含锚索的粉细砂地层地下连续墙成槽技术

在含锚索粉细砂地质条件下同步进行锚索破除以及地下连续墙成槽施工时,极易引起槽壁坍塌现象。本文以昆明轨道交通5号线怡心桥站为背景,通过前期采用旋喷桩加固槽壁及旋挖钻破除锚索等措施先行破除锚索,减小了锚索破除过程中对槽壁土体的扰动;后期成槽施工过程中通过调整泥浆性能指标、合理选用施工机具等措施,不但提高了地下连续墙成槽质量,同时有效地抑制了成槽过程中塌孔现象的发生。这为今后类似条件下地下连续墙成槽施工提供了一定的借鉴。

Slotting Technology for Diaphragm Wall in Silty Sand Stratum with Anchor Cable

Under the geological condition of silty fine sand with anchor cable,it is very easy to cause the collapse of the trench wall when the anchor cable is broken and the trench construction of the underground continuous wall is carried out simultaneously.With the example of Yixinqiao Station of Kunming Rail Transit Line 5,the anchor cable is broken first by the measures of strengthening the trench wall with rotary jet grouting pile and breaking the anchor cable with rotary drilling in the early stage,so as to reduce the disturbance of the trench wall soil mass in the process of breaking the anchor cable.In the later stage of trenching construction,measures such as adjusting the mud performance index and reasonably selecting the construction machines and tools not only improve the quality of the trenching of the diaphragm wall,but also effectively inhibit the occurrence of hole collapse in the process of trenching.It could be used for reference in the similar construction conditions.