service life and protective countermeasures for bolt and cable-supported structures.

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SECOND-ORDER SECOND-MOMENT METHOD FOR STRUCTURAL RELIABILITY
ANALYSIS OF TUNNEL LINING

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2004, 23 (13): -2243 doi:
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[PDF 288 KB] (1113)

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Tunnel lining commonly is curve wall，and the load is complex，so load effect at each section of tunnel lining is not easily obtained. In general，numeric method is adopted to calculate the load effect. In reliability analysis for tunnel lining structure，the simple first-order second-moment method combined with stochastic finite element method is usually employed，but its precision is low. Although there are many methods of higher precision for reliability analysis，most of these methods are complicated or their calculation time is too long. They are not suitable for reliability analysis of tunnel lining structure. Hereby，it is suggested that second-order second-moment method combined with stochastic finite element method should be employed instead，and detailed formula and examples are given. Result shows that this method is of higher precision.

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PROBABILITY METHOD OF ESTIMATING GEOTECHNICAL MATERIAL TEST TIMES

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2004, 23 (13): -2248 doi:
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[PDF 140 KB] (908)

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Test is usually made to estimate the geotechnical material parameters. But the test times are not easy to be determined，because many uncertainties are involved in the test. The probability and statistics theory are used to express the least expected loss and to determine the optimal test times through strict mathematic reasoning. A case study is made to show the availability of the presented method，and some relative problems are discussed.

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ELASTOPLASTIC ANALYSIS ON CONTRACTION OF SPHERICAL CAVITY UNDER DRAINAGE

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2004, 23 (13): -2251 doi:
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[PDF 280 KB] (775)

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The stress and displacement solutions of contraction of spherical cavity under drainage are obtained by neglecting the influence of the elastic deformation in plastic zone. The effects of corresponding parameters are discussed. The relationship between the support pressure and the radius of the elasto plastic boundary is revealed. It is shown that the smaller the radius of cavity is，the smaller the plastic region is for the same depth and the arching effect is more obvious. The deeper the borehole is，the smaller the plastic region is for the same radius. When support pressure is decreased，the plastic region is increased. The maximum displacement occurs at the cavity wall. The dilation angle has an obvious effect on the cavity displacement and little effect nearby the boundary. With the increment of dilation angle，the cavity displacement is increased.

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APPLICATION OF PSEUDO COLOR ENHANCEMENT METHOD TO GEOTECHNICAL CT IMAGE ANALYSIS

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2004, 23 (13): -2257 doi:
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[PDF 409 KB] (2842)

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As a non-destructive and non-invasive technique，CT technique has been successfully used to detect internal fracturing process of soil and rock. In previous geotechnical CT image analysis，CT data are transformed into gray-scale images as usual. However，it is well known that human vision is less sensitive to difference between gray-scale pixels than that between color ones，so the detailed distribution of CT number is not easily recognized based on gray-scale CT images. In order to improve the discriminability，a pseudo color enhancement method based on gray-scale-color transform is used for geotechnical CT image，and some of gray-scale CT images are enhanced using this method. It clearly shows that the enhanced CT images can be more easily discriminated than gray-scale ones.

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ANALYSIS OF RELATIVE STIFFNESS BETWEEN FABRICATED CIRCULAR TUNNEL AND SOFT GROUND

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2004, 23 (13): -2262 doi:
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[PDF 192 KB] (904)

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Considering the interaction and coordinate deformations between flexible tunnel lining and the adjacent soft ground，the concepts of stiffness resisting differential pressure on tunnel and relative stiffness ratio of tunnel and ground are presented. The corresponding theoretical method to calculate this ratio is also set up considering the variation of joint rotating stiffness with the magnitude of stress. As an application of this theory，based on the constructed Shanghai Metro Line No.2，flexibility index of tunnel lining is quantitatively discussed. The result shows that the lining with thickness of 200 mm should be treated as flexible tunnel and the flexibility index is assumed to be 100%. This conclusion has a good agreement with the qualitative result from the valuating criteria of relative flexibility founded by Peck et al in 1972. For the existing Shanghai Metro tunnel lining with thickness of 350 mm，the calculated flexibility index is 69%，which theoretically demonstrates such an argument that the present Shanghai Metro lining is，to some extent，flexible with rigidity.

