Discussion about shear liquefaction on cement flay-ash gravel pile composite foundation in high sensitive soil

Fleeing problem,reducing diameter,breaking pile and land subsidence, etc often happen during the application of twist boring concrete pumping piling technique in high sensitive soil.Based on dynamic property tests on high sensitive soil in Zhenzhou area,the mechanism of these problems caused by shear liquefaction is analyzed theoretically,and the range of the shear liquefaction,as well as some measures to prevent shear liquefaction,are discussed.