摘要
Abstract
To solve challenges such as difficult penetration,severe drill bit wear,and excessive cement slurry consumption encountered during the construction of ultra-deep triaxial cement-soil mixing piles in hard stratum,a systematic study was conducted based on a highway tunnel foundation pit project.The study encompassed construction machinery selection,drill bit structural modification,construction process optimization,adjustment of cement slurry mix ratio and grouting parameters,and stratum pre-treatment.The results show that:in sandy strata,using a blade-type drill bit with welded alloy steel cutters increases the maintenance interval from every 2-3 panels to every 15-20 panels,significantly extending its service life;pile quality is effectively ensured by adopting a skip piling sequence,a water-cement ratio of 1.5,grouting pressure of 6 MPa,and flow rate of 90 L/min;and the proposed method of"pre-drilling and soil replacement at intervals followed by mixing pile construction"prevents slurry loss,reduces cement consumption by 57.65%,and achieves significant economic benefits.关键词
硬质地层/基坑开挖/垂直支护/钻头改进/跳打顺序/地层预处理/钻进效率/压浆工艺Key words
hard stratum/foundation pit excavation/vertical shoring/drill bit modification/skip piling sequence/stratum pre-treatment/drilling efficiency/grouting process分类
建筑与水利
