黄河下游堤防截渗墙施工缺陷桩处理方案分析

A Brief Analysis on the Treatment Scheme of Defective Piles in Dike Cutoff Wall Construction in the Lower Reaches of the Yellow River

水泥土搅拌桩截渗墙是堤防加固的一种新方法,对于采用水泥土搅拌桩施工的截渗墙,在遭遇复杂地质条件下无法成桩并造成缺陷桩时,可以采用高压旋喷桩进行补桩施工。以黄河下游防洪工程(河南段)堤防工程截渗墙施工为例,提出缺陷桩处理方案:在已有的水泥土搅拌桩中心处垂直钻孔,直至钻孔到设计底部高程,开始高压旋喷注浆;在高压旋喷桩与水泥土搅拌桩搭接1 m范围进行反复喷浆,保证有效搭接,最后对水泥土搅拌桩内钻孔进行灌浆回填。经过检测,补桩符合设计要求。

The cutoff wall of cement⁃soil mixing pile is a new method for dike reinforcement.For cement⁃soil mixing pile cutoff wall,high pressure rotary jet grouting pile can be used for pile filling construction when it is unable to form piles under complicated geological condi⁃tions.Taking the construction of seepage cut⁃off wall of dike project of the lower Yellow River Flood Control Project(Henan section)as an example,the treatment scheme of defective piles was put forward:Drill holes vertically in the center of the existing cement⁃soil mixing pile until the borehole reached to the design bottom elevation and started high⁃pressure rotary jet grouting;and repeated spraying in the range of 1 m between the high⁃pressure rotary jet pile and the cement⁃soil mixing pile.In order to ensure effective lap,finally it grouted and backfilled the holes in the cement⁃soil mixing pile.After testing,the pile filling had met the design requirements.