滇池流域既有地下管廊无损加固处治技术

The Non-destruction Underground Pipeline Rehabilitation Technology in the Dianchi Lake Basin

对于不具备开挖加固处治条件的既有地下结构物,其加固方式通常只能选择非开挖桩式方案,但由于滇池流域地层中含有泥炭质土层,其特殊的物理及化学性能,无法与水泥有效结合,水泥浆喷入泥炭质土层后不会形成固结体,且泥炭质土遇水呈流塑状,桩式加固方案往往难以达到加固软弱土层的目的。针对这一现状,结合滇池流域既有市政路下管廊因土体滑移产生裂缝的现状,通过进行泥炭质土层中成桩试验及对既有地下管廊的稳定性分析,提出了高压旋喷桩＂墙隔离＋桩处治＂技术控制既有管廊周边软弱流塑层的影响,解决了既有地下管廊沉降、滑移造成开裂的问题。

For existing underground structures that could not be replaced with new ones under open-cut,the rehabilitation can only be performed throughout the non-excavation piled methods.However,due to the soft and highly compressible organic peat soil layer in the Dianchi Lake basin area,its special physical and chemical properties of subsurface soil prevents the applying of soil-cement column method since the soil particles cannot effectively harden by the introduction of the cement slurries.Further,the organic peat soil turns into plastic paste when the water is encountered.Therefore,the soil-cement method cannot be applied.To rehabilitate the defected municipal underground utility pipes in Dianchi Lake area,the isolation walls and columns formed by the jet grout method was proposed throughout the trial test in organic peat soils.The result by this improvement was prove to be satisfactory.