区间隧道近距穿越高速公路桥头变形控制新技术研究
发布时间：2018-07-29 14:19
【摘要】：区间隧道近距穿越既有高速公路桥头区域会加剧桥坡段不均匀沉降,易引起严重的桥头跳车。文章以济南地铁R1线区间盾构隧道下穿既有京福高速公路桥为背景,针对原加固方案仅考虑减小盾构下穿对桩基的影响,而忽略对桥头变形控制的特殊工况,采用数值模型对盾构穿越过程中高速公路桥头的变形规律进行了分析。结果表明:采用原加固方案,先左线后右线的盾构穿越顺序对减小既有高速公路桥头变形更加有利,但仍会产生26.5mm桥头差异沉降,不能有效防止桥头跳车的发生。基于此,为保证盾构下穿方案的顺利实施,文章提出了一种基于水泥搅拌桩作为隔离桩,同时结合深层混凝土搭板的桥头变形控制新技术。采用该技术,桥头最大差异沉降为4.0 mm,最大纵坡变化值为0.4‰,最大路基沉降量为6.5 mm,均满足规范允许变形要求。
[Abstract]:The interval tunnel passing through the existing highway bridgehead area will aggravate the uneven settlement of the slope section of the bridge and will easily cause serious bridgehead jump. Based on the background of the shield tunneling in the R1 section of Jinan Metro through the existing Jingfu Expressway Bridge, the original reinforcement scheme only considers reducing the influence of the shield underpass on the pile foundation, but neglecting the special working condition of controlling the bridge head deformation. The deformation law of highway bridgehead during shield tunneling is analyzed by numerical model. The results show that using the original reinforcement scheme, the shield crossing sequence of the left line and the right line is more favorable to reduce the deformation of the existing highway bridgehead, but it will still produce differential settlement of the 26.5mm bridge head, which can not effectively prevent the bridge head from jumping. Based on this, in order to ensure the smooth implementation of shield tunneling scheme, a new technology of bridge head deformation control based on cement mixing pile as isolation pile and in combination with deep concrete slabs is put forward in this paper. With this technique, the maximum differential settlement at the bridge head is 4.0 mm, the maximum longitudinal slope variation value is 0.4 鈥，
本文编号：2152952
[Abstract]:The interval tunnel passing through the existing highway bridgehead area will aggravate the uneven settlement of the slope section of the bridge and will easily cause serious bridgehead jump. Based on the background of the shield tunneling in the R1 section of Jinan Metro through the existing Jingfu Expressway Bridge, the original reinforcement scheme only considers reducing the influence of the shield underpass on the pile foundation, but neglecting the special working condition of controlling the bridge head deformation. The deformation law of highway bridgehead during shield tunneling is analyzed by numerical model. The results show that using the original reinforcement scheme, the shield crossing sequence of the left line and the right line is more favorable to reduce the deformation of the existing highway bridgehead, but it will still produce differential settlement of the 26.5mm bridge head, which can not effectively prevent the bridge head from jumping. Based on this, in order to ensure the smooth implementation of shield tunneling scheme, a new technology of bridge head deformation control based on cement mixing pile as isolation pile and in combination with deep concrete slabs is put forward in this paper. With this technique, the maximum differential settlement at the bridge head is 4.0 mm, the maximum longitudinal slope variation value is 0.4 鈥，
本文编号：2152952
本文链接：https://www.wllwen.com/kejilunwen/daoluqiaoliang/2152952.html
