- 摘 要
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(河南理工大學(xué)土木工程學(xué)院， 焦作 454000)
［摘要］對高噴插芯組合樁（JPP樁）的四種常用組合形式進行了模型試驗研究，通過在芯樁上粘貼應(yīng)變片和在樁底埋設(shè)土壓力盒等儀器對JPP樁軸力、樁側(cè)摩阻力及樁端阻力進行了測量，得到如下結(jié)論：水泥土與芯樁的不同組合形式對JPP樁承載力有較大影響；水泥土分段后，形成類似葫蘆狀的表面，增大了樁與樁周土的粗糙度，并且每段水泥土端部均能提供一定的端阻力，樁承載力提高明顯；組合段位置對樁承載力也有較大影響，水泥土與芯樁下部組合時樁側(cè)摩阻力增大明顯，下組合的JPP樁承載力表現(xiàn)出比分段組合1的JPP樁承載力大的特點，組合段宜設(shè)計在JPP樁下部；工程設(shè)計中，JPP樁宜采用3段以上的分段組合形式，并將分段組合放在芯樁的中下部，根據(jù)土層性質(zhì)分段高壓旋噴水泥土，從而達到節(jié)約造價、提高樁承載力的目的。
［關(guān)鍵詞］高噴插芯組合樁; 組合優(yōu)化; 承載性能; 荷載傳遞; 模型試驗
中圖分類號：TU470 文獻標(biāo)識碼：A 文章編號：1002-848X(2014)08-0015-06
Experimental research on combination optimization and bearing mechanism of jet grouting soil-cement-pile strengthened piles
Ren Lianwei, Li Guo, Dun Zhilin, Yang Quanwei
(School of Civil Engineering, Henan Polytechnic University, Jiaozuo 454000, China)
Abstract: Model test was carried out for four kinds of combinations of jet grouting soil-cement-pile strengthened piles (JPP pile). Axial force, shaft resistance and pile-top resistance were measured by strain gages pasted on core pile and earth pressure cells buried in pile bottom, and the following conclusions were obtained that different combinations forms of cement-soil and core pile have great impact on bearing capacity of JPP pile. The gourd-shaped similar surface caused by the cement-soil segment increases interface roughness between the JPP pile and soil, and each cement-soil top can provide some top resistance, which improves bearing capacity significantly. Segment locations have great impact on the bearing capacity of JPP pile. Shaft resistance increases significantly under cement-soil combination with the lower core pile. Bearing capacity of lower combined JPP pile is larger than segment-1 JPP pile, so combined segment should be set in the lower part of JPP pile in engineer design. In the engineering design, JPP pile should adopt three sub-combinations above. Combined segment should be placed in the lower of core pile, and jet grouting cement-soil should be segmented according to soil characteristics, so as to save cost and improve bearing capacity.
Keywords: jet grouting soil-cement-pile strengthened pile; combination optimization; bearing mechanism; load transfer; model test
*河南省重點攻關(guān)項目（122102210119），國家自然科學(xué)基金項目（41102169）。
作者簡介：任連偉，博士，副教授,Email:renhpu@163.com。
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