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2003, 22 (12): -0 doi:
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NUMERICAL SIMULATION ON FAILURE MECHANISM OF ROCK SLOPE BY STRENGTH REDUCTION FEM

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2003, 22 (12): -1943 doi:
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[PDF 700 KB] (1499)

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The stability of rock slope is mainly determined by its discontinuity and rock bridge. However，the failure mechanism of discontinuity and rock bridge has not been studied comprehensively. In this paper，the stability analysis of jointed rock slope is carried out by shear strength reduction finite element method. The elastic-perfectly plastic material is adapted in the finite element method. With the strength reduction，the nonlinear FEM model of jointed rock slope reaches instability，and the numerical non-convergence occurs simultaneously. The safety factor is then obtained by strength reduction algorithm. At the same time the critical failure surface and overall failure progress are found automatically. The numerical convergence or non-convergence is related to the yield criterion. Comparison is made of several yield criteria in common use. The Mohr-Coulomb criterion is undoubtedly the best-known criterion. But its yield surface is an irregular hexagonal cone in principal stress space. It brings difficulty to numerical analysis. For convenience the Mohr-Coulomb criterion is replaced by Mohr-Coulomb equivalent area circle yield criterion. Through a series of case studies，it is found that the safety factor obtained by strength reduction FEM with Mohr-Coulomb equivalent area circle criterion is fairly close to the result of traditional limit equilibrium method (Spencer’s method). The result shows that the discontinuity coalescence pattern is influenced by its strength，length，location，and obliquity. The failure occurs 'naturally' through the zone in which the shear strength of rock is insufficient to resist the shear stresses. Through a series of case studies，the applicability of the proposed method is clearly exhibited. This study presents a new approach for stability analysis of jointed rock slope，and it is especially available to the complicated geological condition and supported slope.

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REBUILT SLICE METHOD FOR SLOPE STABILITY ANALYSIS

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2003, 22 (12): -1953 doi:
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[PDF 290 KB] (997)

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In this paper an attempt is made to present a rebuilt slice method，which is strict in conformity with the plastic limit analysis theory，and is simultaneously able to be related with the traditional slice-method. The slice method is reduced into a large-scale extremum problem in static permission field，and the results of the extremum problem solved by the improved annealing simulation algorithm show that the convergence of solution is very good. The comparison with the Bishop method also shows good coincidence between these tow methods.

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3D STABILITY ANALYSIS OF THREE GORGES DAM FOUNDATION NEAR LEFT ABUTMENT

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2003, 22 (12): -1960 doi:
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[PDF 356 KB] (954)

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Because there exists a set of long persistent joints in the bed rock near the left abutment of the Three Gorges dam，a general attention is paied to the problem of stability. Most of the former study employed 2D analysis methods. As this issue is related to an extremely important dam，the 3D upper-bound method is used to evaluate the factors of safety and find how much additional help is needed if 3D effect is accounted for. The presented method makes feature of its rigorous theoretical background and simple numerical procedures，and it is an extension of the Sarma¢s 2D method. The study result shows that the 3D safety factor is much larger than 2D one.

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STUDY ON INTELLIGENT FORECAST AND CONTROL OF CONSTRUCTION DEFORMATION OF DEEP FOUNDATION PIT OF NORTH ANCHORAGE OF RUNYANG BRIDGE(I)

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2003, 22 (12): -1966 doi:
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[PDF 205 KB] (1040)

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On the basis of time series analysis of diaphragm wall deformation in deep pit system，a MATLAB system-based ANN multi-step deformation forecast model is developed. The deformation corresponding to multi-steps of excavation can be predicted with this model at a time，and the construction parameters can be adjusted in time，so that the diaphragm wall deformation can be controlled. The deep foundation pit of north anchorage of Runyang Bridge is taken as a case example to make study on intelligent forecast and control of construction deformation，and it is showed that the results of prediction agree well with the data of in-situ measurement.

