下穿填埋场隧道综合超前预报与防控措施研究

    COMPREHENSIVE GEOLOGICAL PREDICTION AND ENGINEERING COUNTERMEASURES FOR TUNNELING UNDER LANDFILL

    • 摘要: 深圳坂银通道鸡公山隧道的设计路线下穿了深圳下坪固体废弃物填埋场,由于钻孔分析等前期地质勘察无法在该区域开展,下穿填埋场隧道区段施工存在地质状况不明、填埋场渗滤液及填埋气泄露等风险,现有隧道施工超前预报体系不适用于隧道下穿填埋场引发环境灾害问题。针对该难题,本文基于地震预报法(TGP)、瞬变电磁法(TEM)、超前钻孔、取样化学分析等多种方法,构建了隧道下穿填埋场施工超前地质预报体系,并对下穿填埋场隧道区段的围岩质量和渗滤液、填埋气渗漏情况进行了探测与综合分析。结果表明:(1)综合超前预报方法能够提高隧道前方围岩级别判定准确性;(2)填埋场下方存在联通至隧道施工区域的潜在渗滤液渗流通道,但尚未有渗滤液下渗情况发生,隧道开挖过程也无有毒有害气体逸出;(3)针对渗滤液渗漏风险隧道区段,采取全包防水和提升防渗材料等级等方式,可有效保障隧道施工与运营安全。本文研究成果可为隧道穿越环境风险区域施工的超前预报工作提供参考借鉴。

       

      Abstract: The Jigongshan Mountain tunnel,part of the Banyin Expressway in Shenzhen,is designed to cross underneath the Xiaping Municipal Solid Waste Landfill. Due to the prohibition of preliminary geological surveys in the landfill region,the geological conditions and the distribution of leachate and landfill gas remain unknown in the tunnel section under the landfill. Moreover,considering the risk of environmental disaster,the traditional geological prediction methodology is no longer suitable for the project of tunneling under a landfill. This study develops an innovative strategy of geological prediction for tunneling under a landfill. It is based on multiple geological and geophysical methods. It includes tunnel geological prediction(TGP),transient electromagnetic method(TEM),geological drilling,and chemical analysis. We also performed comprehensive detection and analysis on the quality of surround rock and the distribution of leachate and landfill gas under the landfill. The results show the following findings:(1)The comprehensive prediction method can improve the accuracy of the determination of surround rock quality ahead of the tunnel. (2)Potential leachate pathways connecting the landfill bottom and the tunnel are detected,however,no leachate and landfill gas leakage occur yet. (3)In the tunnel sections with high leakage risk,enhancement of the lining material and waterproof layer is put into practice during tunnel construction. This study offers a valuable reference for similar investigative projects concerning tunnel construction in regions with potential environmental risk.

       

    /

    返回文章
    返回