低能量强夯法加固粉质黏土地基试验研究

In-situ test study on low-energy dynamic consolidation method to improve a silty clay ground

结合上海某铁路集装箱中心站地基处理工程,针对其场区上部粉质黏土、下部砂质粉土的地基条件,对低能量强夯法加固此类地基的适用性进行了现场试验研究。通过对夯击过程中超静孔隙水压力随夯击次数、深度、距离的变化规律及在不同性质土层中的增长与消散规律的研究,提出了运用试验手段确定强夯夯击次数、夯点间距、有效加固深度及两遍强夯间隔时间等施工参数的方法。同时,用静力触探试验和标准贯入试验对地基加固的效果进行了检验,结果说明低能量强夯法加固粉质黏土地基的适用性,从而进一步拓宽了低能量强夯法的应用范围。

Based on a major construction project in Shanghai of which the ground consists of a silty clay layer in surface and underlying a sandy silt layer, in-situ test study on the fitness of low-energy dynamic consolidation method （LEDCM） is done. By analyzing the variation of excess pore water pressure with depth, distance and the impact number, and considering the increasing and dissipation regularity of excess pore water pressure in different soil layers, a method to choose the construction parameters of LEDCM such as the optimal impact number, the appropriate impact space, the effective strengthened depth and the reasonable interval between two impact passes, by experimental means is proposed. At the same time, the field detective trials including the static cone penetration tests and the standard penetration tests are given to evaluate the effectiveness of improvement, and the results indicate the validity of LEDCM to treat the silty clay ground and also further broaden the application range of LEDCM.