公路软土路基沉降规律及施工控制

Research on Settlement Law of Highway Soft Soil Roadbed and Construction Control Technology

结合广东省龙川-怀集公路TJ20标段沿线相关路基工程地质状况,采用水泥搅拌桩加固法及换填加固法两种方案对公路软土路基进行加固处理。针对加固后的软土路基进行沉降监测,以荷载试验验证两种公路软土路基处治方案的加固效果,分别得出其沉降变化情况及各方案对应的适用场景。验证结果表明:水泥搅拌桩加固方案适用于路基软土3.0~9.5m厚度的路段,换填加固方案可实现就地取材,适用于路基软土在3m以下厚度的路段;换填加固方案总体沉降量中以软土部分沉降量为主,换填土沉降量相对较小;水泥搅拌桩加固方案处治后的软土路基沉降量与软土压缩特性及含水率直接相关,表现为先快后慢,前45d沉降量可达总量的50%;两种加固方案均能确保处治后的软土路基具备足够的路基承载力。

Being based on the engineering geological conditions of the relevant roadbed along the TJ20 Section of Longchuan-Huaiji Expressway in Guangdong Province,two options,cement mixing pile reinforcement and replacement reinforcement methods,have been adopted to reinforce soft soil roadbed of the highway.Settlement monitoring of the reinforced soft soil roadbed has been carried out,and the reinforcement effects of the two road soft soil roadbed treatment schemes have been verified by load tests,and the settlement changes and the corresponding applicable scenarios of each scheme have been obtained.The research results have shown that the cement-mixed pile reinforcement scheme is suitable for roadbeds with soft soil thickness above 3.0m and large thickness soft soil distribution,and the settlement control effect of this scheme is better after construction;the replacement and reinforcement scheme can achieve local material acquisition and is suitable for roadbeds with the soft soil thickness being less than 3.0m in the small thickness soft soil distribution area;the overall settlement of the replacement and reinforcement plan is mainly the settlement of the soft soil part,and the settlement of the replacement soil is relatively small;the soft soil after the treatment of cement mixing pile reinforcement plan sub grade settlement is directly related to the soft soil compression characteristics and moisture content.It is fast and then slow.The first 45d settlement can reach 50%of the total;both reinforcement schemes can ensure that the treated soft soil subgrade can provide enough subgrade bearing capacity.