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TIME-ENERGY ANALYSIS BASED ON WAVELET
TRANSFORM FOR IDENTIFYING REAL DELAY
TIME IN MILLISECOND BLASTING

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2004, 23 (13): -2266 doi:
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[PDF 294 KB] (1075)

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In millisecond blasting，the designed or selected delay time is always different from the real one due to the delay errors of ordinary short delay detonators. The problem influences both the effect and successful implementation of blast. It is significant to identify real time of delay in millisecond blasting. The time-energy density analysis based on the wavelet transform has the character of making the abrupt change of signal energy prominent and can effectually identify the blasting moment of short-delay detonators. Then the real time of delay can be ascertained by analyzing the energy distribution of the monitoring signals in millisecond blasting，and the problem mentioned above can be solved successfully. The effectiveness of the proposed method is verified with time-energy density analysis of vibration signals of millisecond blasting in an underground engineering. The method can be also applied to analyze the attenuation laws of energy for blasting vibration signals during the propagation，blasting mechanism and blasting seismic effects in its entirety.

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MULTI-RESOLUTION WAVELET ANALYSIS ON COMPACTNESS MEASUREMENT OF SOFT SOIL BY INSTANT HAMMERING METHOD

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2004, 23 (13): -2271 doi:
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[PDF 411 KB] (999)

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In the construction of roadbed，it is still an important work to find a fast，nondestructive and precise measurement method for soil compactness. The method for measuring the compactness of soft soil by instant hammering，and the signal analysis method based the wavelet and AR spectrum analysis are put forward. By the analysis of signal measured in lab，the characteristic parameters are picked-up，and some useful conclusion is obtained. The main peak frequency is increased with the dry density under condition of same water content，but decreased with the water content under condition of same dry density. The analysis result shows that the method of instant hammering is feasible for determining compactness of soft soil.

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PREDICTION OF FROST HEAVE BASED ON
FRACTAL INTERPOLATION

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2004, 23 (13): -2276 doi:
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[PDF 1648 KB] (911)

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The simulation curve and test curve of frost heave are analyzed by using the theory of fractal geometry，and it is shown that the curve of frost heave is of self-comparability. At the same time，the function of temperature-time is set in order to obtain the relation rule between frost heave and time. Then，the relation curve of frost heave with time is fitted by using LHIFS and fractal interpolation. Thereby frost heave is predicted. At the same time，the result of imitation is contrasted with that of survey and calculation，which indicates that the result of fitting is stable and accurate. So a new prediction method is offered for frost heave.

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APPLICATION OF LINEAR FROZEN SOIL WALL TO SUPPORT OF FOUNDATION PIT

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2004, 23 (13): -2280 doi:
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[PDF 311 KB] (957)

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Based on the similarity theory and the engineering factors，the equations of similarity rule are deduced on the temperature and deformation of a linear frozen soil wall for protecting deep foundation pit. The simulation design and model tests are made to study the temperature and deformation of frozen soil wall. The results indicate that the temperature distribution of frozen soil wall is approximately linear. It is feasible to use foam plates to keep the low temperature of frozen soil wall. The deformation of frozen wall is composed of rotational，elastic and bigger creep deformations，and it nonlinearly increases with the ground pressure and nonlinearly decreases with wall thickness. There is a power function relationship between wall’s exposing time and the deformation. The design method for frozen soil wall is also discussed. The deformation constraint condition and the concept of effective thickness are put forward for frozen soil wall，and all the factors should be comprehensively considered for the determination of effective thickness of frozen soil wall，such as the temperature distribution，the stability against overturn，the deformation constraint condition and the strength condition of frozen wall for protecting deep foundation pit.

