明渠整治工程下穿高铁桥梁安全性影响分析

Analysis of Safety Impact on the Ditch Training Works under-crossing High-Speed Railway Bridges

为研究市政与高铁交叉工程对高铁的安全影响问题,选取青山港二号明渠综合整治下穿天兴洲大桥工程为对象,结合工程特点、规范及条文制定了安全影响评价标准,定性分析出造成高铁桥墩水平变形的主要施工步为基坑填挖方、不对称加载、高压旋喷桩地基加固等。针对以上施工步进行三维有限元定量数值分析,提出高压旋喷桩对临近铁路桥墩影响的等效计算方法。研究发现,对黏土淤积层进行高压旋喷桩加固会导致临近铁路桥梁基础产生较大水平变位,采用非挤土桩基础进行地基处理可以明显减小临近铁路桥梁基础的水平变位。研究成果可为同类高铁工程施工及安全评定提供借鉴。

To evaluate the influences of nearby municipal networks on the safety of high-speed railroad,this paper takes the No.2 Qingshan Channel underpass Tianxingzhou Railway Bridge as the research object. Safety evaluation standards are developed based on the engineering characteristics and corresponding codes. Qualitative analyses show that the horizontal deformations of high-speed rail piers are mainly induced by foundation excavation/filling, asymmetric loading, and foundation stabilization using high-pressure jet-grouting piles.Three-dimensional finite element analyses are carried out to quantitatively evaluate the effects of the abovementioned steps. Equivalent calculation method is proposed to calculate the effects high-pressure jet-grouting piles on nearby piers. Results indicate that foundation stabilization using high-pressure jet-grouting piles may lead to large horizontal deformations on foundations of adjacent railway bridges, and the horizontal deformations can be greatly reduced by using non-squeeze out soil piles. Research results can provide beneficial references to the construction and safety assessment of similar projects.