ONE DIMENSIONAL ANALYTICAL SOLUTION FOR CONSOLIDATION OF A COMPOSITE GROUND WITH T-SHAPED DEEP CEMENT MIXING COLUMNS
-
摘要: 钉形搅拌桩是具有扩大头的新型水泥土桩。基于等竖向应变假设,推导出瞬时荷载下端承钉形搅拌桩复合地基桩间土的固结方程,基于双层地基一维固结理论建立了相应的固结解析解。然后,将复合地基固结度解析解与有限元数值解进行比较,评价解析解的计算精度。最后,通过对各主要影响因素的分析,研究钉形水泥搅拌桩复合地基的固结特性。结果表明:钉形水泥搅拌桩复合地基的固结速率随桩的压缩模量、扩大头下部水泥桩的置换率和它周围土体压缩模量的增加而增大。增加扩大头的直径,复合地基的固结速率随之小幅减小。扩大头的长度不到桩长的一半时扩大头长度的变化对钉形水泥搅拌桩复合地基固结速率的影响较小,扩大头的长度超过桩长一半以后钉形水泥搅拌桩复合地基的固结速率随扩大头长度的增加而快速增大。Abstract: T-shaped deep cement mixing (DCM) column is a new type of DCM column with an enlarged column cap. Based on the equal vertical strain assumption, the equations governing consolidation of the surrounding soil around a fully penetrated T-shaped DCM column was derived under instantaneous load. The corresponding analytical solutions were developed by using the one dimensional consolidation theory of a double-layer ground. Then, the accuracy of the proposed analytical solution was evaluated through the comparison of the consolidation rates of the composite ground from the proposed analytical solution with the FEA. Finally, the main influence factors were analyzed to investigate the consolidation behavior of the composite ground. The results showed that the consolidation rate of the composite ground increased with an increase in the constrained modulus of T-shaped DCM column, the area replacement ratio of the DCM column with small diameter under the enlarged cap and the constrained modulus of the subsoil around it. It decreased slightly with the increase of the diameter of the column cap. The length of the column cap had little influence on the consolidation rate when it was less than half of the length of a T-shaped DCM column. However, it increased rapidly with the increase of the column cap length when the column cap length is larger than half of that of a T-shaped DCM column.
-
刘松玉,易耀林,朱志铎.双向搅拌桩加固高速公路软土地基现场对比试验研究[J].岩石力学与工程学报,2008, 27(11):2272-2280. 朱志铎,刘松玉,席培胜,等. 钉形水泥土双向搅拌桩加固软土地基的效果分析[J].岩土力学,2009,30(7):2063-2067. 易耀林,刘松玉,朱志铎.钉形搅拌桩复合地基承载力特性[J].建筑结构学报,2010, 31(9):119-125. YI Y L, LIU S Y, PUPPALA A J, et al. Vertical Bearing Capacity Behaviour of Single T-Shaped Soil-Cement Column in Soft Ground:Laboratory Modelling, Field Test, and Calculation[J]. Acta Geotechnica, 2017,12(5):1077-1088. YI Y L, LIU S Y, PUPPALA A J. Bearing Capacity of Composite Foundation Consisting of T-Shaped Soil-Cement Column and Soft Clay[J]. Transportation Geotechnics, 2018, 15:47-56. 刘松玉,朱志铎,席培胜,等.钉形搅拌桩与常规搅拌桩加固软土地基的对比研究[J].岩土工程学报,2009, 31(7):1059-1068. LIU S Y, DU Y J,YI Y L, et al. Field Investigations on Performance of T-Shaped Deep Mixed Soil Cement Column-Supported Embankments over Soft Ground[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2012,138(6):718-727. YI Y L, LIU S Y, PUPPALA A J. Laboratory Modelling of T-Shaped Soil-Cement Column for Soft Ground Treatment Under Embankment[J]. Géotechnique, 2016, 66(1):85-89. 易耀林,刘松玉. 钉型搅拌桩复合地基荷载试验的三维数值模拟[J].东南大学学报(自然科学版),2008, 38(5):821-827. 易耀林,刘松玉,杜延军. 路堤荷载下钉形搅拌桩复合地基附加应力扩散特性[J].中国公路学报,2009, 22(5):8-14. 易耀林,刘松玉,朱志铎. 路堤荷载下钉形搅拌桩复合地基沉降特性[J].中国公路学报,2010, 23(5):1-7. PHUTTHANANON C, JONGPRADIST P, YENSRI P,et al. Dependence of Ultimate Bearing Capacity and Failure Behavior of T-Shaped Deep Cement Mixing Piles on Enlarged Cap Shape and Pile Strength[J]. Computers and Geotechnics, 2018, 97:27-41. 易耀林,刘松玉,杜延军. 钉形搅拌桩复合地基工程应用及其沉降计算方法[J].解放军理工大学学报(自然科学版),2009,10(5):456-460. LORENZO G A, BERGADO D T. New Consolidation Equation of Soil-Cement Pile Improved Ground[J].Canadian Geotechnical Journal, 2003,40(2):265-275. 谢康和.双层地基一维固结理论与应用[J].岩土工程学报,1994,16(5):24-36. 卢萌盟,谢康和,周国庆,等. 不排水桩复合地基固结解析解[J]. 岩土工程学报,2011,33(4):574-579.
点击查看大图
计量
- 文章访问数: 66
- HTML全文浏览量: 4
- PDF下载量: 1
- 被引次数: 0