桥头软基典型性病害分析探讨

Analysis and Discussion of Typical Soft Foundation Diseases at Bridgehead

软基桥头病害在道路工程中十分普遍。在工程建设期,软基处治方式的不当往往导致运营期各种病害的不断产生,造成运营维护成本大,同时病害难以根除。现以珠海地区运营通车六年多的某桥桥头段工程处治为例,通过现场测量、勘察、地基检测、室内试验及数值模拟等手段,全面分析了桥头段病害发展的程度和发生的根源。分析结果表明:此处桥头软基段总体沉降大,沉降不均匀显著,下伏软土层物理力学性质运营期内未有改善,其层内的PHC管桩存在断桩、错位、倾斜现象,路基实测沉降量超过设计理论计算沉降量,路基存在严重侧向位移。

Soft foundation bridgehead diseases are very common in road engineering.The improper treatment of soft foundation in the construction period often leads to the continuous occurrence of various diseases in the operation period and causes the high maintenance costs.And also it is difficult to eradicate the diseases.Taking the treatment of a bridgehead project in Zhuhai,which has been open to traffic for more than six years as an example,by the means of field measurement,survey,foundation detection,laboratory test and numerical simulation,the development degree and causes of bridgehead diseases are comprehensively analysed.The analysis results show that the overall settlement of the soft foundation section at the bridgehead is large and the settlement is uneven and significant.The physical and mechanical properties of the underlying soft soil layer have not been improved during the operation period.The PHC pipe piles in the layers are broken,dislocated and inclined.The measured settlement of subgrade exceeds the settlement calculated by the design theory,and the subgrade has serious lateral displacement.