直推钻探技术在污染场地调查中的应用现状研究

钻探技术是污染场地调查中唯一可直接获取地层样品的科学手段。其中直推钻探技术具有无冲洗介质、机动灵活、推进速度快、样品干扰小等优点。本文在已有国内外研究基础上,对比分析了西班牙TEC15和美国7822DT两类直推钻机的结构、推进工艺特点,后者具有较高静推进力和起拔力；研究了单管和双管两种直推钻具的结构组成和取样过程,并指出由于单管内设PVC取样套管,可有效保持土样的完整性,效率较高；分析了核磁共振(NMR)、土体水力测试(HPT)、膜界面探测(MIP)的技术原理和设备组成,MIP对污染物三维浓度探测具有更大技术优势；分析了国内直推钻探技术与设备的发展状况,并结合我国污染场地的地质条件和研究现状,指出能够实现精准控制的推进钻探和原位检测一体化装备和技术验证是主要的发展趋势。

Study on application status of direct push drilling technology in contaminated site investigation

Drilling technology is the only scientific method that can directly obtain formation samples in the investigation of contaminated sites. Direct push drilling technology has the advantages of no drilling fluid, flexible maneuverability, fast drilling speed, and small sample interference. Based on the existing domestic and foreign study, this paper compares and analyzes the structure and propulsion process characteristics of the Spanish TEC15 and the United States 7822DT rigs. The latter has higher static propulsion and pull-out force. Single pipe and double pipe are studied, and the structural composition and sampling process of the two direct thrust drilling tools. The results indicate that because the PVC sampling sleeve is set in the single pipe, the integrity of the soil sample can be effectively maintained and the efficiency is high. Nuclear magnetic resonance (NMR), soil hydraulic testing (HPT), membrane interface detection (MIP) technical principles and equipment composition are introduced, and MIP has greater technical advantages for the three-dimensional concentration detection of pollutants. The development status of domestic direct drilling technology and equipment is also analyzed, combined with the geological conditions of contaminated sites in China and research status, pointed out that the integrated equipment and technical verification of advanced drilling and in-situ detection that can achieve precise control is the main development trend.