一、概述膨胀土是一种粘粒成分主要由亲水性矿物如蒙脱石、高岭土、伊利石等组成，具有较大胀缩性能的高塑性黏土。这种土强度较高、压缩性很小，并有吸水膨胀，失水收缩和反复胀缩变形的特点，性质极不稳定。西安—南京铁路28标段位于河南省潢川县境内，年降水总量1 137ml，路 First, an overview of the expansive soil is a clay component mainly composed of hydrophilic minerals such as montmorillonite, kaolinite, illite and other components, with a large expansion of high plasticity clay. This soil strength is higher, the compressibility is very small, and has the characteristics of water absorption expansion, water loss contraction and repeated expansion and contraction, the nature of very unstable. Xi’an - Nanjing Railway 28 Lot is located in Huangchuan County, Henan Province, the total annual rainfall of 1 137ml, the road