bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization Analysis of Position and the Shape of the Pre-Setting Hole on Cast- In Situ Box Girder Roof
Authors: Cheng Hai Gen , Wang Yan , Xie Li
Published: May 2011

By analyzing concrete crack on the roof caused by the pre-setting hole during the construction process of the pre-stressed concrete cast-in-situ box girder bridge, this paper, which uses segment integral analysis method by ANSYS finite element program, primarily takes into account different hole position and shapes. The result shows that different position and the shape of the pre-setting hole can be seemed as decisive factors in influencing stress near the hole. It can be concluded as: the pre-setting hole should set as far as possible from pre-stressed passageway and the pre-stressed rebar first, then the shapes of hole should use circular or take corner cut polygon. Ultimately, under the premise of normal used construction, it is considerable to strive as much as possible in narrowing down the dimension of the pre-setting hole.
Experimental Study on Mechanical Characteristics of CSG Materials
Authors: Zou De Gao , Li Dong Qing , Xu Bin , Kong Xian Jing
Published: May 2011

Cemented sand and gravel (CSG) is a new type of dam materials. It not only can reduce the waste of resources and environmental pollution, but has the merits of both gravel and concrete. In this study, Cemented sand and gravel specimens with three cement ratios were compacted at optimum water content and cured for 14 days. Based on the consolidated drained shear triaxial tests, the mechanical properties of different proportion of CSG are studied on shear failure mode, stress-strain relationship, shear strength. Research results showed that, with the increasing of the content of cement, the peak and residual strength of CSG were improved, but the failure strains were decreased. In addition, CSG material behaves distinctly softening.
Dynamic Shear Modulus and Damping Ratio of Waste Granular Rubber and Cement Soil Mixtures
Authors: Wang Zhao Yu , Mei Guo Xiong , Yu Xin Bao
Published: May 2011

In this study a resonant column apparatus was used to obtain the shear modulus and damping ratio of the waste granular rubber and cement soil mixtures. Specimens were tested for different rubber contents and confining pressures. Experiments show that with the rubber increased, the damping ratio of the rubber and cement soil mixtures increases, dynamic modulus decreases. When the confining pressure increases, the shear modulus of rubber and cement soil mixtures increase gradualy, damping ratio increase slightly.
Passive Pile Calculation Model and its Reasonable Distance of Piles
Authors: Li Bing Lei , Gao Yong Tao , Wu Shun Chuan
Published: May 2011

The traditional method of calculating soil arch effect was described Firstly, and the inadequacy of traditional methods was analyzed. On the basis of their predecessors, the rectangular cross section of a rational spacing between passive pile was mainly discussed. Based on the mechanical properties of soil between anti-slide piles analysis, a pile of soil conditions of static equilibrium, cross-section strength of the section of the conditions and strength condition of the arch to common control methods to determine the critical pile space were put forward.Relatively reasonable a spacing formula for calculating pile spacing has been obtained. Comparing with rational pile space formula obtained and the traditional formula for the actual project data, the results indicate that, for the cross-section 2.5mx2.5m the pile, formula by rational pile space the calculated results and the calculation method has been compared and analyzed the results, when the landslide thrust 47kN/m2.According to rational pile space formula the results calculated by the situation more in line with the actual project, it is of significance to practical engineering design of anti-slide pile, and there is a greater using and reference value for the similar project via the methods used and the conclusion.
Study on Secondary Consolidation Behavior of Soft-Clay Sediment from Lakes in Yinchuan
Authors: Wang Zhi Bin , Cui Zi Zhi , Zao Shao Xiang
Published: May 2011

There are many soft-clay sediment foundations in Yinchuan area, most of which are made of soft-clay silt from lakes. Its secondary consolidation deformation occupies a large proportion of its total deformation, and displays a greater volume of settlement after work completion, which seriously influence the normal use of buildings. The orthogonal experiments are designed to study the influence of factors such as current stress, dry density and OCR on the secondary consolidation behavior of soft-clay sediment of lake in Yinchuan. The regulation and mechanism of secondary consolidation is revealed. Some useful conclusions are reached to provide reference for projects design and construction.
Research on Distribution Rule of Geostress in Deep Rock in Chinese Mainland
Authors: Li Xin Ping , Wang Bin
Published: May 2011

Based on the research of the conception of “deep stratum” and “deep engineering”, through collecting about 600 groups of the measured geostress data in deep rocks of China mainland, the features of the geostress in deep rocks are elementarily analysed referring the analysis method of Hoek and Brown. The distribution rules of the vertical stress, the maximum and the minimum horizontal principal stresses with depth in deep stratum are analysed, and trend of the lateral pressure coefficient with depth is also discussed.
Experimental Study of Mechanism of Rock Breakage with High-Pressure Cavitating Water Jets
Authors: Ge Zhao Long , Lu Yi Yu , Tang Ji Ren , Hu Ke , Zhang Wen Feng
Published: May 2011

