高边坡下方管廊基坑支护设计方案比选

Comparison and selection of foundation pit support design schemes for a pipe gallery under high slope

人工填土高边坡的坡体稳定性差,因其土体未经压实,开挖极易引起坍塌,对周边建(构)筑物的基坑开挖产生严重的安全隐患。根据人工填土高边坡下南宁凤岭管廊基坑开挖的工程地质条件,分析了基坑设计的难点。对钻孔灌注桩、SMW工法桩、钢板桩3种管廊基坑常用的支护形式进行了对比,在综合考虑整体刚度和强度、基坑安全性、费用、施工速度等因素后,最终确定采用具有降低施工成本、可对施工材料重复利用、地下空间资源污染低的SMW工法桩作为该基坑的最佳支护方案。此方案可对今后类似工程的设计施工提供借鉴和参考。

The stability of the artificially filled high slope is poor,because the soil mass is not compacted,it will collapse once dug,which brings serious security risks to the excavation of the foundation pit of surrounding structures.According to the engineering geological conditions of the foundation pit of Fengling tube gallery in Nanning under the high slope with artificial soil filling,the difficulty of the foundation pit design is analyzed.The three commonly used supporting forms of pipe gallery foundation pit,including bored piles,SMW construction piles and steel sheet piles,are compared.After considering the overall stiffness and strength,foundation pit safety,cost,construction speed and other factors,it is determined that the SMW construction piles,which can reduce construction cost,reuse construction materials and pollute underground space resources lowly,is adopted as the best supporting scheme for the foundation pit.This scheme provides reference for the design and construction of similar projects in the future.