福建沿海原状软土力学特性试验研究

Experimental Study on the Mechanical Properties of Natural Soft Soils Along Coast Area of Fujian Province

软土广泛分布于我国沿海地区,其较差的工程性质往往给工程建设带来不均匀沉降、承载力低,因此开展原状软土力学特性研究具有重大意义。以滨海原状软土为研究对象,通过系统的室内试验研究土体细微观、物理力学及压缩固结特性。试验研究发现:(1)浅层(4 m)和深层(24 m)土体细微观结构差异较大,浅层土中孔隙较多且呈鳞片状而深层土小孔隙比较低多为小孔。(2)土体压缩固结特性受到土体细微观和沉积环境影响,变化规律迥异,不同深度土体压缩性大小顺序具体为:29 m>4 m>24 m。(3)土体抗剪强度随深度先增大后减小,主要受到土体粒径分布及有机质含量的影响,有机质含量越高软土抗剪强度越低。

Soft soil is widely distributed in coastal areas of China,and its poor engineering properties often bring uneven settlement and low bearing capacity to engineering construction,so it is of great significance to analyze the mechanical properties of undisturbed soft soil.A systematic indoor test was conducted to investigate the microstructure,physical mechanics and compressive consolidation characteristics of coastal natural soils.The results are as follow.(1)there is a great difference in microstructure between shallow soil(4 m)and deep(24 m)soil.The pores in shallow soil are scalier,while the pores in deep soil are relatively few and mostly small holes.(2)The compressive consolidation characteristics of the soil are influenced by the microstructure and the depositional environment according to different rules,the order of compressibility of soil at different depths is:29 m>4 m>24 m.(3)Shear strength of the soil increases and then decreases with depth,which is mainly influenced by the particle size distribution and organic matter content of the soil,the higher the organic matter content,the lower the shear strength of the soft soil.