To explore the relationship among the erosion ability of high-pressure cavitating water jets, hydraulic parameters and rock nature with a series of experiments relating to the efficiency of rock-breaking with cavitating water jets for different porosity of rock under different confining pressures and pump pressures. The results show that the erosion efficiency (erosion mass and erosion depth) of cavitating water jets is fitted a conic curve with pump pressure and confining pressure. It increases with the pump pressure increases while decreases with the confining pressure increases; the length of the bubble cloud decreases with the confining pressure increase and the length increases with the pump pressure increase, which is accorded with cubic curve. The bubble cloud length influences the rock-breaking efficiency by deciding the valid stand-off distance directly. Under the experimental condition, the cavitation happens once the pump pressure reaches 7MPa, and the cavitating water jets can crushing the sandstones which the uniaxial compressive strength is 96MPa. On the other hand, the porosity of rock is another main factor of rock breakage with high pressure cavitating water jets. The higher the porosity of rock is, the easier the rock can be broken.
Field Investigation of Influences of Load on Pile Top on Negative Skin Friction Behaviors
Authors: Xia Li Nong , Miao Yun Dong , Li Shun , Tong Xin
Published: May 2011

In order to study influences of applied load on pile top on the negative skin friction behaviors of piles, field investigations of negative skin friction behaviors of three identical piles with different loads on pile top are made in the same site. Test results show that applied load on pile top affects negative skin friction behaviors evidently. Additional settlement of pile induced by negative skin friction becomes larger, negative skin friction induced by the settlement of soil surrounding the pile becomes smaller with the increase of load on pile top. Dragload induced by negative skin friction decreases and position of neutral point in pile moves up while applied load on pile top increases. While there is no applied load on pile top, additional settlement induced by negative skin friction is minimum, dragload induced by negative skin friction is maximum and the neutral point is the farthest from the top of piles. The field investigation results may be useful to the further research for negative skin friction behaviors of pile.
Experimental and Theoretical Study of Air-Entraining Concrete under Biaxial Compression after Freezing-Thawing Cycle
Authors: Yao Jia Wei , Song Yu Pu , Gao Ling Xia
Published: May 2011

Mechanical properties experiments of air-entraining concrete after suffered to 0, 100, 200, 300 and 400 freezing-thawing cycles were performed. The experiment method, contents and result of strength and deformation of air-entraining after freezing-thawing cycle under biaxial compression were also introduced. The relationship between the strain corresponding to peak stress and cycle of freezing-thawing as well as the relationship between compressive strength and cycle of freezing-thawing were analyzed. The failure criterion of air-entraining concrete under biaxial compression was established.
Influence of some Factors on the Behavior of Pile-anchor Retaining Structure for Permanent Supporting Foundation Pit
Authors: Zhang Huai Wen , Liu Jun , Zhang Nan Nan , Gao Quan Chen
Published: May 2011

Considering the various loads combination and durability,pile’s diameter,embedded depth,anchor’s rod, anchorage length need to be strengthened in the permanent supporting foundation engineering.Based on Chengdu Museum foundation project, the influencing factors such as pile’s diameter,embedded depth,anchor’s pretentioned force are discussed.With comparasion of calculated data and monitoring data, this paper generalized influence of pile diameter, embedded depth, anchor pretensioned force on permanent pars mechanics properties.
A Study on the Impact of Structure Plane on Unloading Rock Mass Deformation
Authors: Wang Fei , Liang Xu Li , Du Jian Po , Qi Jian Feng
Published: May 2011

The rock mass deformation properties of unloading is very different from loading.The physical and mechanical properties of structural plane can bring a very great influence to rock’s unloading behavior. The lower the strength parameter of joint plane and the greater the angle of joint, the lower the unloading modulus of deformation. The greater the connectivity of joint,the faster the unloading modulus of deformation descend. In any case unloading amount is near linear relation with descend amount of unloading deformation modulus.
Study on Influence of Geotechnical Grille Characteristic on Mechanics Properties of Reinforced Sand-Gravel
Authors: Xu Bin , Zou De Gao , Gong Tao , Kong Xian Jing , Bi Jing
Published: May 2011

A series of large scale consolidated drained shear triaxial tests were performed on geotechnical grille reinforced sand-gravel specimens, the aim was to study influence of elongation and strength characteristic of geotechnical grille on initial modulus, peak strength, residual strength, brittleness index, volumetric strain and shear strength of reinforced sand-gravel. The results show that: the elongation of geotechnical grille used in the sand-gravel specimens has great influence on residual strength, brittleness index and cohesion of reinforced sand-gravel, but the initial modulus, peak strength and volumetric strain are affected slightly.
Study on Character of Triaxial Extension Strength of Compacted Clay
Authors: Liu Jun Xin , Chen Zhong Fu , Xu Wei Fang
Published: May 2011

For soils, failure occurs with lower deviatoric stress under the same pressure (the first invariant of stress tensor) in TXE compared with the strength of the triaxial compression, which is indicated that the strength of soils strongly depends on the third invariant of stress deviator; Although in the traditional Mohr-Coulomb criterion it can be reflected in difference of strength between triaxial extension and compression under the same pressure, it’s nothing to do with the pressure for the strength ratio between triaxial extension and compression. By TXC and TXE, changes of deviatoric stress and the ratio with the pressure were studied
Discussion of Feasibility of Producing Soil Stabilizer with Industrial Waste
Authors: Deng Xiao Xuan , Dai Lei , Li Zhan Guo , Huang Xin
Published: May 2011