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NUMERICAL SIMULATION ON INTERACTION BETWEEN FROZEN SOIL WALL AND ITS SUPPORT STRUCTURE IN DEEP EXCAVATION

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2004, 23 (13): -2286 doi:
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[PDF 417 KB] (880)

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The study on the interaction laws between the frozen soil wall and its supporting structure is of great importance in the deep excavation. The difficulties in the application of the ground freezing method to deep excavation are presented firstly. The interaction laws between the frozen soil wall and its supporting structure after excavation and during creep period are obtained with numerical simulation elasto plastic and creep models. The results of elasto plastic model，without considering the creep properties of frozen soil，indicate that the release of loading by excavation is the major factor that leads to the deformation of the frozen soil wall and the liner. In this case the distributions of displacements are not closely related to excavation height，and the supporting structure has an appreciable restricting role，which prevents the frozen wall from displacing and rotating freely. However，during the creep period，besides the effect of the excavation，the creep characteristics of frozen soil，the exposed time and height have strong effects on the distributions of the stresses and displacements，which has been shown by the creep models. Therefore，it is suggested that all these factors should be comprehensively taken into consideration in engineering practice.

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STUDY ON RATIONAL STRUCTURE OF RAILWAY TUNNEL
BED UNDER DYNAMIC VIBRATION LOAD

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2004, 23 (13): -2292 doi:
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[PDF 1517 KB] (1172)

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Based on in-situ measurements carried out by the authors at Jinjiayan railway tunnel，a simulated vertical dynamic load of passing trains is put forward. 2D finite element method is adopted to analyze the dynamic responses of tunnels and their surrounding masses to the traffic vibration. In the analyses various structure types，various curvatures，various stiffnesses of the invert and various types of connection of the invert with side wall are considered. The stresses of invert and stress distribution of the surrounding masses under the invert are obtained，and the effect of the structure type of invert on vibration responses is assessed. As a result，a rational structure type of railway tunnel under dynamic vibration load is put forward. The effective measures and rational structure for the railway tunnel bed under dynamic vibration load are that (1) the tunnel invert with the larger ratio of rise to span is recommended，(2) the filling on invert is as thick as possible，(3) a entire rigid structure should consist of invert，filling and road bed with help of concrete of the same strength，(4) the water stocked under the invert must be drained away to avoid rock-soil liquefaction under long-term vibration，and (5) grouting and bolting should be employed to reinforce the surrounding rock masses under invert.

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ANALYTICAL SOLUTION OF HORIZONTAL VIBRATION FOR SINGLE PILE IN DOUBLE-LAYER SOILS CONSIDERING
SHEAR DEFORMATION

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2004, 23 (13): -2298 doi:
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[PDF 276 KB] (1014)

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The beam-on-dynamic-Winkler-foundation (BDWF) model is utilized to determine the horizontal dynamic response of a single pile in double-layer viscoelastic soils. Based on frequency-dependent ‘springs’ and ‘dashpots’，the pile is modeled as a Timoshenko beam considering both bending and shearing and a more rigorous analytical solution of horizontal vibration for a single pile is developed. On the basis of the solution developed here，the influence of many parameters on the dynamic response of pile，such as the ratio of the Young’s modulus of the pile to that of the soil，the ratio of pile length to its diameter，the variation of soil properties and the frequency，is studied. Furthermore，a comparison is also made between the theory here and that based on Euler beam model in two-layered soils. It is found that the theory based on Euler beam gives more errors without considering the parameters given here. Thus，in the analysis on horizontal vibration of pile in layered soils，the more rigorous theory presented herein should be used，otherwise more errors can be brought forward to the analysis result.

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NEW METHOD FOR ESTIMATION OF ULTIMATE BEARING
CAPACITY OF FRICTION PILE

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2004, 23 (13): -2305 doi:
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[PDF 316 KB] (1091)

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Based on the statistical relationships of the number of standard penetration test (SPT) with the standard value of utmost lateral friction ( ) and standard value of utmost tip resistance ( ) of piles，and SPT number with shear wave velocity ( )，the interrelated models of with and in the soil around pile is established. Using the technique of transient surface wave test，the shear wave velocity in different depth below the ground can be obtained rapidly. So，a new method of transient surface wave test technique is put forward to predict the bearing capacity of friction pile. Model pile essay and practical engineering application indicate that this method has favorable application foreground.