岩土结合地质条件下深基坑工程施工技术

Construction Technology of Deep Foundation Pit Under Rock-Soil Combinational Geological Condition

针对局促的场地条件及近于垂直开挖的需要,超深基坑上部的砂土层采用桩锚围护技术,下部的基岩层采用锚喷的支护技术,在岩土结合面处的坡面上设置了锚板墙来加强支护桩桩脚的嵌固.通过现场爆破试爆取得科学的、安全的技术参数,采用分层毫秒微差延时爆破技术结合局部静力破碎技术减轻爆破时的振动.工程实践证明,基坑支护体系得到了有效保护.

Considering the situation of straitness field and approximately vertically excavation, pile-anchor protection technique is applied in the upper sand layer of ultra-deep foundation pit, the shotcrete and rock bolt technique is employed in the bottom bedrock layer. In the slope of soil-rock combine surface, the anchor plate wall is set up to, strengthen the inlay firm of support pile foot. According to the technical safe parameters which are observed from field testing explosion, the combination of divide layers of milliseconds elementary difference delay explosion technique and the static broken technique are employed to release the exploding vibration. Engineering practice indicates that the present construction method is able to effectively protect foundation pit support system.