The feasibility of utilizing industrial waste to produce soil stabilizer with high added value is discussed from technical effect, economic benefit and production and management mode. Principle of design of the stabilizer with industrial waste is offered based on the properties of stabilized soil structure formation and its special demand on stabilizer components; the examples of the stabilizer composition are presented, and the performance/cost ratio of the stabilizers are compared with that of cement. Reasonable production and management mode for industrially producing the stabilizer with industrial waste is discussed also. It is suggested that as long as appropriate industrial waste is selected intentionally to meet the special demand on the stabilizer composition needed to form stabilized soil structure, the soil stabilizer with high performance/cost ratio can be obtained. It is advised that the stabilizer should be designed individually according to the properties of the soil to be stabilized, the stabilizer should be produced with the production mode of mixing multi-components and adopt the management pattern of incorporating designing, production and sale.
Research on the Gas Migration Regularity of Municipal Solid Waste Landfill in the Solid-Liquid-Gas-Heat Interaction
Authors: Liu Xiao Li , Si Wen Jing , Zhu Chun Ying
Published: May 2011

With the establishment of large municipal solid waste landfills, the interaction of geological environment in landfill (seepage field, stress field and temperature field, etc.) has not to be ignored. The multi-field coupling problem of the municipal solid waste landfill is getting attention. But at present the study mainly concentrated on the solid-liquid-gas-heat coupling problem, the study of the waste gas of the municipal solid waste landfill is less. Gas diffusions, gas emissions, and gas collection are related to the secondary pollution problems of the municipal solid waste landfill. This paper established mathematical model which based on the solid-liquid-gas-heat interaction and researched the gas migration rule of the municipal solid waste landfills. The mainly work are as follows: (1) the definite conditions of dynamic model, (2) the solution of dynamic model, (3) results and analysis. The main conclusions are as follows: (1) Pore pressure along the gas flow direction is nonlinear distribution and shows decline trend. As time increases, the pore pressure of each horizontal section decreases. (2)The volumetric strain of the municipal solid waste landfill is nonlinear distribution along the gas flow direction and shows an increasing tendency. As time increases, volumetric strain of each horizontal section increases.(3)As the change of time, the pore pressure first increases, then decreases.(4) In the initial stage, as the change of time, gas output increases rapidly. When it achieves the maximum size, the production quantity of gas reduces and gradually tends to be a quantitative value.
Analysis on Common Quality Problem during Prefabrication of Reinforced Concrete Shaft Lining in Vertical Shaft of Mine
Authors: Liang Xu Li , Wang Fei , Wang Hua Ming
Published: May 2011

Reinforced concrete shaft lining were prefabricated on the ground at one vertical shaft engineering in Tangshan city,and the strength grade of concrete is up to C60. Take this vertical shaft engineering as the example,some problems may be encountered in the process of production of reinforced concrete shaft lining has been discussed.Furthmore, it also puts forward methods to solve the problems available for prefabrication of shaft lining in the future.
Determination of Meso-Compositions in Granite Images Using Bayes Discriminant Analysis
Authors: Xu Jin Ming , Zhou Yi Jun , Lu Chen Da
Published: May 2011

Granite is generally composed of the minerals such as quartz, feldspar and mica. Distinguishing types and distributions of these meso-compositions are of significantly importance in analyzing the properties of granite in practice. In the current study, the Bayes rule was used to classify the compositions in granite images. The grayscale threshold based technique was used to initially distinguish the meso-compositions in the original image. Six parameters, including the average, variance, contrast, correlation, energy, homogeneity of grayscale values, were extracted from the granite images and selected as the variables characterized minerals in the classifier. A linear discrimination function is then obtained. The meso-compositions of the granite images from different sites were used for the purpose of validation. The image processing was coded into a program and can be automatically run. The result shows that the grayscale threshold based technique and Bayes classifier proposed herein may provide a lot of valuable information both in distinguishing the meso- compositions in rock materials and in analyzing those in the field of the civil engineering.
Model Test Research of Pile Body Modulus on the Long-Short-Pile Composite Foundation
Authors: Ge Xin Sheng , Zhai Xiao Li , Xue Jiang Wei
Published: May 2011

In order to study the impact of pile modulus variation on the long-short-pile composite foundation,the relation between bearing capacity and settlement, distribution of the axial force and skin friction along pile, pile-soil stress ratio, load sharing ratio and the bearing mechanics of long-short-pile composite foundation with long and short piles were studied based on laboratory tests in three different conditions: Long pile(Aluminum) with short pile (pentatricopeptide repeats, PPR), Long pile(polyvinyl chloride, PVC) with short pile (PPR), and Long pile(Aluminum) with short pile (PVC). Conclusions were as follows: The settlement of long-short-pile composite foundation decreased with the increasing of long piles modulus, meanwhile, the value of long piles axial force increased, and the value of short piles axial force decreased, and the pile-soil load sharing ratio(LSR) increased. On the other hand, there are few influence on settlement, long piles axial force, and pile-soil load sharing ratio when the modulus of short piles modulus changed, except that the value of short piles axial force and short piles modulus increased or decreased on the same direction.
A New Approach for Dynamic Stability Analysis of the Slope
Authors: Yang Run Lin , Feng Zhe
Published: May 2011

