黄河三角洲沿海滩涂井场填方设计与施工

Design and execution of well site backfilling in beach ofthe Yellow River Delta Coast

摘要:

中国地质调查局“海域天然气水合物陆地试采工程”项目组在山东省东营市的沿海滩涂地区建设了一处钻井试验基地。该钻井井场地基土是黄河三角洲的典型粉沙质粘土，存在微振液化特性。对比填方方案在造价、工期、环保和适用性等方面的优缺点，选择灰土垫层施工方案并严格控制施工质量。灰土垫层可以形成有效的隔水层，隔离地下水上升通道和地表水下渗通道，切断微振液化的根源，同时杜绝场地内工程污水的下渗。填方施工全程采用静压压实填土配比，避免了孔隙水上升、土体产生微振液化效应。填方区域分为重载区和轻载区，采用不同的填方方案，既满足了承载力要求，又节约了成本。该填方方案取得了良好的施工效果，为试验基地的顺利运行提供了保障。

关键词:钻井井场;沿海滩涂;微振液化;灰土垫层;填方;黄河三角洲

Abstract:

The project team of China Geological Survey “Land Trial Production of Natural Gas Hydrate in Sea Area” has constructed a drilling test site in the coastal beach area of Dongying City, Shandong Province. The foundation soil of the site is typical silty clay in the Yellow River Delta, which has the characteristics of micro-vibration liquefaction. By comparing the advantages of cost, construction period, environmental protection and applicability, the project team chose the construction scheme of lime-soil cushion and strictly controlled the construction quality. Lime-soil cushion can form effective water-proof layer, isolate groundwater rising channels and surface water seepage channels, avoid the causes of micro-vibration liquefaction, and eliminate the seepage of construction waste water in the site. At the same time, static compaction was used throughout the backfilling construction to avoid the upward migration of pore water and micro-vibration liquefaction effect of soil. The backfilling area is divided into heavy-load area and light-load area. Different backfilling schemes were adopted, which not only met the bearing capacity requirements, but also saved costs. The backfilling schemes have achieved good construction results, ensuring the smooth operation of the test site.

Key words:well site; coastal beach; micro-vibration liquefaction; lime-soil cushion; backfilling operations; the Yellow River Delta