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COMPREHENSIVE FUZZY EVALUATION MODEL FOR SLOPE SAFETY
BASED ON EXTERNAL DEFORMATION OBSERVATION

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2003, 22 (12): -1971 doi:
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With the progress of excavation，the increment of engineering load and the change of environmental factors，soil or rockmass deforms inevitably，and sometimes even instability failure occurs. The purpose of stability monitoring is to predict and find the symptom of instability failure. Generally，the observed external deformation is composed of elastic and plastic deformation of slope rock，shear displacement along the sliding plane and observation error. The shear displacement is important for the evaluation of slope stability，but it is difficult to separate the shear displacement from the measured data. So it is not easy to evaluate and predict stability of rocky slope by external deformation which is small before slope fails. After expounding the external deformation characters of rocky slope and the suspension bridge foundation，the following evaluation principles for the safety of engineering slope are suggested based on the external deformation monitoring：nonsingle-point，conformability，progression，rationality，non-causation and visualization. Then the comprehensive evaluation model is established by means of fuzzy mathematics with multiple factors considered. Based on the boundary conditions and the structure characters of foundation and slope，the zoning safety evaluation on the south bank slope of Jiangyin Yangtze Bridge is given as an example to test this model.

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DISPLACEMENT VECTOR ANGLE OF COLLUVIAL SLOPE
AND ITS SIGNIFICANCE

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2003, 22 (12): -1976 doi:
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[PDF 229 KB] (986)

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Based on interpretation of the monitoring data of actual displacement which resulted from the landslides in Xintan，it is shown that the stability of whole homogeneous colluvial slope is closely correlated with two parameters，velocity of surface displacement and angle of surface vector. The stability trend can be described and evaluated by both the displacement velocity and the vector angle. The displacement vector angle，especially，for which there is no substitute，is an important parameter serving as an explicit criterion for the stability of slope，and hence it is significant for prediction of landslides. So systematical space-time analysis is made on the features of vector angles of surface displacement. From this analysis，the distribution laws of space-time and the characteristics of the displacement vector angles are deduced. On the basis of these results and using the principles of statistics，thd double-parameter criterion for forecasting the stability of the colluvial slopes is established. According to the double-parameter criterion，calculation and evaluation of stability are made on Xintan slope by monitoring data on F-series of points on the slope. The prediction results are coincided with the actual time and the laws of the landslide，which demonstrates that the double-parameter criterion is of satisfactory precision and practicality in prediction of landslides.

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PREDICTION OF LANDSLIDE BASED ON CHAOS AND
NEURAL NETWORKS

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2003, 22 (12): -1984 doi:
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[PDF 271 KB] (1089)

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According to the nonlinear dynamical characteristics of landslide，with the prediction algorithms based on chaos and neural network，the embedding dimension is determined through data experiment，and the model of the chaotic process of landslide is set up. The experiment shows that this method can provide a satisfying result in the prediction of displacement monitoring data obtained in Maoping landslide of Qingjiang River. This method can avoid the difficulty to build the precise dynamics equations and determine the attractor¢s dimension，and is of practicability in the prediction of landslide.

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MECHANISM OF TIME-DEPENDENT DEFORMATION
AND FAILURE OF MUDSTONE SLOPE OF EXPRESS HIGHWAY

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2003, 22 (12): -1988 doi:
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[PDF 355 KB] (1064)

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In the construction of express highways in mountainous areas in west China，landslide or failure of the mudstone slopes often occur. On the basis of large deformation theory，with the completely nonlinear transient dynamical analysis，the time-dependent deformation process is studied considering pore water pressure produced by downpour before and after excavation and the dissipation of pore pressure. It is revealed that the leading factor affecting slope stability is pore water pressure，which provides a basis for reinforcement measures.

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DETERMINATION OF DYNAMIC STRENGTH PARAMETERS OF GEOMATERIALS BASED ON UNIFIED STRENGTH THEORY

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2003, 22 (12): -1994 doi:
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[PDF 288 KB] (965)

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Based on the Yu Maohong's unified strength theory，a new method is proposed to study dynamic strength parameters of geomaterials and strength theory under the complex stress state. Considering the property of repeated loads and the effect of intermediate principal stress，the concept of dynamic limit equilibrium under unified strength is put forward by coupling the dynamic strain with the theory of limit equilibrium，and then the equations that can determine the effective strength index and are obtained. A simple method is also advanced to determine the effective strength index and which takes account of the concept of deviator stress，effective consolidation pressure and the dynamic equilibrium line of unified strength theory. This method can be applied to sandy soils，silty soils and deposit soft rock.

