软土地基穿堤涵管裂缝原因分析

工程实践中发现软土地基沟埋式涵管常出现裂缝问题,主要是不均匀沉降和受力不均匀所致。本文以广东省某涵闸为研究背景,结合现场调查、原位试验和有限元模拟等手段,对涵管受力及裂缝产生原因进行分析,通过研究发现,地基处理方式不同,作用于涵管上的荷载是不同的,当地基处理较刚时,与地基土形成较大沉降差时,作用于涵管上的荷载将较大于土柱荷重,若考虑不充分将会使涵管受力超出结构承载力,从而造成开裂,同时,对于刚性桩复合地基的应用,应增加褥垫层协调应力,结果对软土地基上涵管设计具有参考意义。并在此基础上提出一些建议,为同类工程避免裂缝产生提供参考。

Causes for cracking of culverts through the embankment on soft soil foundation

In engineering practice, problems of cracking of the channel-buried culverts on a soft soil foundation often appear as a result of unevenness in settlement and stress. Using a case study of the culvert project in Guangdong, this paper provides an analysis on the mechanics and causes for the cracking, based on field investigation, in-situ tests, and finite element simulations. This study reveals that the loads on the culvert depend on the effects of foundation treatment. If the foundation is much more rigid after treatment, the differential settlement between the pile and foundation soil will be relatively large and as a result, culvert load will also be larger than the weight load of soil columns. Without a full consideration, such a large load in this situation would exceed the bearing capacity of culvert structure, hence causing cracking. The results also indicate that for the culverts buried on a rigid pile composite foundation, a cushion layer could coordinate the distribution of stress, which is a significant guidance to the design of culverts on soft soil foundation. And on this basis, precautions against culvert cracking are suggested for similar projects.