物探技术在滩涂开发地块土壤信息探测中的应用

Application of Geophysical Technology in Soil Information Detection in a Tidal Flat Development Plot

滩涂开发地块可能存在用污染土填海或者非法填埋固体废弃物等污染隐患,掌握待开发地块的填土范围、填埋量、土壤机械组成等信息在土壤污染调查中非常关键.物理地球勘探技术具有破坏性小、调查效率高、刻画范围连续等优势,通过采用多种物探技术相互辅助结果呈现、钻孔取样校正等方式,可以较好地应用于此类型土壤信息探测工作,满足时间短与经济成本合理的调查需求.以某滩涂地块为例,利用电磁法和高密度电法区分地块的回填土及原生土区域,确认地下储罐和土层信息,服务于后续的污染调查采样方案制定和污染状况分析.探测结果表明:填土区域土壤主要以砂土、砂质黏土为主,无地下储罐或高金属含量污泥等物体,填土面积约65000 m^(2),探测结果与现场勘查情况和钻孔结果高度吻合,可为同类型存在填土或填埋物的场地的前期土壤信息收集提供参考.

Potential pollution hazards such as reclamation with contaminated soil or illegal landfill of solid waste was exited in tidal flat.It is very important to master the soil information such as the filling range,landfill volume and soil mechanical composition of the land to be developed in the soil pollution investigation.Geophysical exploration technology has the advantages of less destructive,high investigation efficiency and continuous description range.By using a variety of geophysical techniques to assist each other,the result presentation and borehole sampling correction can be better applied to this type of soil information detection to meet the short investigation time and cost-effective requirements.Electromagnetic method and Electrical Resistivity Imaging method were used to distinguish the backfill area and the original soil area of the tidal flat development site,serving the formulation of sampling scheme and pollution status analysis of follow-up pollution investigation.The results showed that the soil in the filling area were mainly composed of sandy soil and sandy clay without metal objects such as underground storage tanks or sludge with high metal content.The filling area was about 65000 m^(2),and the results of geophysical exploration method were highly consistent with the field investigation and drilling results.The number of sampling points could be reduced by at least 50 through the geophysical exploration,the cost of soil investigation could be reduced by at least 157,000 yuan.The investigation mode in this study provided a typical case for the early soil information collection of the similar urban filling sites.