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TESTING STUDY ON LANDSLIDE OF SATURATED SAND SLOPE SANDWICHED WITH LOW-PERMEABILITY LAYER

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2003, 22 (12): -2001 doi:
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The pattern of uneven seepage-induced landslide in the saturated sand slope sandwiched with a low-permeability layer under impact loading is explored by means of simulation tests. Especially，the relations between the development of landslide and the emergence of water layer and drainage pathway are described. Some major influencing factors，such as intensity of loading，thickness of fine sand layer，angle of slope，and densification degree of sand，are also examined. The testing results show that，under a certain impact loading，the structure of the sand sample undergoes irrecoverable deformation，the pore water pressure is built up immediately，and the sand sample is liquefied. The pore water is driven quickly because the permeability of the initial liquefied sand is larger than that of the origin sand，and that caused simultaneously settlement of the sand. Given that the drainage in the sand slope is along the maximum water pressure gradient (i.e. the direction perpendicular to the slope surface)，the sudden settlement of the surface of sand slope is observed.
The seepage is uneven in the sand sample because of the presence of the low-permeability layer(the thin fine sand layer). During the upward seepage process of the pore water in the liquefied sand，the pore water accumulates underneath the fine sand layer and thus the shear strength at that location becomes lower than that of neighboring region，providing that the liquefied sand still holds certain strength value. When the pore water accumulates and the shear strength beneath the fine sand layer is lost gradually，the sliding of the sand slope is initiated under the combining action of gravity and pore water pressure.
The shear resistance and the sliding potential are determined by the sand sample and related to the location. The slope surface is separated into two parts because the lower reach of the sand slope undergoes a larger displacement relatively. The slide of the slope is damped，because the footing of the slope is elevated and the angle of the slope becomes smaller. A thin pore water seam can be observed just underneath the thin fine sand layer from the lateral side of experimental setup. The water flows along the water seam to form a drainage pathway and spills out at the fractured position of the upper surface of the slope.
The whole process of the liquefaction，drainage，settlement，and sliding is a coupling one in which some fine sand may flush away and accumulate at the location with lower initial permeability. Under a certain intensive impact loading，the sand slope will experience the process described above. Therefore，the presence of the thin fine sand layer of lower-permeability in the sand slope is one of the important factors to cause this kind of landslide.

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NUMERICAL SIMULATION ON TIME-SPACE EFFECTS OF PLANE FROZEN SOIL WALL RETAINING DEEP-FOUNDATION PIT

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2003, 22 (12): -2006 doi:
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Aiming at the existing problem of structural calculation in deep foundation pit supported by plane frozen soil wall，the numerical simulation of 3D FEM is presented. In the calculating model，it is considered that the frozen soil wall is made up of non-homogeneous visco-elasto-plastic media which follows the Mises yield criterion，and the ambient soil is elastic-plastic medium which obeys the Drucker-Prager yield criterion. At the same time，the interaction between plane frozen soil wall and ambient soil and the effect of step-by-step excavation are considered. Taking the deep foundation pit of original experimental segment in Nanjing subway as the prototype，the numerical simulation of time-space effect of plane frozen soil wall is performed by 3D FEM. The distribution rules are obtained of displacement and stress in the plane frozen soil wall and ambient soil during and after the excavation. The calculating results provide basis for design of deep-foundation pit supported by plane frozen soil wall，and indicate that creep property of frozen soil wall should be paid much attention to in actual engineering application. To optimize design parameter of plane frozen soil wall better，the calculating model is set up according to orthogonal design graph. By changing the thickness of frozen wall，freezing brine temperature and span of pit，their effects on stability of deep foundation pit are analyzed，and the regression equations of maximum horizontal displacements of frozen soil wall and settlement of ambient soil are obtained. Finally，a test model is analyzed and calculated by this procedure，and the calculation results are in good agreement with the test values. So it shows that it is reasonable and creditable to analyze the time-space effects of plane frozen soil wall by 3D FEM.

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STABLE OR UNSTABLE CRACK GROWTHS IN THIN ROCK PLATE UNDER COMPRESSION FOR PREDICTING BUCKLING ROCKBURST

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2003, 22 (12): -2011 doi:
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[PDF 212 KB] (1293)

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Underground cavern opening can cause the surrounding rock tangential compressive stress to raise rapidly. Such high compressive stress increase can result in some original pre-existing cracks growing parallelly to the free surface of the remaining rock. This paper presents a model of crack stable or unstable propagation under compressive stress in thin layers that are separated from the main rock mass due to crack growth. Based on this analysis of flat plate buckling，a rock burst mechanism is presented. Immediate and delayed rock burst mechanism are proposed to explain time dependency in brittle rock sub-critical crack growth under compression. Influence of free surface on the surface-parallel crack growth is also discussed.

