某中型水库导流引水隧洞施工技术
某中型水库导流引水隧洞施工技术
摘要：导流引水隧洞的施工是整个工程施工的关健，中小型水利工程的导流隧洞断面一般较小，施工机具以小型为主，常常采用全断面开挖方式施工。由于价格较低，外部施工条件也较差，对于不良地质地段的尤其是IV～V类围岩洞挖投入往往不足，极易造成跨口、冒顶等事故，造成工期拖延和费用的增加，对项目造成不利影响，因此，在不同的地质条件下，选择正确的施工方法是工程成功的必要条件，本文从该工程导流引水隧洞的锁口、开挖、支护等三个方面探讨隧洞施工中的技术问题,供同行参考。
关键词：水库；隧洞施工；超前小导管；开挖；支护
Abstract: the diversion of the diversion tunnel construction is the key project construction, small and medium-sized water conservancy project diversion tunnel of cross section are usually small construction tools to small give priority to, often use whole section excavation way construction. Because the price is low, external construction conditions also is bad, for bad geological areas especially IV ~ V class around the caves dug into often shortage, is caused extremely easily across the mouth, roof caving accidents, causing the delay time and expense increases, cause adverse effect to the project, therefore, in different geological conditions, choosing the right construction method of project is necessary for success, this article from the project the lock of the diversion tunnel diversion excavation, support the mouth, three aspects in the construction of the tunnel technical problems, refers for the colleague.
Keywords: reservoir; Tunnel construction; Advanced small catheter; Excavation; supporting
一、概述
导流兼放空引水隧洞总长489m，进水口采用塔岸式，隧洞为圆形断面，开挖断面直径3.8m,开挖面积为11.34m2，成型洞径3.0m，衬砌厚度40cm，采用C30砼衬砌。
二、隧洞边坡开挖和支护
导流洞进出口边坡采用CAT320型反铲挖掘机从开挖边坡坡顶自上而下分层开挖，人工开挖边坡顶部的山坡截水沟，再按施工图所设计的开挖边坡比进行开挖，土方及全风化层直接采用反铲挖掘机挖掘，翻渣至出渣平台，开挖出的土渣除部分用于出渣平台和临时便道填筑外，其余全部用CAT320型反铲挖掘机装渣、20t自卸车运渣至弃渣场。覆盖层的土方边坡经挖掘机开挖后，预留了20cm人工修整。 石方开挖钻孔采用YT28型手风钻，1台CAT320反铲挖掘机挖装，20t自卸车装运，按浅孔梯段采用自上而下分层和分段的开挖方式，边坡采用预裂和光面爆破，另外开挖至进出口洞脸位置时，为防止洞脸位置岩体爆破震动破坏，严格控制爆破药量，采用毫秒微差控制爆破。为确保边坡稳定，边坡支护采