由北京乾坤基础工程有公司承担的水利部“八五”水利技术开发基金项目──“地下连续墙液压抓斗成墙工艺试验研究”课题，年初通过了水利部科技成果的正式鉴定。1991年5月，北京乾坤基础工程有限公司从国外引进了用于地下拉率工程防沙柱和连续搜m4成槽施工的大型设备20吕，被列 The project of “Eighth Five-year” Water Conservancy Technology Development Project undertaken by Beijing Qiankun Foundation Engineering Co., Ltd., a project of “Experimental Research on Technology of Wall Clamping into Hydraulic Wall by Diaphragm Wall”, was formally approved by Ministry of Water Conservancy at the beginning of this year. May 1991, Beijing Qiankun Foundation Engineering Co., Ltd. imported from abroad for the underground rate of engineering sand control column and the continuous search m4 into the trench construction of large equipment 20 Lu, was listed