冻结粉质粘土中锥形桩弹性阶段挤扩效应的研究

20世纪70年代, 在原苏联的乌克兰地区, 用锥形桩作基础建造了大量的多层或高层住宅, 取得了显著的经济效益. 我国的科技人员于20世纪80年代初期也开始了这方面的研究, 并于河北省的保定地区进行了试点工作. 但在冻土中采用锥形桩作基础, 迄今为止还未有报道. 通过对冻结条件下粉质粘土中锥形桩在竖向荷载作用下弹性阶段挤扩效应的分析, 根据厚壁圆筒受均匀内压时的弹性理论解答, 计算出了冻结条件下粉质粘土中锥形桩侧表面在弹性阶段末期的挤扩应力值, 并根据锥形桩模型在竖向快速加荷条件下的试验资料, 验证了公式的正确性, 结果令人满意.

Study on Expanding Effects of Cone Pile in the Elastic Stage in Frozen Silty Clay

According to elastic theory solutions of thick\|wall cylinder bearing internal uniform pressure, the expanding stress on lateral surface of a cone pile at the end of elastic stage in frozen silty clay are calculated through analysis of expanding effects of cone pile bearing vertical load. The validity of the formulation is verified on the basis of cone pile model experiments under rapid applied load. Calculated expanding stress value has a good fit with the model pile test value in the end period of elastic stage. In the experiment, ten model piles were tested. The maximum relative error between the experimental and the calculated values is 8\^94%, and the average absolute value of all errors is 5\^15%. At the same time, expanding stress of cone pile under unfrozen conditions can also be solved.