岩土工程技术

Integral of Mindlin's Stress Formula by Mathematics Software and Its Application in Geotechnical Engineering

Hu Pengfei, Zhang Zaiming

2008, 22(1): 1-5,19.

[Abstract](53) [PDF 326KB](9)

Abstract:
Efforts have been made to solve the problem of multiple integral of Mindlin's stress formula employing the mathematics software. And then the difference of distribution of stress fields in subsoil deduced by Boussinesq and Mindlin solutions was compared. Although the Boussinesq solution has been so widely used even for the analysis of problems concerning relatively deeply buried foundations, the verification was given that the introduced method would give more reasonable results for aforementioned problems.

Slope Stability Analysis Based on Strength Reduction Theory in FLAC

Liu Lipeng, Chen Qi, Zhang Bin

2008, 22(1): 6-10.

[Abstract](42) [PDF 959KB](10)

Abstract:
The shear strength reduction is combined with fast lagrangian analysis of continuum method(FLAC)to analyze the stability of soil slope, and the FLAC software post-processing ruction to dynamic demonstrate is used in generalizing shear strain increment,plastic areas occurrence and development situation. Moreover, convergence of statics equilibrium algorithm, mutation of displacement on characteristic position of slope as well as continuum of shear strain increment are used as cri- terion to estimate the stability of slope. The critical slip surface can be obtained when the slope become unstable. The method can vividly forecast the latent critical slip surface and evaluate the stability of soil slope by analyzing the international calculated example.

Viscous-Plastic Fuzzy Stochastic Damage Mechanism Researching on Earthwork Excavation

Wang Yajun, Zhang Wohua

2008, 22(1): 11-19.

[Abstract](66) [PDF 1726KB](6)

Abstract:
Generalized Uncertain Space O:^ξ(s,f) as tor pit-excavation engineering is set up with analysis on fuzzy and random characteristics of excavation damage evolution. Fundamental model of initial damage effective tensors is introduced here. Furthermore, the simulation of fuzzy stochastic damage on pit excavation application is realized by the help of viscous- plastic fuzzy stochastic damage incremental vector functions fabrication on the basis of fuzzy damping model on damage field source and sink definition. Fuzzy stochastic damage boundary value, namely, {Ω_u}, is derived here from linear operator, and viscous-plastic fuzzy stochastic damage constitution model as well as viscous-plastic non-linear fuzzy stochastic numerical algorithm, in this paper, are formulated with damage effective tensors. Thereby, viscous-plastic fuzzy stochastic damage ratio vector functions is setup here on the basis of viscous-plastic fuzzy stochastic damage finite element method algorithm. So, the fuzzy stochastic unloading damage model is deduced overall and fuzzy stochastic damage evolution and development is interpreted deeply on pit excavation construction.

Research on Vertical Swelling Energy of Expansive Soils Based on Work-Energy Principle

Miao Peng, Xiao Hongbin

2008, 22(1): 20-23,26.

[Abstract](38) [PDF 971KB](7)

Abstract:
Based on ameliorative experiment about swelling energy measurement of Nanning expansive soils, new technique of making soil samples and principle of work-energy, experimental investigation and theoretical derivation are done from the perspective of the energy. The relationship between Nanning expansive soils" swelling potential and initial water content, initial dry density are discussed. Test shows that static force compacting work and swelling released energy are all inversely related to initial water content. There are rectilinear relationships between compacting work, swelling energy and density. Moreover, density is the main influential factor of compacting work and swelling energy.

Optimum Design for Cross-section of Gravity Retaining Wall Based on Genetic Algorithm

Hu Xiaoping, Yuan Jian, Yu Ping

2008, 22(1): 24-26.

[Abstract](31) [PDF 292KB](7)

Abstract:
The genetic algorithm method is applied to the optimum design for cross-sectlon of gravity retaining wall. Then a cross-section mathematical model is established, and the selection, crossover, mutation algorithm of genetic algorithm and parameter coded in binary genes are set up. The result of the example shows that the method applied to the optimum design for cross-section of gravity retaining wall is effective and feasible.

Application of High Density Resistivity Method in Slop Investigation for Highway

Deng Jianhong, Li Wenbiao, Zhang Dingshan

2008, 22(1): 27-30,35.

[Abstract](39) [PDF 3345KB](8)

Abstract:
The basic principles and method of high-density electrical prospecting are introduced. Combining with engineering practice the result of comprehensive geophysic propection used in highway slop is explained.

Post Grouting Technology of Tensile Pile and Its Application

Zhang Wu, Gao Wensheng

2008, 22(1): 31-35.

[Abstract](59) [PDF 414KB](10)

Abstract:
The mechanism,method,effect and capacity mode of tensile pile with post grouting are introduced. The pile capacity of tensile pile is increased by the post grouting, and the construction difficulty is decreased, piling quantity is improved, constructional period is shorted and project expense is cut down.

Construction Technique for Deep Excavation Adjacent to Subway

Peng Shun, Duan Zhongyuan, Deng Tianwang

2008, 22(1): 36-40.

[Abstract](50) [PDF 554KB](9)

Abstract:
Deep excavation of Shenzhen galaxy hotel is in complex surrounding environments, and the depth is 18. 6m. Because the diversity of surrounding environments, some compound types of protection are adopted in the design of the protective structure of excavation, the main type are secant piles and artificially excavating holed secant piles, meanwhile, piles and anchors supporting, anchoring wall are adopted. Static blasting and cutting technique are adopted in dismantling the inner support. Other monitored indexes are all within the standard limit of the design. The characteristics of pit displacement and the reason of horizontal displacement occurs are analyzed. It can be a reference for the similar engineering projects.

Application of Crushed Stone Grouting Pile in Strengthening Deep Thick Soft-soil

Ye Chunlin

2008, 22(1): 41-46.

[Abstract](41) [PDF 927KB](10)

Abstract:
Crushed stone grouting pile is a new technique to improve soft-soil for blend as well as broken stones pile and grouting. At present, the new technique is in Yong-Tai-Wen and Wen-Fu of the coastal railway, bring about a strking effect in strengthening the deep thick soft-soil,and the demand of design is satified. The situation of the utilization is introduced about crushed stones-grouting-pile strengthening the deep thick soft-soil of new Wenzhou Station.

Application of Grouting Technology at Pile Tip

Zhu Kui, Zhou Pengfei

2008, 22(1): 47-50.

[Abstract](41) [PDF 670KB](11)

Abstract:
Bored pile sediment at pile tip is difficult to clear for construction technology restriction and soil at that is easy to dis-turb,and pile bottom bearing capacity is decreased. Grouting technology can solve this problem effectively. Based on an engineering project,grouting mechanical characteristics and construction technology of bored pile are studied, and some suggestions for grouting construction are put forward. It is held that bored pile bearing capacity increase obviously through grouting technology according to technical and economic comparison. Finally, several key factors influencing bearing capacity are discussed.

Mechanics Characteristic Analysis for Vibration and Impaction Stone Column Foundation of Large-diameter and High Displacement Ratio

Li Huawei

2008, 22(1): 51-54.

[Abstract](28) [PDF 362KB](8)

Abstract:
The distribution characters and general rules of pile-soil stress are discussed and new theory and opinion are proposed. These characters and rules are about filling-sea subsoil on eastern coastal area,consolidated by vibration and impaction stone column with large-diameter and large displacement ratio.

2008 Vol. 22, No. 1