深埋斜井流砂层段透水钢板桩施工技术

Constructing Technology of Permeable Steel Sheet Pile for Quicksand Stratum in Depth Inclined Shaft

引黄入洛(阳)工程斜井施工中遇到了流砂层,施工条件复杂,施工受阻停滞,严重延滞了工程进度。针对深埋斜井流砂层段的施工难题,提出透水钢板桩施工技术。采用成品槽钢,沿槽钢纵向钻多排透水孔形成透水钢板,沿所加固的流砂层施工断面向围岩前方或下方以一定角度打入透水钢板,并使相临透水钢板一正一反相扣形成整体透水钢板桩,可根据不同施工区分别实施,使施工流砂层开挖区与所加固的围岩相对隔离,有效排出地下水,仅允许少量流砂流入施工区,形成少水低水压的施工区域,起到有效排水和固砂的作用,增强围岩的整体稳定性。工程施工表明,采用透水钢板桩施工技术,并结合两台阶法、超前加固技术、集水坑(井)降水技术等,对斜井全断面或者施工断面局部出现的流砂层段可进行有效施工,每月进尺达到15 m以上。该技术能有效降水固砂,施工操作简单,成本低廉,适用性强,可行、有效。

The quicksand stratum is encounted in the construction of depth inclined shaft in the project for transferring the Yellow River waterinto Luoyang, so it is complex when construction in this condition, the construction is retardated and stopped, and the construction progresspermeable steel sheet pile was proposed. The product channel steel was used to form permeable steel sheet by drilling multi-slice holes inlongitudinal direction of channel steel, and with a certain angle, the permeable steel sheet was driven into the anterior or inferior ofsurrounding rock of the strengthened quicksand stratum constructing section, and the whole permeable steel sheet pile was formed by theadjacent permeable steel sheet were reverse buckle. The permeable steel sheet pile could be respectively practiced according to differentconstructing areas, and the constructing quicksand stratum could be effectively isolated from surrounding rock and the underground watercould be effectively discharged. Only a little quicksand could flow into the workface, so the excavating region with less water and lower waterpressure could be formed. The constructing technology could effectively drain water and consolidate sand and the whole stability ofsurrounding rock could be enhanced. The practice shows the proposed constructing technology can effectively ensure the construction to bedone when quicksand stratum is full of the whole working face or local working face with progress of 15m monthly by combining with thetechnology of two-step excavating method, advanced reinforcement measures, pump pit or collector well dewatering technology, the proposedtechnology can effectively discharge groundwater and reinforce sand, is feasible and effective with simply operation, lower cost, strongapplicability and strongly extended usability.