The slope stability analysis is of importance for the practical engineering, and has received widely attention. Generally, the calculation process of the traditional methods is complex. In this paper, a new method was presented to analyze stability of the simple homogeneous slope, in which the safety factor and the max slip displacement of the slope under seismic excitation can be derived based on the principle of the minimal potential energy. The proposed method was efficient and did not require any iterative process for calculation. In order to evaluate its performance, a numerical example was studied to analyze the slope stability. The numerical results show the proposed method is valid and feasible by comparing with the numerical method.
Uniaxial Mechanical Properties of Sandstone under Cyclic of Drying and Wetting
Authors: Yao Hua Yan , Zhang Zhen Hua , Zhu Zhao Hui
Published: May 2011

Water is an important factor that influences the mechanical properties of rock. Uniaxial compressive experiments have been carried out on sandstone under different cyclic times of drying and wetting. The corresponding complete stress-strain curves are obtained, and characteristics of deformation and failure are analyzed. Test results show that when sandstone samples are submitted to cyclic of drying and wetting, the uniaxial strength and Young's modulus of sandstone obviously decrease. Then, the improved Duncan constitutive model is developed, which can do better in describing sample’s deformation behaviors subject to different cyclic times of drying and wetting. Introduction
Design Method of Long-Short-Pile Composite Foundation Base on Tangent Modulus In Situ Loading Test Curve
Authors: Liu Peng , Yang Guang Hua , Zhang Yu Cheng
Published: May 2011

The settlement of each part of the composite foundation, such as the foundation mat, cushion, soils and pile head, is recognized as equivalent under normal working conditions. On the basis of this, the corresponding load on long-short pile and soils can be derived easily from each individual p-s curve. The p-s curve of the composite foundation can be pictured in terms of the mutual actions of all the components mentioned above. and thus the corresponding settlement with load will be determined. Meanwhile, the p-s curve can be obtained via the undisturbed soil hyperbola tangent modulus method, which not only characters the nonlinear relationship between load and settlement very well, but also shows the deformation compatibility among those components. It is found that designed bearing capacity of soil is much higher than the reality based on usual design norms of composite foundation, while pile load is greater than the designed ones, which can be credited to the deformation compatibility of pile-soil not considered.
Dynamic Tests Research on Solidified Body Capability of Soil Stabilizer
Authors: Li Sho Hong , Tao Xi Gui , Shen Yue Guo , Zhang Yao
Published: May 2011

In order to get anti-dynamic load capabilities of solidified bodies with soil stabilizer which is a kind of hydraulic cementing material, tests were carried out on three sorts of solidified bodies under contact explosion. According to three different sorts of solidified material objects of soil, sand and detritus, three groups’ pieces of solidified bodies were prepared. Tests above show that anti-dynamic load capabilities of solidified bodies are at least two times than raw materials, and the capability of soil solidified body is the best than the others.
Experimental Study on Shear Mechanical Characteristics of Soil-Structure Interface under Different Normal Stress
Authors: Xia Hong Chun , Zhou Guo Qing , Du Ze Chao
Published: May 2011

The direct shear mechanical characteristics of soil-structure interface under different experimental condition were studied systematically using the DRS-1 high normal stress direct and residual shear apparatus. The results show that the normal stress is an important factor which determines the mechanical characteristics of soil-structure interface. The curve of shear stress-shear displacement presents strain softening when the normal stress<3MPa, linear hardening when =3~5MPa and strain hardening when12MPa, separately. At the same time, the volume of the soil expands when <3MPa and contracts when >3MPa. But the volume of the soil expands and contracts simultaneously during the process of direct shear when =3MPa.The roughness of the interface influences not only the shape of the shear stress-shear displacement curve but also the shear strength of the interface. Under same normal stress condition，the shear strength of interface increases with the roughness but the influence degree of interface roughness reduces gradually with the increase of normal stress. The grain breakage degree is different under different normal stress. It increases evidently with the increase of normal stress.
The Study of Support Replacement Technology about the Bracing System of Pile and Oblique Bracing
Authors: Liu Yan , Liu Jun Yan , Hou Yue Zhen , Jin Bai Xi
Published: May 2011

The bracing systems of pile and oblique bracing have obvious advantages in big and deep excavation. Because the study about the removal of oblique bracing is rare, the use of this system is limited. This author would study the transfer of internal forces and deformation issues in the process of the exchanging support through an example, from the design and construction, and the result will be verified through the measurement. The study has showed that the removal of such bracing shall tack the coordinating role of space in account, and use the collaborative computing method to remove the diagonal braces in several subregion and sections. And reached some interesting conclusions, these can provide reference for this design and construction.
Experimental Research on the Pile-Base Post-Grouting Effects of Piles of Liao River Bridge
Authors: Diao Ying Lu , Dai Guo Liang , Gong Wei Ming
Published: May 2011

