The valve at the bottom of auger can prevent drilling bits entering hollow pipe during operation. When drilling pipe is taken out and concretegrout is injected, the valve will be opened.
In order to improve crack resistance of concrete, test and analysis are made on the influence of mineral compositions of cement on brittleness of sand grout.
为了提高混凝土的抗裂性能,本文主要从水泥矿物成分对砂浆脆性的影响进行试验研究分析。
3
To control foundation seepage and exit gradient, a plastic concrete cut-off wall, a grout curtain, and a set of downstream pressure relief Wells are incorporated in the design.