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DAMAGE EVOLUTION OF UNIAXIALLY COMPRESSED HONG KONG GRANITE

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2003, 22 (12): -2019 doi:
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[PDF 385 KB] (1448)

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An investigation is reported on the characteristics of progressive failure of Hong Kong granite. Uniaxial compression tests are performed on a number of Hong Kong granite specimens with the MTS 815.04 testing machine. Acoustic emission signals are recorded to trace the evolution of damages. Parametric studies on the effect of grain size are attempted. The results show that the increase in grain size will reduce the brittleness during failure. In addition，discussion is extended to the grain size effect on the stress thresholds of crack closure，crack initiation and crack damage. The RFPA2D code is also used to observe the failure characteristics of brittle rocks such as granite. Microscopic tensile failure is dominant in the ultimate failure of all the uniaxially compressed models. The crack initiation threshold is also determined by the numerical approach. The failure of coarse-grained models seems more ductile.

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DEFORMATION AND FRACTURE FEATURES
OF UNLOADED ROCK MASS

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2003, 22 (12): -2028 doi:
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[PDF 189 KB] (1421)

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On the basis of unloading tests of rock sample，the deformation and fracture features of unloaded rock mass are studied in conjunction with fracture systems of some large excavation project. Research shows that the deformation of unloaded rock is of intense dilatancy in unloading direction，the fracture is characterized by tensile one，and there are tensile-shear fractures and shear fractures. The deformation and fracture feature of unloaded rock mass is dominated by the rock mass structure，and deformation and failure in unloaded rock is prone to take place compared with those in rock. Especially，the fracture system，is controlled by the rock mass structure.

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STUDY ON SIZE EFFECT OF UNLOADED ROCK MASS

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2003, 22 (12): -2032 doi:
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[PDF 270 KB] (1163)

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According to the characteristics of high slope rock mass of the permanent ship-lock in the Three Gorges Project，some typical rock mass is chosen for physical simulation. The size of unloaded specimen is 0.25 m×0.25 m×0.25 m，and the corresponding actual sizes are 0.75 m×0.75 m×0.75 m，2.25 m×2.25 m×2.25 m，6.75 m×6.75 m×6.75 m，and 20.25 m×20.25 m×20.25 m. The problems of size effect of unloaded rock mass，i.e. stress-strain relation，the compressive strength，the deformation modulus (compressive and tensile)，the Poisson’s ratio，and the anisotropic characteristics，are studied. Some significant conclusions are put forward，and the mechanical parameters are suggested to consider size effect.

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CONSTITUTIVE RELATIONS OF UNSATURATED SEEPAGE
FLOW IN FRACTURED ROCK MASSES

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2003, 22 (12): -2037 doi:
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[PDF 246 KB] (1196)

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Based on the numerical simulation of two dimensional unsaturated flow in a single fracture with the continuum approach，an evaluation on the application of Van Genuchten(VG) model and Brooks-Corey(BC) model in fractured rock mass is presented and an improved constitutive relation model is obtained by mainly comparing VG and BC models with the simulated and measured results. Although VG model can reasonably well match the simulated water retention curves，both VG and BC models underestimate relative permeability. Simulation results indicate that an improved model，derived from combination of Brooks-Corey relative permeability-saturation relation and the VG capillary pressure-saturation relation，can generally describe the characteristics of unsaturated flow in fractured rock masses，but the effectiveness of the model in some aspects needs further research，such as the relation curves for higher saturation condition.

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STUDY ON MATHEMATICAL MODEL OF THREE DIMENSIONAL HYDRAULIC FRACTURING

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2003, 22 (12): -2042 doi:
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[PDF 266 KB] (2027)

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According to the theory of fluid mechanics in porous media，rock mechanics，heat transferring and fracture mechanics，the mathematic model is established to characterize 3D hydraulic fracturing. Rheology of fracturing fluid，process of supporting reagent transferring，change of thermal field and coupling effect among different procedures are considered in this model. The method and numerical solution to compute crack expansion are also given. In the end，a case study is shown to verify the model.

