真空预压下考虑排水板淤堵行为的修正砂井固结理论

从准三维固结理论出发,根据排水板在地基排水固结中的空间性及特殊荷载条件,推导出真空预压条件下的砂井固结理论。考虑到实际工程中排水板的淤堵行为对地基固结存在影响,分别进行梯度比试验及单井模型试验,结合试验结果建立考虑淤堵行为影响的修正砂井固结理论。通过对比理论计算值与模型试验实测值,验证土体的超孔压实测变化曲线与理论曲线有良好的吻合度,理论计算公式能有效反映排水板在不同淤堵程度下对地基固结发展的影响。提出的修正砂井固结理论可为相关真空预压软基处理工程推广使用,做出更贴近实际的理论计算。

Amendments consolidation theory of vertical sand drains considering drainage board clogging in vacuum preloading

Based on the quasi-three-dimensional consolidation theory,the consolidation theory of sand drains under vacuum preloading was deduced according to special loading conditions and the spatial characters of the drainage board in the process of foundation consolidation.Gradient ratio test and the single well model test were conducted respectively in consideration of the drainage board clogging which had substantial influence and could not be ignored in practical programs,in combined with the experiment results,the consolidation theory of vertical sand drains considering clogging was then established.Comparison between the measured curve and theoretical curve concerning the variation of excess pore pressure indicated a good degree of agreement,and the theoretical formula can effectively reflect the impact of process of ground consolidation in different degree of clogging at different depth.The proposed amendment consolidated theory can be promoted to apply in the improvement of related soft ground using vacuum preloading method,and obtain relatively more appropriate theoretical calculations related to practice