2005 Vol. 19, No. 5

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Analysis of Fuzzy Reliability for Retaining Wall Structure
Liu Fang, He Bengui, Gao Qian
2005, 19(5): 217-219,240.
[Abstract](50) [PDF 240KB](10)
Abstract:
Firstly the first-order second-moment theory in structural reliability analysis is outlined and the fundamental model of fuzzy reliability analysis for stability of retaining wall structure is set up.Then associating with real project condition,the specific mothod of reliability analysis for stability of retaining wall structure is illustrated,and finally the sensitivity analysis of parameters is put forward.
Fuzzy-Stochastic Math-Algorithm Analysis for Slope Stability Based on First-Order Approximation Theorem
Wang Yajun, Wang Yanjun
2005, 19(5): 220-224.
[Abstract](72) [PDF 375KB](5)
Abstract:
On the basis of harmonious FEM, by the help of First-order Approximation Theorem,the stochastic FEM mathematical model is set up, and the softening procedure for slope working function is realized with fuzzy models. The partial failure situation of JingNan Yangtz River Main dike section is researched comprehensively by fuzzy-stochastic mathematical algorithm.
Application of Neural Network in Predicting the Strength of the Steel Fiber Reinforced Concrete at Minus Temperature
Liu Yongsheng, Xu Dongmei
2005, 19(5): 225-226,232.
[Abstract](26) [PDF 216KB](5)
Abstract:
The BP neural network is established to predict the compressive strength/the flexural strength, the tensile strength and the shear strength of steel fiber reinforced concrete at minus temperature. The checking results show that the BP network could predict the strengths successfully by establishing the appropriate non-linear model and studying.
Prediction of Bear Capacity of Rock-socketed Pile by BP Neural Network
Wang Yonggang, Dong Wenyu
2005, 19(5): 227-232.
[Abstract](42) [PDF 389KB](9)
Abstract:
The most direct and credible method to calculate the bearing capacity of the rock-socketed pile is the static load test. But because the bearing capacity of the rock-socketed pile is very large and the expense of the experiment on rock-socketed pile is high and the experiment is very hard to go to the destroy point, so it is necessary to cut down the number of the static load test but not to reduce the precision of the resuh in the scope of the engineering. According to the former lest data, and on the basis of the BP neural network, and using the toolbox of the neural network in the Matlab, the influence to the bearing capacity of the rock-socketed pile by,several controllable element is concluded. Then the reasonable design parameters of the rock-socketed pile are confirmed. The analysis shows the practical function of BP neural network method in some degree.
Study on Filter Cake in the Filtration System of Geotextiles-Unstable Soils
Xu Jun
2005, 19(5): 233-236.
[Abstract](27) [PDF 288KB](4)
Abstract:
In the soil-geotextile filtration system, a large amount of fine particles will migrate under the drag forces exerted by the flow if the rail is internally unstable. A layer of thin filter cake is prone to be formed between the interface of soils and geotextiles. The thickness and permeability coefficient of the cake become the important factors affecting the fihration effect. Based on the theory of seepage and sediment in the porous medium, the relations between the cake's thickness and other factors such as geotextiles thickness and permeability coefficient, outside pressure, fine particles content are studied during the migration of fine particles in the process of unstable soils' filtration. The analytical expressions are given.
Mechanical Behavior of Tension and Shear Conditions Related to Unloading Fractured Rock Mass
Wu Hanhui, Yang Zhuanyun, Liu Hui
2005, 19(5): 237-240.
[Abstract](34) [PDF 282KB](7)
Abstract:
Under tension and shear conditions related to unloading of rock mass,a linear elastic fracture mechanics model of jointed rock mass is established. According to the model, the equations of stresses, strains and displacements of the region influenced by the crack but relatively far away the crack(the distance between the research point and the center of the crack is longer than the length of crack) are derived. They are important for evaluating the deformation of cracked rock. It is demonstrated by the comparison between computational results of these theoretical equations and the observed data from unloading test that this model are applicable for actual engineering.
Experimental Study of Mechanical Performance of Cement-Improved Loess
Ma Xuening, Liang Bo
2005, 19(5): 241-244.
[Abstract](39) [PDF 287KB](6)
Abstract:
Through many soil laboratory and theory analysis, compaction characteristics, compressibility, intensity mechanism and some major factors and the dynamic performace of cement improved loess under repeated load of train are discussed. It can be concluded that the performance of cement-improvde loess meets the design demand of rapid transit railway subgrade.