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NEW BLASTING TECHNOLOGY——BILATERAL CUMULATIVE TENSILE EXPLOSION

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2003, 22 (12): -2047 doi:
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Bilateral cumulative tensile explosion，a new controll blasting technology of cumulative explosion，is put forward and defined，which aims at resolving the problems existing in conventional blasting，smooth blasting，present control blasting and the status of complex outline shaping blasting in rock masses with high uniaxial compressive strength. In application，the charge is put into a special set with cumulative effect in two designed directions，and then the charged set is put into the shot hole. After being detonated，even compressive stress and concentrated tensile stress from explosion are produced in non-controlled and controlled directions，respectively，and then the stresses act on corresponding wall of the shot hole. As a result，crannies are initiated and propagated and rock mass are fractured in controlled direction. The characteristics of new blasting technology，matching sets，explosion mechanism and mechanics models of explosion are detailedly introduced in the paper. On the basis of field experiments of explosion of single borehole and multi-boreholes， the technology is applied to blast rock window and bench in some special large caverns. The satisfactory blasting effects have been achieved. The application results show that the technology is practicable and effective to complex outline shaping blasting of rock mass with high uniaxial compressive strength. The technology shows a bright future of widespread applications.

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DESIGN APPROACH FOR EXCAVATION BLASTING NEAR
CONTOUR OF ROCK SLOPE

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2003, 22 (12): -2052 doi:
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Basen on the criteria of the peak particle velocity(PPV) for blast-induced damage，the design approach for excavation blasting near contour of rock slope is discussed. A mathematic error existed in the equation to calculate PPV proposed by Holmberg and Persson is modified，then a new method which is both theoretically reasonable and easy to use is proposed to determine PPV. Finally，with the practical case of the rock slope excavation of the permanent ship locks at Three Gorges Project as an example，the detailed application of the modified approach is introduced，and rationality evaluation of the practical design parameters adopted at Three Gorges Project is also performed.

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BLAST-INDUCED CRACK DEVELOPING VELOCITY BASED ON
WAVELET IMAGE PROCESSING

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2003, 22 (12): -2057 doi:
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[PDF 249 KB] (1297)

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Slow-motion photograph is used to study the rule of blast-induced crack developing. But the images of slow-motion are blurred because of some reasons，such as the blasting smog，which makes a bad influence on the study of crack developing. By use of computer image processing technique and wavelet transform theory，and VC++ program and MATLAB software to handle the slow-motion pictures of explosion，the crack developing velocity of marble under explosion is given based on processed images，which is helpful to the furture study of blast-induced crash mechanism of rock.

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STUDY ON TRAIN-INDUCED VIBRATION AND ITS INFLUENCE
ON KARST COLLAPSE

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2003, 22 (12): -2062 doi:
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[PDF 231 KB] (956)

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From the actual measurement of the vibration wave induced from train with the geological condition of Karst collapse nearby railway，the vibration wave process and damping features of the wave are analyzed and discussed. The damping rule of vibration along railway is obtained and calculation is made for damping coefficient(0.2/m) in the hard plastic clay. From the distribution of damping coefficient，the safe depth of soil layer is presented for railway in given condition，which is about 7 meters. The damping coefficient may be impacted by precipitation，temperature，and the property of soil layer. In the research，the field measurement of vibration process from train is made，and the wave curve shows obviously a pulse feature in the process.

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RESPONSE OF SINGLE PILE EMBEDDED IN TRANSVERSELY ISOTROPIC STRATIFIED STRATA TO INCIDENT SH WAVES

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2003, 22 (12): -2067 doi:
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[PDF 221 KB] (706)

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A model of transversely isotropic stratified strata is used to simulate the soil layers. At the bottom of the strata，dampers are used to absorb the vibration energy. A pile is embedded in this strata. The method for calculation of the dynamic impedance of single pile is developed. Combining the impedance and the response of the strata to incident SH waves，the response of single pile is obtained. The numerical examples indicate that the maximal moment of pile may cause the pile to fail，and more attention should be paid to the phenomena.

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PRESENT SITUATION AND FUTURE PROSPECT OF APPLICATION OF TUNNELING MACHINE TO CHINESE UNDERGROUND ENGINEERING CONSTRUCTION

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2003, 22 (12): -2071 doi:
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The application of tunneling machine to Chinese underground engineering construction is outlined，and its future prospect is forecasted in the light of the requirements for Chinese underground engineering construction in the 21st century. Further suggestion is put forward on the effective use of tunneling machine.

