砂砾石地质条件下围堰单排高压旋喷防渗墙施工技术

Construction Technology of Single-Row High-Pressure Rotary Jet Grouting Impermeable Wall of Cofferdam Under Geological Condition of Sand and Gravel

高压旋喷桩施工技术是20世纪70年代在日本首先提出,在静压灌浆的基础上,利用水力切割搅拌地层,从而改变地层的结构组成,水泥净浆或水泥掺和其他胶凝性材料在地质中形成凝结体,达到地层加固和防渗的效果。施工机具和设备较为简便,对地基适应性较强,具有较好的耐久性,成本低。本项目由于河床坝段为砂砾石层,透水性强,采用单排高压旋喷施工技术达到了围堰防渗的效果,为大坝基坑开挖创造了良好的施工环境,降低了施工成本。

The high-pressure rotary jet grouting pile construction technology was first proposed in Japan in the 1970s.On the basis of static pressure grouting,water jet cutting and agitating strata were used to change the structural composition of the stratum.Cement paste or cement blended with other cementitious material was used to form coagulation in engineering geology to achieve the effect of stratum reinforcement and anti-seepage.The construction machinery and equipment used in the construction technology are relatively simple and the technology is adaptable to the foundation with good durability and low cost.Since the dam section of the project at riverbed is seated on the sand and gravel layer with strong water permeability,the single-row high-pressure rotary jet grouting construction technology was applied to achieve the effect of cofferdam seepage prevention,which has improved the construction environment for dam excavation and reduced the construction cost.