- 摘 要
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（安徽建筑大學土木工程學院， 合肥 230601）
［摘要］針對國內傳統(tǒng)水泥土攪拌樁存在的缺陷，介紹了變徑雙向水泥土攪拌樁技術，并對其施工機械和施工工藝進行說明。為了驗證變徑雙向水泥土攪拌樁的軟土地基加固效果，通過現(xiàn)場試驗和理論分析，分別就上部樁體擴徑（釘形攪拌樁）和中部樁體擴徑（中字形攪拌樁）這兩種典型攪拌樁樁型的攪拌均勻性、樁身強度與承載力、路堤荷載下復合地基工作性狀以及工程經(jīng)濟性等與試驗段內的常規(guī)攪拌樁進行對比。試驗結果表明，由于采用了變徑和雙向攪拌工藝，消除了溢漿現(xiàn)象，保證了樁身水泥摻入量，提高了樁身均勻性、強度及承載力；在路堤荷載作用下，采用變徑攪拌樁可比常規(guī)攪拌樁節(jié)約近15%的水泥用量。
［關鍵詞］釘形攪拌樁; 中字形攪拌樁; 常規(guī)攪拌樁; 施工工藝; 樁身強度; 樁承載力; 復合地基; 經(jīng)濟效益
中圖分類號：TU472.3+6 文獻標識碼：A 文章編號：1002-848X(2014)08-0031-06
Technique and application research of diameter-varied bidirectional soil-cement deep mixing piles
Xi Peisheng, Liu Bo
(School of Civil Engineering, Anhui Jianzhu University, Hefei 230601, China)
Abstract: According to the existing shortcomings of traditional deep mixing pile techniques in China, diameter-varied bidirectional soil-cement deep mixing pile technique was introduced as well as the deep mixing machine and construction procedure. In order to investigate the improving effect for soft ground improvement, comparison tests were conducted between T-shaped pile, “zhong”-shaped pile and traditional pile through site tests and theoretical analysis. The comparisons included the homogeneity of the pile, pile strength, the bearing capacity of the pile, the performance of composite foundation under the embankment loads and the economic benefits analysis. The test results indicate that due to crafts of diameter variation and bidirectional mixing, grout spill phenomenon is eliminated effectively. The sufficient amount of cement in pile is ensured. And the homogeneity, strength and the bearing capacity of the pile are improved. Under the embankment loads, diameter-varied bidirectional soil-cement deep mixing pile can save about 15% cement compared to that of conventional one.
Keywords: T-shaped mixed pile; “zhong”-shaped mixed pile; traditional mixed pile; construction procedure; pile strength; bearing capacity; composite foundation; economic benefit
作者簡介：席培勝，博士，副教授，高級工程師，Email：xipeisheng@163.com。
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