Experimental Study and Measures on Engineering Characteristics of Diatomite Subgrade in Shengzhou

Abstract

This paper takes the newly built railway passing through the diatom land area of Shengzhou and Xinchang in Zhejiang Province as an example. And based on the field test of soil samples, this paper pointed out that due to low natural density, large void ratio, high water content, dry shrinkage and wet expansion, relative deformation and strength, The diatomite are not suitable to be directly used as building foundation. Based on the static load of single pile, bearing capacity of composite foundation and in-situ vibration test of foundation bed, it proposed that CFG pile, plain concrete pile and reinforced concrete pile are suitable for diatomite foundation reinforcement. While screw pile has insufficient bearing capacity, due to soil compaction effect and poor pile forming effect of high pressure jet grouting pile. CFG and plain concrete pile composite foundation can meet the requirements of diatomite subgrade deformation, and plain concrete pile is much better. The raft structure has better integrity. The capillary waterproof and drainage board can significantly improve the waterproof and drainage effect, and reduce the adverse effect of dynamic load on diatom soil foundation. Based on the slope rainfall test, it is proposed that diatomite natural slope is easy to form network cracks and induce shallow landslide under the action of dry wet cycle. In addition, the effect of gentle slope and skeleton on Diatomite slope is better.