充填站砂仓地基基础设计

在软弱地基上进行基础设计时,往往会遇到许多复杂的问题,如深坑,建筑垃圾等。结合位于软弱地基上的谷家台充填站砂仓的地基基础设计,重点分析了大承重结构的桩基础设计。     

某工程防渗区域地面地基处理方案比较

当前防渗处理的主要方式是铺设防渗膜,而防渗膜对地基的沉降要求比较严格,不允许出现较大的差异沉降。在软弱地基防渗区域,采用的地基处理方案既要满足地面荷载要求,又要满足防渗对地基差异沉降的要求。以实际工程展开比较,对比了多种软弱地基防渗区域地面地基处理方案,以期为工程的设计提供技术依据和参考。     

某综合门诊楼复杂软弱地基工程处理

本文通过对矿职工医院门诊楼基础地基采用砂石垫层置换浅层软土的设计与施工实践,论述了砂石垫层在复杂软弱地基的处理应用,证明了砂石垫层是一种简单、快速和经济的地基处理方法.     

砂石垫层设计和施工中的质量控制

砂石垫层的作用是:提高浅基础下地基承载力、减少沉降量、加速软弱土层的排水固结等。正由于砂石垫层诸多作用,当建筑物基础下的持力层比较软弱,不能满足上部荷载对地基的要求时,常采用砂石垫层来处理软弱土地基。本文仅对砂石垫层设计施工质量控制提出几点看法。 1 影响石垫层设计质量的因素 1.1 砂石垫层厚度(z)与基础底面宽度、长度的关系。 一般的基础底面长度、宽度及砂石垫层厚度z的确定,既要考虑砂石垫层地基承载     

塑料带排水固结法在软弱地基中的应用

本文通过工程实践，简要介绍重腐蚀湿法厂房──铜电解厂房软弱地基采用塑料带排水固结法的情况。简述了在该厂房软弱地基上进行高填土的地基处理的重要性及地基处理两种方案的计算和经济比较；并通过地基监测，评价塑料带排水固结法用于软弱地基的效果。     

如何减少软弱地基上建筑物的不均匀沉降

软弱地基上建筑物的不均匀沉降 ,常导致建筑物的开裂、破坏 ,严重地影响使用。本文主要从地基处理、建筑、结构、施工等方面对如何减少软弱地基上建筑物的不均匀沉降进行了论述。     

浅析换填灰土垫层法在矿山软弱地基处理中的成功应用

依据矿山西风井井架基础工程,阐述了换填灰土垫层法设计与计算,讨论了灰土垫层施工要求、工艺流程及处理效果,对今后软弱地基中工程的设计和施工具有指导作用。     

强夯法处理软弱地基在工程中的应用

本文通过对黄河阶地上的软弱地基处理方案的比较、论证，选用了一种简便、经济的设计、施工方法。     

多节扩孔灌注桩在地基处理工程中的应用

采用多节扩孔灌注桩对软弱地基进行处理,通过工程实例对其设计与施工进行了简单介绍,并指出了该桩型具有良好的抗拔或抗压力,有广泛的应用前景.     

