粘性土抗剪强度研究的现状与展望

在土力学计算分析工作中，抗剪强度（土的内摩擦角和粘聚力）是其中最重要的计算参数。能否正确地测定土的抗剪强度，往往是设计质量和工程成败的关键所在。本文综合论述抗剪强度研究工作中四个方面的重要问题：（１）应力、应变和加荷速率对抗剪强度的影响；（２）非饱和土的吸力和膨胀力与吸附强度的关系；（３）内摩擦角和粘聚力的特性及其变化规律；（４）从局部剪切发展到整体失稳过程中的应力变化和强度变化。岩土工程师需要对这些问题有全面的认识，才能对抗剪强度的试验资料作出正确的判断与应用。

PROBLEMS ON THE RESEARCH OF SHEAR STRENGTH OF CLAYEY SOILS

It is well known that shear strength (including cohesion and the angle of internal friction) is the most important parameter in the analysis and design of soil mechanics problems. Mistakes or inaccuracy in determination of shear strength parameter may result in failures of engineering projects. But very few engineers are familiar with the complexities and difficulties in shear strength research. It is the aim of this paper to present and evaluate the difficult problems in shear strength research under the following topics: (1) the influences of stress, strain, and late of loading on shear strength; (2) the variation of shear strength influenced by the change of suction in unsaturated soils; (3) the nature of the angle of internal friction and cohesion of soil, and their possible range of variations; (4) stress and strength variations during the process of general failure in soil mass. It is the necessity of geotechnical engineers to understand the general picture of these complex problems, so that they will be able to compare the reality with their laboratory reports and to make proper judgements in their designs.