Static load tests were carried out with Osterberg method on 3 bored piles formed in Liao River Bridge. Bearing capacity, base resistance and frictional resistance were obtained before and after base grouting. Based on the test results, the ultimate bearing capacities of piles were increased for 14.74%~43.87%, that of pile bases were increased for 89.57% ~ 163.49% and the frictional resistances were most increased for 31.20%. The pile bearing behavior was improved. Not only base resistances were improved after grouting, but also frictional resistances were improved by bettering the characteristics of soils and interfaces between piles and soils. After grouting, pile base resistance ratio of pile bearing capacity increased, and some frictional piles changed into end-bearing frictional piles. The frictional resistance of lower pile increased more than that of upper pile after grouting. The slurry penetration height of base grouting had a certain range, which was affected by quantity of mortar intrusion, grouting technology, grouting pressure and geological structure.
Non-Linear Finite Element Analysis of Squeezed Branch Pile
Authors: Zhou Min , Wang Zhong Fu , Wang Si Wei
Published: May 2011

In this paper, in order to analyze the capability of squeezed branch pile under different work condition and the cooperation mechanism between the pile and soil, non-liner numerical simulation was carried out using ANSYS. In the finite element model, the elastic-perfectly plastic Drucker-Prager material was assumed for soil. Contact interface elements were placed between the pile and soil. It showed that the squeezed branches took lots of the load, and the ratio it took was related to the load and the elastic modulus of soil; the plastic section of the soil was run-through from bottom to the top; the horizontal displacement of the top soil was moved to the pile, but the horizontal displacement of the soil of the bottom was moved away from the pile; the squeezed branch will break away from the soil above the squeezed branch when the load was at a certain value.
Influence Research of Correlation of Random Variables on Structural Reliability
Authors: Fang Yan Feng , Chen Li Yan , Gao Hua Xi
Published: May 2011

In this paper, the influence of correlation of variables on structural reliability is discussed. Using importance, condition and duality sampling techniques of Monte Carlo method, accepted accuracy can be obtained. For the limit state function, the correlation of random variables will influence structural reliability, and the influence can be described. For the case of positive correlation, reliability will increase as the the correlation coefficient raise. For the case of negative correlation, reliability will drop as the correlation coefficient raise. The level of influence depends on the slope of limit state equation in standardized coordinate. When k=1, the influence attains maximum intensity for both cases.
Analysis Quantitatively of the Quality of Solidified Waste Matrices with the Ratio of Binder to Waste
Authors: Wang Yue Xiang , Liao Ying
Published: May 2011

To understand the strength behavior of solidified waste matrices as building materials, sewage sludge as a kind of municipal solid waste had been solidified/stabilized by a binder constituted of Portland cement and stone material powder. Based on the experiment data, a mathematical model relating the strength gain of solidified sludge matrices to the ratio of binder to waste is proposed by statistical analysis. The proposed method is then verified with available test data.
Experimental Study on Structural Properties Influencing on Shear Strength of Soft Clay
Authors: Wang Jiang Feng , Li Yong Le , Gao Yan Bin , Yang Yong Xiang
Published: May 2011

The direct shear tests were conducted with undisturbed and reconstituted soft clay, then the structural influence on shear strength was studied, and the laws were got. No matter shear strength of slow shear or consolidated quick shear on undisturbed and reconstituted soil have not peak values, strength line of reconstituted soil is a slash, but the shear strength line of undisturbed soil is obviously a broken line. The internal friction angle of undisturbed and reconstituted soil is basically the same. There are good linear relationship between internal friction angle and plastic index of clayey soil. The amplitude of internal friction angle of reconstituted soil decreasing with plastic index increasing is less than that of undisturbed soil. From wf-lgp curve can be seen, with the increasing of vertical stress, water content of shear failure decrease gradually, and linear correlation of each curve is very good.
Study on the Influence of Seismic Wave Inputting Interface on the Earthquake Response of Deep Soft Sites
Authors: Chen Ji Hua , Zhou Ai Hong , Wang Qiu Jun , Xu Ying Jiao
Published: May 2011

Earthquake effects of two typical deep soft sites selected from Tianjin(site 1)and Shanghai(site 2) are studied when the vertical inputting earthquake waves are located in different depth of sites. As far as the shear wave velocity of soil layers is concerned, seven kinds of soil layers in site 1 and eight soil layers in site 2 are selected as the vertical imputing interfaces of earthquake waves. Two acceleration waves recorded during Taft earthquake and Northbridge earthquake are selected, and the peak values of two waves are adjusted to be 0.35m/s2、0 70m /s2 and 0 98m /s2, respectively. The earthquake response of sites is calculated by SHAKE91 program. The results are compared to those of site when the input interfaces of earthquake waves are located in bedrock with shear wave velocity larger than 500m/s. The conclusion is as following: With the depth of input position (or shear wave velocity) increasing, the value of the ground acceleration response spectrum gradually closes to the actual data.; For the general building the soil layer with shear wave velocity for 400m/s or so can be chosen as the input interface, and the building with long natural vibration period should be treated seriously, and the soil layer whose shear wave velocity is above 500m/s can be chosen as the input interface.
Comparative Analysis of Universal High-Rise Building Design Software between Dynamic Characteristics and Measured Dynamic Characteristics
Authors: Shi Dong Yan , Long Jian Xu
Published: May 2011