垫层法处理软弱地基的设计及其适用范围

介绍垫层法处理软弱地基的适用范围、设计、施工、验收以及工程实例。     

白露河桥西端引道软基处理方案设计探析

通过鹰潭市40号路白露河桥西端引道软土地基处理方案设计，介绍了换填法、反压护道法和碎石桩法在道路交通工程路堤软基处理中的应用。     

Buckling of Cylindrical Tunnel Liners

Buckling of thin cylindrical shell liners used for the stabilization of soft ground tunnels is treated as the buckling of an elastic ring restrained radially and tangentially by an infinite surrounding elastic medium. Stiffness components for the elastic medium are derived and used to provide various levels of approximation for the elastic critical loads and associated modes of the liner when subject to overburden pressure loading. For most practical tunnel liners, elastic buckling is found to occur in modes having relatively short circumferential wavelengths. In these circumstances an approximation introduced into the critical pressure analysis allows both the lowest critical pressure and its associated mode shape to be represented explicitly in terms of a single “soft ground tunnel buckling parameter”; this single composite parameter encapsulates all the relevant ground and liner geometric and material properties. It is this closed-form analytical representation of elastic critical buckling that provides a particularly convenient basis for predicting elastic-plastic failure. When imperfections are introduced, liner collapse and the various forms of ground failure can be modeled by methods analogous to the Ayrton-Perry expression for columns. Two generalized imperfection parameters emerge: one for liner collapse and the other for each of three possible, soft ground, failure modes. It is suggested that the analytical simplicity of the approach should make it an attractive alternative basis for at least the initial, rational, design of soft ground tunnel liners.     

深层搅拌桩在软土地基的应用

以建在软土地基上的商住楼采用深层搅拌桩为实例,对该施工工艺加固地基时在设计、施工方面的一些问题作了分析、研究,揭示了由复合地基载荷试验获得的复合地基承载力标准值和通过理论公式计算的复合地基承载力标准值的关系.     

单层多跨钢结构厂房中柱纠偏技术

以初轧方圆坯厂房G48柱为个案，通过对这一单层多跨钢结构厂房中柱偏移原因和危害的全面分析，以及对纠偏方案的详细论述，介绍了软土地基上单层多跨钢结构厂房的结构变形治理技术，提出了对类似工程设计与施工及维护管理的建议。     

Behavior of Stone Columns Based on Experimental and FEM Analysis

A detailed experimental study on behavior of single column and group of seven columns is carried out by varying parameters like spacing between the columns, shear strength of soft clay, and loading condition. Laboratory tests are carried out on a column of 100?mm diameter surrounded by soft clay of different consistency. The tests are carried out either with an entire equivalent area loaded to estimate the stiffness of improved ground or only a column loaded to estimate the limiting axial capacity. During the group experiments, the actual stress on column and clay were measured by fixing pressure cells in the loading plate. Finite-element analyses have also been performed using 15-noded triangular elements with the software package PLAXIS. A drained analysis was carried out using Mohr-Coulomb’s criterion for soft clay, stones, and sand. The numerical results from the FEM are compared with the experimental results which showed good agreement between the results. Columns arranged with spacings more than 3 times the diameter of the column does not give any significant improvement. Based on the results, design charts are developed and a design procedure is suggested.     

Design Charts for Piles Supporting Embankments on Soft Clay

This paper describes the development and application of design charts for piled embankment designs. It outlines the computational approach adopted, the geotechnical profiles used, and the application of the design procedure using the charts. The soil profile used for the charts is representative of a Malaysian soft clay profile, involving a more or less normally consolidated soil, with a strength and stiffness that varies linearly with depth. Such a profile is typical of the ground conditions in a variety of countries in the Southeast Asian region. The design charts address the issues of pile capacity, settlement due to embankment load, settlement due to a temporary piling construction platform, and lateral response of piles near the edge of the embankment. The charts consider variations in ground conditions, embankment height, pile length, and pile spacing. An illustrative example is given to demonstrate the use of the charts.     

Performance of Geosynthetic-Encased Stone Columns in Embankment Construction: Numerical Investigation

This paper presents the results of a numerical investigation into the performance of geosynthetic-encased stone columns (GESCs) installed in soft ground for embankment construction. A three-dimensional finite-element model was employed to carry out a parametric study on a number of governing factors such as the consistency of soft ground, the geosynthetic encasement length and stiffness, the embankment fill height, and the area replacement ratio. The results indicate among other things that additional confinement provided by the geosynthetic encasement increases the stiffness of the stone column and reduces the degree of embankment load transferred to the soft ground, thereby decreasing the overall settlement. It is also shown that the geosynthetic encasement has a greater impact for cases with larger stone column spacing and/or weaker soil. Also revealed is that unlike isolated column loading conditions, full encasement may be necessary to ensure maximum settlement reduction when implementing GESCs under an embankment loading condition. Practical implications of the findings are discussed in detail.