摘要
隧道横穿深基坑,先于基坑施工,隧道初衬顶与结构底板底紧贴,导致基坑侧壁宽9.9m范围无嵌固,为解决这一难点,在桩墙+内支撑的原支护结构方案上提出,基坑侧壁局部外放并将嵌固端转移至隧道两侧,且增加无嵌固深度基坑侧壁横向受力钢筋的支护结构方案;该方案有能利用基坑内外扩后的空间进行放坡开挖,并且可利用坡体段进行基坑侧壁脚部加固、止水,同时不需要更换施工基坑侧壁的机械设备的优点,满足施工要求,此外,通过midas-Gen有限元软件和理正深基坑进行对比计算,结果表明此支护方案满足现行规范要求,综上所述方案可行。
Due to the tunnel constructed before the deep foundation pit excavated,the tunnel passes through the foundation pit,and the initial lining of the tunnel is close to the bottom of the structural floor,result that there will be wide 9.9 m range local unembedded depth in the side of foundation pit. To solve this difficulty,we put forward the feasibility scheme base on the original support structure of pile-wall＋inner support,that the side of foundation pit is partly released and the embedded end is transferred to both sides of the tunnel,as well as increasing the transverse force steel bar in the side of foundation pit wirhout embedded depth. This scheme has the following advantages：using the space inside the foundation to excavate with slop,reinforcing and sealing the side wall of the foundation pit with the slope section,even there is no need to change the mechanical equipment for constructing the side of foundation pit. In addition,by the comparison of the calculated by the finite element software midas-Gen and Lizheng,the results show that the support scheme meets the requirements of the current codes. In conclusion,the scheme is feasible.
作者
刘建辉
郭乾坤
Liu Jianhui;Guo Qiankun(Guangzhou Municipal Engineering Design ＆ Research Institute Guangzhou 510060,China)
出处
《广东土木与建筑》
2018年第1期4-7,共4页
Guangdong Architecture Civil Engineering
关键词
隧道上开挖
局部无嵌固深度
桩墙
基坑支护
有限元计算
excavation on tunnel
local unembedded depth in the side of foundation pit
pile-wall
retaining mad protecting for foundation excavation
finite element calculation
