我国红土工程地质研究新进展及今后主要研究方向

RECENT ADVANCES AND PERSPECTIVE STUDYING ON ENGINEERING GEOLOGY OF LATERITE STUDY IN CHINA

通过大量的文献阅读,总结出了我国红土已有研究的主要进展,提出了今后的主要研究方向。我国红土研究取得的主要认识有以下几个方面:(1)湿热气候是红土形成的最主要的环境条件;(2)红土的形成是一个脱硅富铁铝的过程,高岭石、伊利石、绿泥石等粘土矿物是红土的主要组成物质;(3)团粒结构是红土的基本结构单元,它主要由粘土矿物通过静电引力、范德华引力连结或游离氧化物的胶结形成,具有很强的水稳定性和较高的力学强度;(4)红土是一种高分散度、低压缩性的区域性土,剖面上具有明显的力学分带性;(5)红土主要的工程地质问题是具有一定的胀缩性、底部常有软土和土洞分布、容易引起地基变形和地面塌陷。今后我国红土研究的主要方向是:红土形成年代和形成速率的研究、红土微结构定量化研究、红土剖面系统研究、红土的分区分类评价、红工测试技术的改进和开发、全国不同类型红土分布图的编制等。

The advances on laterite study is discussed and the major aspects be studied on laterite in the future is put forward in the paper. The main advances are as follows： （1） the laterite is formed under wet and hot conditions during the Quaternary Periods （2） the formation of the laterite is in fact a process of desiliconization and enrichment of iron and aluminum; and the major contents of the laterite are clay minerals such as kaolinite,illite,chlorites （3） granular texture is a basic structure of the laterite, which is mainly composed of clay minerals and is of great stability against water solution and high dynamic strength. The clay minerals in the granular texture is joined or cemented by ionic bond, molecular attraction or vacillating oxides ; （4） the laterite is a regional clay of higher dispersiveness and lower compressibility as well as obvious dynamic horizon on vertical profile; （5） the major engineering problems of the laterite are collapse of earth surface and deformation of subgrade caused by the expansive and contractive features as well as the present of soft clays and earth caves under the laterite. The major aspects for leterite studying in China in the future are as follows： （1） to study the age and speed that the laterite is formed; （2） to measure the micro-texture of the laterite in quantity ; （3） to systematically grasp the change of the laterite properties on the vertical profile; （4） to survey and draw a map shown on various laterite over the country; （5） to divide the laterite into different zones and to assess them in engineering.