Dynamic characteristics of the building is its own inherent characteristics, natural frequency is one of the main features. Using the earth pulsation and environmental incentive as inspiration vibration sources, testing and analysis of building the pulsation of the response signal and dynamic characteristics. Use of a complex building pulse test the dynamic performance is analyzed and the building of vibration frequency. Will get into the frequencies of the universal design software inversion get complex building conversion layers under actual work force value, and theoretical design value and the column were compared, and discuss the reasons.
An Innovation Simulation Method for Flow State Evolution Laws of Water Inflow and Inrush in Course of Tunnel Excavation (Part I: Theories)
Authors: Xu Zhen Hao , Li Shu Cai , Li Li Ping , Shi Shao Shuai
Published: May 2011

Hydrologic and engineering geological conditions of underground engineering and mining are highly complex. Geological hazards, especially water inflow or inrush, often occur during constructions. In order to get an insight into flow state evolution laws of water inflow and inrush in karst regions, as well as the influence of tunnel excavation, a numerical simulation method was proposed with COMSOL Multiphysics. Three water flow laws, Darcy’s law, Brinkman equations and incompressible Navier-Stokes equations, are coupled and linked with each other. Water pressure and velocity can be analyzed in the course of excavation, and it can be used for further study of risk control of water inflow and inrush.
Laws of Formation and Evolution of Pressure Arch in Coal Mining Adjoining Rock
Authors: Du Xiao Li , Song Hong Wei , Chen Jie
Published: May 2011

Based on numerical simulation of computing Software ANSYS, the curve of arching coefficient variation of pressure arch due to actual mining was analyzed aiming to a special mining face, the law of stress transfer and change in surrounding rock was discussed, and the evolving features and characteristics of pressure arch was obtained. The analysis and discussion show the following facts: Arch body will become thicker and stress in the arch body increases with working face’s driving distance increasing; the morphology of pressure arch transits from ellipsoid with long axis in the vertical direction to ellipsoid with long axis in the horizontal direction along the trend of working face; along the tendency of working face, the morphology of pressure arch is a ellipsoid with long axis in the vertical direction.
Study on Optimum Cross-Section of Gravity Retaining Wall Based on ANSYS
Authors: Zhang Shao Qin , Su Zhi Ye , Zhong Yan Fen
Published: May 2011

Based on the geometric properties of a gravity retaining wall, an optimal design model is proposed, and then the best cross-section of the gravity retaining wall can be obtained by using ANSYS optimal techniques. An example is given to verify the effectiveness and superiority of the optimal design method based on ANSYS, and the results show that the optimum design is better than the original one. Further, the comparison between the sub-problem approximation optimal method and the first-order optimal method is performed, and our investigation proves that the first-order optimal method is more economical and reasonable.
Modified SFG Model for Unsaturated Soils
Authors: Liu Min , Zhao Cheng Gang , Liu Yan
Published: May 2011

SFG model has some advantages that it is more flexible in modeling different types of unsaturated soils than most other models in the literature. However, there are some shortages in SFG model. Firstly, it did not take account the influence of degree of saturation on the deformation of soil. Additionally, the SWCC that was adopted in the SFG model is relatively simple and cannot reflect the relationship between the current void ratio and the degree of saturation. This paper firstly presents the modified model based on the SFG model. The modified model adds the degree of saturation into the volumetric model for unsaturated soils. In addition, it adopts a SWCC that can reflect the influence of current void ratio. The new yield surfaces are proposed. These new yield surfaces are not only the function of suction and mean net stress, but also the function of the current degree of saturation and void ratio of soil. The modified SFG model can model more types of the behaviors of unsaturated soils and is more reasonable than SFG model.
Fuzzy Comprehensive Analysis and Assessment about Slope Stability Based on the Mutation Theory
Authors: Liu Wen Fang , Li Hong Mei , Tian Bei Ping
Published: May 2011

This article will use the mutation theory with qualitative and quantitative analysis, and utilizes the membership function of fuzzy mathematics, then decomposes the slope stability assessment to multi-level objectives, and then carries on quantification recursion computation according to recursion formula. As a result, we can figure out the total mutation membership function value of the slope stability according to the different factors of the slope, finally we can carry on tne fuzzy comprehensive analysis and assessment about slope stability.
The Principal Stresses of Soil Mass in the Direction of Plane Strain
Authors: Lu De Chun , Du Xiu Li , Zhou An Nan , Yao Yang Ping
Published: May 2011