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STRENGTH AND DEFORMATION OF SPECIMEN FOR DIFFERENT COAL BLOCKS AND REGRESSION METHOD OF STRENGTH CRITERION

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2003, 22 (12): -2081 doi:
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[PDF 177 KB] (1083)

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Coulomb strength criterion means that the maximum axial stress of a given specimen increases with confining pressure linearly under the pseudo-triaxial compression. The strength of rock specimen is gotten after its destroy，so one specimen can give the strength under one confining pressure only. Unlike the local flaws in sedimentary，the fissures and weakness in coal are distributive，which influence both deformation and strength. Specimens form various coal blocks are of great difference in mechanics property. The uniaxial strength is 5.3～10.4 MPa and Young¢s modulus is 2.36～3.17 GPa for specimens from Block A，strength 9.8～35.0 MPa and Young¢s modulus 3.08～4.64 GPa for specimens from Block B，strength 5.9～20.7 MPa and Young¢s modulus 2.34～4.55 GPa for specimens from Block E，respectively. The strength and Young¢s modulus of specimens compressed uniaxially are of great dispersion，but there is a good correlation between them. Fissures in coal specimen compressed under confining pressure will close and axial stress is supported by the friction，which results in the decrement of dispersion of strength and Young¢s modulus. The strengths of specimens from different coal blocks are different，but the coefficients of influence of confining pressure on the triaxial strength or the internal friction coefficients are the same for three coal blocks. The internal friction coefficient is a material parameter and the cohesion is a strength property of coal block. So all the strengths of different coal blocks，no matter how many specimens are made，can be regressed jointly，and the strength property of coal blocks can be known as well. The strength criterion can be decided from various blocks.

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ACOUSTIC RESPONSES TO ROCK CORE UNLOADING-DISTURBANCE AND UNLOADING-SENSITIVE ROCK MASS

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2003, 22 (12): -2086 doi:
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[PDF 239 KB] (931)

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Ultrasonic testing is one of the most frequently used measurements in geotechnical rock mass evaluation. The square of the ratio of longitudinal wave (P-wave) velocity of rock mass to that of rock block is defined as intactness index of rock mass. As we know，the P-wave velocity of in-situ rock mass is believed to be lower than that of relevant rock block. The more broken the rock mass is，the lower its P-wave velocity is than that of rock block. However，according to the result of ultrasonic testing carried out at Runyang Highway Bridge，it is surprised to find that most P-wave velocities of rock mass are higher than that of rock block. Many different measurements are applied in the comparative research，which is based on hundreds of rock cores collected from over 40 boreholes in the bed rock of the Bridge site，and the reliability and causes of the results are analyzed. The concepts of rock core unloading disturbance and unloading-sensitive rock mass are then put forward，with relevant engineering countermeasures.

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APPLICATION OF HIGH-FREQUENCE ULTRASONIC WAVE TECHNOLOGY TO TECTONO-PETROLOGY——TAKING CAOHU AREA OF SOUTH PART OF TANCHENG-LUJIANG FAULT BELT AS EXAMPLE

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2003, 22 (12): -2093 doi:
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[PDF 229 KB] (984)

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A new method using high-frequency ultrasonic wave technique to the study of structural geology is presented. The relationship between wave velocity and stress in rocks is discussed，and the state of stress distribution in the core parts of anti-cline is presented. The study results show that the ultrasonic wave technology is a possible tool for the study of tectono-petrology. The distributions of wave velocity have close relation to that of stress quality in the deformed rocks. The stress distributions in Fenghuangshan anti-cline obtained by wave velocity are of the same rule with the theoretic deduction. With the ultrasonic wave technique，the distributions of the stress state and the strongest locations can be easily and accurately determined，which is very helpful to the study of tectono-petrology as well as the practice of engineering geology. Comparing with the other methods of studying tectono-petrology，the ultrasonic wave technique is of merit of simple control and high accuracy.

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BEARING BEHAVIOR OF LARGE-DIAMETER ROCK-SOCKET PILES

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2003, 22 (12): -2099 doi:
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[PDF 231 KB] (1249)

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Through simultaneous observation of pile-cap settlement，pile-end resistance and axial stress distribution in large-diameter rock-socket pile under multi-storied building construction，some new practical testing data are presented. Based on these data，the characteristics are analyzed of large-diameter rock-socket pile in working conditions，including pile cap settlement，distribution and exertion of pile-skin and pile-end resistance，selection of rock-socket depth，and the effect of pile end enlargement on pile-skin resistance and pile-end resistance.

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DISCUSSION ON‘SIZE EFFECT ANALYSIS ON STRAIN SOFTENING OF QUASI-BRITTLE MATERIALS CONSIDERING STRAIN GRADIENT EFFECT’

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2003, 22 (12): -2104 doi:
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ANSWER TO PAN YUE¢S DISCUSSION

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2003, 22 (12): -2107 doi:
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[PDF 183 KB] (913)

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