Analysis for Shallow Fill in Slope of Embankment Reinforced by Plants and Engineering Practice
Xia Qiong, Yang Youhai, Sun Yanying
2005, 19(5): 245-248.
[Abstract](58) [PDF 308KB](6)
Abstract:
The principle of loess slope reinforced by plants is introduced, the detailed analysis for the reinforcement effects of both Amorpha fruiticosa Linn and Caragana is made, combining with the BaoZhong railway project.
Study on Numerical Analysis Methods of Geotechnical Mechanics
Kong Desen, Luan Maotian
2005, 19(5): 249-253.
[Abstract](66) [PDF 432KB](10)
Abstract:
With the extension of geotechnical engineering domain, numerical analysis methods of geotechnical mechanics are developed rapidly,and many new numerical analysis techniques are advanced. The research status in quo and the last evolution of all these numerical methods are summarized through dividing them into two classes, that is, the continuous and the discontinuous deformation analysis methods. The superiorities and the deficiencies of these numerical methods are introduced emphatically. Also, the ideologies ways and suggestions of solving these problems are proposed.
Forecasting Ultimate Bearing Capacity of Single Squeezed Branch Pile
Gao Xiaojuan, Yang Xiaobin
2005, 19(5): 254-257.
[Abstract](39) [PDF 267KB](5)
Abstract:
This paper predicate the ultimate bearing capacity of squeezed branch pile based on 110 pile from different site bv hyperbola method,and compare with the results of the friction pile's. The results show that predicated curve is agree well with the filed measurement curve below ultimate load. The difference between the two curves is increasing when the top load of pile is approach to the ultimate load. The degree of error can not be constrained in 15% because of the complex transfer mechanism of this kind of pile. The predicated results of friction pile are better than that of squeezed branch pile. The precision is greatly relative to the condition of the property of soil and pile itself.
Experimental Study of Squeezed Branch Pile with Vertical Load
Zhou Lingling, Li Julong, Li Bin
2005, 19(5): 258-261.
[Abstract](38) [PDF 242KB](7)
Abstract:
Based on the results of slatic loading tests and measurements of body resistance and bottom resistance of six piles, the bearing capacity and deformalion behaviors of squeezed branch pile are analyzed. Further, through gray retated analysis the authentic bearing character of the squeezed branch pile is exposed.
Optimization Design of Cross Section of Gravity Type Retaining Wall
Luo Lin
2005, 19(5): 262-263,267.
[Abstract](62) [PDF 196KB](11)
Abstract:
In order to solve the problem that retaining wall cross section design computation is comparatively trouble and it is difficult to obtain the best result, taking top width and bottom width two major indexes in section design of gravity type vertical retaining wall as variable, the minimum cross section area as goal, according to calculating formula of anti-slide, anti-overturning, wall foundation stress and retaining soil request, the mathematical model of non-linear optimization is set up, and applied to the retaining wall section design of Daxin Bridge water control project, Excel is adopted to work out mathematical model, each optimization index of the minimum cross section area is obtained.
Characteristics of In-situ Stress Field in Dahuofang Reservoir Conveying-Water Tunnel
Sun Xiang, Yang Zirong, Zhao Zhongying
2005, 19(5): 264-267.
[Abstract](39) [PDF 255KB](6)
Abstract:
In order to find out whether the in-situ strees field affects rock mass stability in the area of Dahuofang reservoir conveying-water tunnel,geomechanics is applied to study the tectonic appearance.The evolution of stress field is clarified and divided into four stages firstly.Furthermore, based on the data measured,the distribution model of in-situ stress field is set up.The results indicate that this region is in middle horizontal tectonic stress field and the orientation of major principal stress is nearly EW. The angle belween maximum principal stress and tunnel axes is 39-46° which affects rock masses stability.
The Reliability Analysis on the Vertical Bearing Bored-Piles
Ge Jianlong, Wang Li
2005, 19(5): 268-271.
[Abstract](29) [PDF 275KB](5)
Abstract:
The formula for evaluating the loading force of the bored piles has been obtained by the data of static cone penetration (CPT) and static load test. Based on the model of one-dimension stationary Gaussian random fiekls of soils around the pile, the method of correlative function and wariable function is adopted to calculate the relevant range of the soils. Then the probability distribution of the capacity of the site piles is checked and the relevant statistics parameter is evaluated. Considering the efficiency of the bored piles, the impact has been obtained by using the data of the pile settlement. A1 last, the reliability index of the single pile and the bored piles has been calculated and compared the result to that doesn't consider random fields model. The reliability analyses of bearing capacity of bored piles has been carried out.

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