Geoprobe直推钻机在城市水土环境地质调查中的应用

Application of Geoprobe drilling rig in investigation of the urban soil and water environment

为进一步查明某大型废弃工矿场地水土环境影响范围和程度,对其影响区进行详细的水土环境质量综合调查,基本查明“起步区”范围内土壤和地下水所受污染状况,进行风险评价并提出土地使用的初步对策与建议。设计水土环境取样钻孔386个,钻探工作量4180 m,要求定位采集土壤和地下水原状样品,以判定地层结构、含水层结构、岩土体力学等关键参数以及场地内土壤的垂向污染特征、污染深度和地下水坏境质量现状。为保证工程质量,采用了美国Geoprobe Systems(地探系统公司)Kejr分公司的Geoprobe系列直推钻机,采用静压或锤击不提钻取土法无水钻进、静压或锤击提钻取土法无水钻进和静压或锤击提钻临时取水钻进方法,有效解决了砂土层液化和钻孔涌砂而造成的取样量不足和样品扰动、污染等问题。本文对其设备、钻具、工艺方法及应用进行了介绍、分析。

In order to further find out the extent and severity of the impact of a large abandoned industrial and mining site to the soil and water environment,detailed quality investigation of the soil and water environment at the site(including the affected area)was carried out to find out the pollution status of soil and groundwater in the“starting area”with risk assessment,as well as preliminary solutions and suggestions for land use.A total of 386 soil and water environment sampling boreholes were designed with the drilling workload of 4180m.Undisturbed samples of soil and groundwater were required at designated locations to determine the key parameters such as stratum structure,aquifer structure,rock and soil mechanics,as well as the vertical pollution characteristics,pollution depth and groundwater environment quality of the soil at the site.In order to ensure the quality of the project,the Geoprobe series direct push drilling rig from Kejr Branch of Geoprobe Systems(Geo-Exploratin system Company)of USA was adopted.Water-free soil sampling was carried out by static pressing or hammering with or without tripping the tool,and temporary water samples were taken by static pressing or hammering,which effectively solved the problems of insufficient sampling quantity,sample disturbance and pollution caused by sand liquefaction and sand gushing from boreholes.This study introduces and analyzes the equipment,drilling tools,technological methods and applications.