中风化灰岩地层地铁车站基坑爆破施工技术

Blasting Construction Technology of Subway Station Foundation Pit in Moderately Weathered Limestone Stratum

徐州市泰山路车站基坑开挖主体下覆地层中大部分是中风化灰岩,属于较硬岩地基。针对这一特殊地质情况,在西侧场地采取深孔爆破、浅孔爆破与机械破碎相结合的方法,在东侧场地采取浅孔爆破与机械破碎相结合的方法。为了防止车站主体结构受损,在围护桩往里预留3 m采用静态破碎的方法。在对孔内溶洞进行爆破施工时,针对溶洞内炸药布置,提出了溶洞直列装药的处理办法,对于较大的溶洞采用机械破碎,该技术解决了较硬岩地基的开挖难题,取得了较好的结果,可为其他类似工程提供借鉴。

The stratum below the main body of foundation pit excavation of Taishan Road Station in Xuzhou City is mostly moderately weathered limestone,which belongs to harder rock foundation.In view of this special geological situation,the method of combining deep hole blasting,shallow hole blasting and mechanical crushing is adopted in the west site,and the method of combining shallow hole blasting and mechanical crushing is adopted in the east site.To prevent the main structure of the station from damage,the static crushing method is adopted for reserving 3 m in the support pile.During the blasting construction of the Karst cave inside hole,in view of the arrangement of explosives in the Karst cave,a treatment method of line charge in the Karst cave is proposed.For the larger Karst caves,the mechanical crushing is used.This technology solves the excavation problem of harder rock foundation and achieves good results.It can provide reference for other similar projects.