Study on the Law of Cement-Soil Mixing Pile Composite Foundation Settlement in Ancient Tower Translocation Project

Abstract

Longxi Tower translocation project is the first case of high-rise ancient tower structure translocation on soft soil foundation in China. Foundation treatment protocol and building materials are essential to control soft soil foundation settlement. Depending on Longxi Tower translocation project, firstly this thesis analyzed and confirmed control factors that impact foundation settlement and deformation; then combing with project experience, it selected cement soil mixing pile composite foundation method to treat soft soil foundation; and finally it confirmed the optimal solution to treat cement soil mixing pile composite foundation through analyzing the settlement law of cement soil mixing pile composite foundation. The analysis indicated that cement soil mixing pile composite foundation settlement are obviously impacted by translocation speed and retention time; foundation settlement and deformation level increase as translocation speed decreases and retention time increases; in the case that foundation settlement difference is not beyond 1/1000 of half the distance of track beams at the bottom of building, a treatment solution was made by analyzing how cement soil mixing pile settlement changes as translocation speed, retention time and other factors. The result showed that this treatment solution saved 42% of project cost more than the previous design solution. The research result of this thesis could be taken as a reference for the future similar projects.