贵州裸露型岩溶地下河系统污染防治技术——以遵义坪桥地下河系统污染防治工程为例

Pollution prevention technology for exposed karst underground river systems in Guizhou： Taking the pollution prevention project of Pingqiao Underground River System in Zunyi as an example

摘要:

裸露型岩溶区岩溶强发育、水文地质条件复杂，受污染的地下河系统通道隐蔽性强、污染防治难度大。本文以坪桥地下河系统污染防治工程为例，在近污染源的主径流通道实施“地下水防渗帷幕+污水抽排”工程措施实现近源截排。施工面临岩溶破碎地层易掉块卡埋钻、钻效低及岩溶强发育段浆液扩散距离远等难题。通过配备适宜的钻进工艺，采取纯压式灌浆、水泥砂浆灌填溶洞、低压限量及速凝浆液灌注等灌浆控制措施，保证了工程进度质量，实现了源头治理污染地下水的目的。“近源截排”对类似水文地质条件下地下水污染防治提供可借鉴的地学治理模式。

Abstract:

The exposed karst areas has the characteristics of strong karst development and complex hydrogeological conditions， which leads to the concealed nature of the channels in underground river systems and the challenges for pollution prevention. Taking pollution prevention project in Pingqiao Underground River System as an example， the measure of “underground impermeable curtain + sewage pumping and drainage” was used in the main flow channels near the pollution source to realize “near source drainage truncation”.The construction faced difficulties such as blockages and low drilling efficiency due to complex karst fragmentation and excessive waste of materials due to long grout flow distances in strong karst segments. Effective technical measures such as suitable drilling techniques， pure pressure grouting， cement mortar grouting to fill dissolution voids， low-pressure and limitated volume grouting and accelerated slurry grouting were employed to ensure the quality of the project， which achieved the goal of contaminated groundwater treatment from the source. The technology of “near source drainage truncation” provides a replicable geoscientific management model for contaminated groundwater prevention in analogous hydrogeological conditions.