【摘要】：區(qū)間隧道近距穿越既有高速公路橋頭區(qū)域會(huì)加劇橋坡段不均勻沉降,易引起嚴(yán)重的橋頭跳車。文章以濟(jì)南地鐵R1線區(qū)間盾構(gòu)隧道下穿既有京福高速公路橋?yàn)楸尘?針對(duì)原加固方案僅考慮減小盾構(gòu)下穿對(duì)樁基的影響,而忽略對(duì)橋頭變形控制的特殊工況,采用數(shù)值模型對(duì)盾構(gòu)穿越過(guò)程中高速公路橋頭的變形規(guī)律進(jìn)行了分析。結(jié)果表明:采用原加固方案,先左線后右線的盾構(gòu)穿越順序?qū)p小既有高速公路橋頭變形更加有利,但仍會(huì)產(chǎn)生26.5mm橋頭差異沉降,不能有效防止橋頭跳車的發(fā)生。基于此,為保證盾構(gòu)下穿方案的順利實(shí)施,文章提出了一種基于水泥攪拌樁作為隔離樁,同時(shí)結(jié)合深層混凝土搭板的橋頭變形控制新技術(shù)。采用該技術(shù),橋頭最大差異沉降為4.0 mm,最大縱坡變化值為0.4‰,最大路基沉降量為6.5 mm,均滿足規(guī)范允許變形要求。
[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，

本文編號(hào)：2152952