The characteristics of deformation and strength of soils under the plane strain condition can be simplified as a two-dimensional problem. How to easily and reasonably determine the value of principal stress in the direction of plane strain is the key point. Based on the Elastic-plastic stress-strain relationship for soil and test data under the plane strain condition, it is assumed that the relationship between principal stresses in plain strain direction and the principal stresses in the other directions is bilinear. The parameters of bilinear function are determined by one-dimensional consolidation and failure state. The principal stress in plain strain direction is expressed as a function of stress states and material properties. Compared with test results, the rationality of the proposed bilinear principal stress function is testified.
Buckling Analysis of Double-Limb Lipped Channel Section Member under Axial Load
Authors: Ma Qing , Lei Jin Song , Yin Wen Zhi
Published: May 2011

Double-limb lipped channel section steel member is formed by connecting two single limb members with bolts in order to improve the buckling performance. In order to research the buckling form and ultimate bearing capacity of members with different slenderness ratios under axial load, nonlinear analysis of buckling performance is done to this kind of section using the finite element analysis software ANSYS. The influence on bearing capacity caused by height-breadth ratio of section, height-thickness ratio of web and breadth-thickness ratio of flange is analyzed. The results show that: (1) for larger slenderness ratio, complete buckling occurs to the column mainly and the slenderness ratio has larger influence on buckling bearing capacity, while for smaller slenderness ratio, local distortional buckling occurs more; (2) in a certain range, the increase of height-breadth ratio could raise the ultimate bearing capacity of member, but excessive height-breadth ratio would make the ultimate bearing capacity decrease, (3) the increase of both height-thickness ratio and breadth-thickness ratio would decrease the ultimate bearing capacity.
The Stability Analysis of Underwater Slopes Based on Strength Reduction Method
Authors: Li Lin Yan , Liu Yin , Chen Hao , Wu Heng Bin
Published: May 2011

Present methods for stability analysis of underwater slopes are mostly confined to laboratory experiments and limit equilibrium method. This paper is based on strength reduction method, considering the deformation parameters of rock mass to discuss the stability of underwater slopes. Comparing the consequences, the sliding planes and safety factors agreed well with the result of limit equilibrium method. The applicability of strength reduction method for underwater slopes stability was well proved. When analyzing after changing the water depth, it was showed that there are more erosion effect induced and reduction for the parameters of rock mass, but little influence on the safety factor of underwater slopes.
Application Technique of Vertical Prestressed Anchor Retaining Earth Wall in Landslide Field
Authors: Ding Jun Xia , Yang Guang Qing , Xiong Bao Lin , Zhou Qiao Yong
Published: May 2011

The mechanism of one small slide in the FuChang road at the Taihang mountain is analyzed with the comprehensive exploration methods. It is brought forward that the small slide is a shallow layer crushed stone slide with the type of drawing – enlarging outside. The vertical prestressed anchor retaining earth wall is applied for safety correcting the slide with the economical and feasible correction principle. This method depends on the vertical prestressed force, pressed on the earth wall body which is made by the anchor in the foundation, to balance the sliding force of the slide mass. The design thinking of the vertical prestressed anchor retaining earth wall is analyzed in details and the construction technology and technique essentials is introduced in this paper. The efficiency of the method is indicated by its well correction result.
Stress Calculation for a Double Layer Shaft in Special Strata
Authors: Zhou Yang , Zhou Guo Qing
Published: May 2011

A stress calculation method has been established for the double layer shaft in special strata. After some simplifications of the mechanical model, the problem was broke down into three subproblems, and a Saint-Venant solution was obtained by solving and adding up each subproblem. An example for certain double layer shaft was presented, and the stress results were compared with the single layer shaft under the same conditions. The fourth strength theory was applied to study the safety of the shafts, and the results show that, the safety for the inner layer of the double layer shaft is better than the single layer shaft, while the safety of the outer layer is relatively worse. We indicate that the application of this double layer shaft is advantageous for the safety production of the mine, and the outer layer of this shaft is the fragile area that needs to be repaired primarily.
An Improved Elasto-Plastic Model for Unsaturated Soils
Authors: Dong Jian Jun
Published: May 2011

The strength and deformation behaviors of unsaturated soil can be approximately described by elasto-plastic constitutive model that was proved by abundance academic and test researches. The Barcelona elastic-plastic model is an excellent model that can simulate the strength and deformation of unsaturated soil. But their calculated result of shear strength is low. So an improved Barcelona model is settled by using drop-shaped shear yield surface and hardening theory of dual stress. The results show that the improved model can more accurately predict the strength and deformation behaviors of unsaturated soil under suction-controlled triaxial compression stress states.
A Simplified Calculation Method for Spatial Effect in Large-Long-Deep Foundation Pit and its Analysis
Authors: Lei Ming Feng , Peng Li Min , Shi Cheng Hua , Zhang Yun Liang , Li Wen Hua
Published: May 2011

