漂卵砾石地层定向控制帷幕灌浆技术研究

Study on Directional Control Curtain Grouting Technology in Boulder-Cobble Strata

漂卵砾石地层具有沿河流下游方向渗透性更强的特点,在垂直河流方向的防渗帷幕难以形成。为解决这一问题,对基于预埋花管技术的灌浆管进行定向机械改造,利用脉冲灌浆的有限能量,使浆液沿垂直方向渗流,做到方向可控;并对灌浆材料及工艺流程进行了优化,以一定压力和单段吸浆量2个指标作为灌浆结束标准,有效解决了漂卵砾石等大粒径地层传统灌浆方法难以起压、水泥耗费量大、浆液渗透路径通常向河流下游延伸等问题。灌浆试验表明,定向帷幕灌浆技术对大粒径占比多的漂卵砾石地层具有较好的适用性,经灌浆处理后透水性大幅降低,满足中低坝地基防渗要求,对类似工程具有参考意义。

The boulder-cobble strata has the characteristic of stranger permeability along the downstream direction of the river,but the impervious curtain perpendicular to the river is difficult to form.In order to solve this problem,the grouting pipe based on embedded flower pipe technology is reformed by directional mechanical transformation.The limited energy emitted by the slurry from the pulse grouting pump is used to make the slurry penetrate along the square direction of vertical seepage,and the direction is controllable,and the grouting material and process flow are optimized.The two indexes of certain pressure and single stage suction are taken as the grouting end standard,the problems that traditional grouting method of large-size stratum such as boulder-cobble stratuml is difficult to start pressure,the cement consumption is large,and the slurry permeability path usually extends to the upstream and downstream of the river are effectively solved.The grouting test shows that the directional curtain grouting technology has good applicability to the large particle size floating gravel stratum.After the directional control grouting treatment,the water permeability is greatly reduced,which meets the anti-seepage requirements of medium and low dam foundation;it has reference significance for similar projects.