强夯置换处置山间软土地基的宏细观特性  

Macro and Micro Characteristics of Dynamic Compaction Replacement Treatment of Soft Soil Foundations in Mountainous Areas

作　　者：柳正 张向川 秦桂芳 李绍龙 聂如松[2] LIU Zheng;ZHANG Xiangchuan;QIN Guifang;LI Shaolong;NIE Rusong(Guizhou Road&Bridge Group Co.,Ltd.,Guiyang 550001,China;School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]贵州路桥集团有限公司,贵州贵阳550001 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《西北工程技术学报(中英文)》2025年第1期38-44,共7页Ningxia Engineering Technology

基　　金：国家自然科学基金项目(51878666);贵州路桥集团有限公司技术开发项目(LATJ-13-KY01)。

摘　　要：依托贵州六枝至安龙高速公路某山区软土地基处理工程,对强夯置换法的夯沉量开展了现场实测。在此基础上,构建了强夯置换法处理软土地基的离散元模型,根据实际模拟了强夯置换施工过程,揭示了软土地基强夯置换墩的形成机理。结果表明,累积夯沉量随着夯击次数的增加呈近似线性增加。单击夯沉量和累积夯沉量与夯击能密切相关,夯击能越大,夯沉量越大,要达到相同的夯沉量,夯击能大的夯击次数少,夯击能小的夯击次数就多。强夯过程中,每击的夯沉量随着填料次数的增加逐渐减小,当填料8次以后,坑底夯沉量与夯击次数的关系曲线变化很小。夯坑底部软土竖向动应力峰值达339kPa,跳锤后动应力迅速下降,在0.1s时接近夯前水平,随后夯锤回落,竖向应力上升并稳定在110kPa左右。最大置换宽度随着填料次数的增加呈近似线性增大,填料次数增至4次以后,最大置换宽度大于最大置换深度,强夯结束时,最大置换宽度约为最大置换深度的1.46倍。This study relies on a soft soil foundation treatment project in a mountainous section of the Liuzhi to Anlong Expressway to test the settlement due to dynamic compaction replacement.A numerical model for dynamic compaction replacement treatment of soft soil foundation was constructed,and the construction process of dynamic compaction replacement of soft soil foundation was simulated based on on-site conditions,revealing the formation mechanism of dynamic compaction replacement piers in soft soil foundation.The results indicate that the cumulative compaction settlement increases approximately linearly with the increase of compaction blows.The single compaction settlement and cumulative compaction settlement are closely related to the compaction energy.The greater the compaction energy,the greater the compaction settlement.To achieve the same compaction settlement,the higher the compaction energy,the fewer the compaction blows,while the lower the compaction energy,the more the compaction blows.During the dynamic compaction process,the settlement per impact gradually decreases as the number of fill placements increases.After 8 fills,the relationship curve between the bottom settlement of the pit and the number of impacts changes very little.The peak vertical dynamic stress at the bottom of the compaction pit reaches 339 kPa,rapidly decreasing after the the hammer is lifted,approaching the pre-compaction level 0.1 s.Subsequently,as the hammer falls,the vertical stress rises and stabilizes around 110 kPa.The maximum replacement width increases approximately linearly with the number of fillers.After the number of placements exceeds 4,the maximum replacement width is greater than the maximum replacement depth.At the end of dynamic compaction,the maximum displacement width is about 1.46 times the maximum replacement depth.

关 键 词：道路工程 强夯置换 碎石墩 置换范围 大变形 动力响应 离散元法 

分 类 号：TU472[建筑科学—结构工程]