According to the research status of construction spatial effects in large-long-deep foundation pit: mainly focus on numerical simulation, but theoretical research is not too many by now, a simplified method for calculating the construction spatial effects of large-long-deep foundation pit in cohesive soil was advanced. The soil layers around deep foundation pit were equal to cohesion-less isotropic soil mass by introducing the concept of equivalent internal friction angle. And then, by means of limit equilibrium analysis method combined with soil plasticity upper bound theory and associated flow rule, the spatial effects of two 3D failure modes: tension crack-shear and pure shear in deep foundation pit was studied concretely, and the corresponding formulas of spatial effects coefficient were put forward, also two examples were analyzed. The research results indicates that the method, which can complete by hand-calculation, avoids the defects of low efficiency, high cost and long period in numerical simulation, and the distribution characteristics and value size of spatial effects coefficient could be obtained directly from its calculation results, which can be used as guidance for the supporting structure, construction scheme design and the test points or sections choice in process of information monitoring.
Limit Analysis on Stability of Cracked Slope Induced by Earthquake
Authors: Ding Yu , Dang Chao , Shao Yu Bin , Zou Xiao Dong
Published: May 2011

Intense earthquake shaking inevitably ruptures the rockmass along the fissures and bursts mountainous slopes, and these understable slopes are namely cracked slopes. For such slopes, aftershocks, rainwater infiltration and others factors will inevitably induce crack propagation and the crack thus gradually accumulates to be the cutting boundary that controls the slope deformation and failure. To understand how the slope stability varies in the process of cracking expanding, upper bound approach is employed to assess the cracked slope in Wenchuan earthquake epicenter considering the effects of crack propagation, rainwater infiltrating and earthquake. The results conducted in this paper indicate that the crack propagation lowly reduces the slope stability and it does not directly destabilize the slope. But the crack length owing to propagation inevitably increases the probability of slope failure, which more depend on the filling water in the crack and the earthquake intensity.
Foundation Design for the Shanghai Center Tower
Authors: Xiao Jun Hua , Chao Si , Zhao Xi Hong
Published: May 2011

This paper describes design process of foundation of Shanghai Center Tower, the China’s tallest building. The foundation system is piled raft founded on deep deposit of delta of Yangtze River. The geotechnical condition and the design progress including the selection of pile type and bearing stratum, pile capacity, raft thickness, foundation settlement will be outlined. The settlement is an important issue in soft soil area for super-tall building, and the optimized design of pile foundation stiffness to reduce differential settlement is also presented in this paper.
Study on Time-Space Motivation and Operation Mechanic of Landslide - A Case of Zhenzilin Landslide in Sichuan-Tibet Highway
Authors: Jin Xiao Guang , Hong Wei , Zhu Ling , Wang Lai Bin
Published: May 2011

The time-space movement feature of landslide was a geological process that landslide mass change from a state to another under the effect of internal and external factors. The ground surface and deep displacement feature of landslide with time and space was a reflection and externalization also a trace record of landslide time-space movement. Particularly, deep displacement of landslide provided direct and reliable evidence for studying space-time motion characteristics of slide. This paper studied on ZhenziLin landslide in Sichuan-Tibet highway, based on monitored deep displacement information of boreholes in landslide. It systematically analyzed time-space movement features and operation mechanic of integral revived area, disturbed deformation zone and foreland slump zone of landslide from the aspects of accumulated or relative displacement and displacement vector etc. of confirming or potential slide plane and hole top at different time. Results obtained provided data and dependence for studying landslide stability prediction.
Research on Chaotic Characteristic for Settlement of Road-Tunnel Composite Structure
Authors: Liu Zhen , Zhou Cui Ying
Published: May 2011

According to settlement of road-tunnel composite structure, relying on the Connecting Engineering Project at Shenzhen of Shenzhen-Hong Kong Western Corridor Project, settlement time series is analyzed by chaotic dynamics. Combining with phase space reconstruction, the correlation dimension, the maximum Lyapunov exponent, entropy and complexity of the road-tunnel composite structure system is studied. The results show that the settlement development of road-tunnel composite structure is still stable and predictable completely, of which chaotic characteristic is not obvious. This research has a great significance for the settlement prediction and control of the similar projects.
Study on the Deformation of Retaining Structure of Pit-in-Pit Excavation
Authors: Huo Jun Shuai , Chen Juan , Gong Quan Mei , Zhou Shun Hua
Published: May 2011

There are more and more pit-in-pit excavations in cities, which include inner pit and outer pit. Owing to the inner pit excavation, pit-in-pit problem aroused and brought about accidents. For this reason, based on the co-construction, deep, and large pit-in-pit of Shanghai Museum of Natural History and Metro Line 13, the excavation influence between inner pit and outer pit was analyzed. The deformation of underground diaphragm wall under the condition of three different distances between outer pit and inner pit were compared through centrifuge model tests. Then, the effect of excavation width of outer pit on underground diaphragm walls was researched through numerical analysis. Results show that the deformation of outer underground diaphragm wall increased with the excavation width of outer pit, for the inner pit, the opposite was true. The critical influence distance between outer pit and inner pit was within 22 meter and 24 meter. According to the critical distance, the area adverse to excavation pit stability was identified.