某海堤后方地面塌陷原因分析

Reason analysis of ground collapse in the rear of a seawall

采用现场调研和数值分析相结合的方法,分析某海堤后方地面塌陷的原因。首先结合现场调研结果,初步判断地面塌陷原因;其次通过建立饱和渗流本构模型,采用有限元法求解陆域回填料与海堤接触面各点渗透比降,与允许比降对比进行渗透破坏判别,明确地面塌陷原因;最后根据塌陷原因分析,提出有效的应对措施。地面塌陷是由回填料渗透破坏造成的,是海堤内坡倒滤结构破损和强降雨天气降水下渗共同作用的结果,通过修补倒滤结构和进行地面防渗处理,可有效防止地面塌陷的进一步发展。研究结果为成陆工程防渗设计和地面塌陷修补提供了重要的参考。

On-site investigation and numerical simulation are used to find out the reasons of ground collapse in the rear of a seawall.Firstly,the reasons of ground collapse are initially discussed according to results of on-site investigation.Secondly,constitutive model of seepage in saturated soil is built up,by which the seepage gradient of the interface between land backfilling materials and seawall material is solved by finite element method.Seepage failure is judged by making a comparison of the simulated seepage gradient and allowable hydraulic gradient,therefore,the reasons of ground collapse can be further verified.Finally,effective measures are put forward by the reason analysis.Results show ground collapse is caused by seepage failure of backfilling material.The ground collapse is caused by the infiltration failure of backfill,which is the result of the combined action of the inverted filter structure damage on the inner slope of the seawall and the precipitation infiltration in heavy rainfall weather.The further development of the ground collapse can be effectively prevented by mending the filter structure and preventing rainfall infiltration.The research provides an important reference for anti-seepage design and ground collapse mending.