CAJ | 학술논문

某地铁深基坑工程，工程主体分布于富水上软下硬的复杂地质条件，设计选用三轴搅拌桩作为止水帷幕并要求三轴搅拌桩进入风化岩层，隔断基坑内外的透水层，搅拌桩如何进入风化岩是一个值得研究的技术难题。通过对三轴搅拌桩的机械选型、设计三轴搅拌桩钻头的结构形式、适用此地质条件下的施工参数等方面进行详细研究，实现三轴搅拌桩止水帷幕在泥质粉砂岩中的成功施工，达到彻底隔断透水层的目的。主要研究结论如下：1)富水上软下硬复杂地质条件下可以选用三轴搅拌桩作为止水帷幕；2)三轴搅拌桩入岩后，在类似地质条件下可选用钻孔桩+三轴搅拌桩代替地下连续墙作为围护结构体系，以节约投资。
모지철심기갱공정，공정주체분포우부수상연하경적복잡지질조건，설계선용삼축교반장작위지수유막병요구삼축교반장진입풍화암층，격단기갱내외적투수층，교반장여하진입풍화암시일개치득연구적기술난제。통과대삼축교반장적궤계선형、설계삼축교반장찬두적결구형식、괄용차지질조건하적시공삼수등방면진행상세연구，실현삼축교반장지수유막재니질분사암중적성공시공，체도철저격단투수층적목적。주요연구결론여하：1)부수상연하경복잡지질조건하가이선용삼축교반장작위지수유막；2)삼축교반장입암후，재유사지질조건하가선용찬공장+삼축교반장대체지하련속장작위위호결구체계，이절약투자。
The deep foundation pit under study is located in water-rich composite ground consisting soft strata at the up-per part and hard strata at the lower part. Three-axis mixing piles are designed as the water-stopping curtain of the foun-dation pit. The three-axis mixing piles are required to extend into the weathered rock so as to isolate the impermeable strata. Therefore, extending the three-axis mixing piles into the weathered rock is a technical challenge to be studied. In the paper, analysis is made on the type selection of machines for the three-axis mixing piles, a new type of drill bit is designed for the drilling machine, and construction parameters suitable for the geological conditions are studied. Conclu-sions drawn are as follows:1 ) Three-axis mixing piles can be used as the water-stopping curtain for foundation pits loca-ted in water-rich composite ground consisting soft strata at the upper part and hard strata at the lower part;2 ) Because three-axis mixing piles can be extended into weathered rock,“bored piles + three-axis mixing piles” may be used as retaining structures in geological conditions similar to those mentioned above to replace the diaphragm walls so as to reduce the investment.