我国西北黄土的基本性质及其工程建议

Fundamental Properties of Loess from Northwestern China

本文简要介绍了我国黄土的分布及其风化源;提出了一种微观构造模型,用于解释其变形崩解特性和含水量轻微变化对高孔隙黄土力学性质的影响。并强调黄土的物理-化学和力学性质主要由小于5μm颗粒物质所控制。其中包含的成分有伊利石、蒙脱石和溶盐。文中给出了有关物理-化学和矿物组成研究的结果,并利用固结、三轴、流变和渗透试验确定黄土的基本力学特性。最后对实际工程问题提出了建议。

In view of the industrialisation of northwestern China, widespread research was undertaken on the properties of loess in this area. This paper deals with a part of these investigations.A brief report is given on the distribution of loess in China and their aeolian origin. A microstructure model of Chinese loess is suggested, which can explain its collapsible behaviour and the sensitivity of the mechanical properties of macroporous loess to slight changes of the water content. It is emphasised that the physico-chemical and mechanical properties of loess are mainly governed by the granular fraction <5μm, which contains illites, montmorillonites and soluble salts. Results of physico-chemical and mineralogical investigations are presented and analysed. The fundamental mechanical properties of loess were determined by oedometer, triaxial, rheological and permeability testing. Conclusions and suggestions are presented for practical engineering.