50
DOI:10.7672/sgjs2016110050
施工技术
CONSTRUCTION TECHNOLOGY
强夯法在皖江软土路基处理中的应用
袁海平1,2，韩治勇1石贤增3，浦玉炳3，朱大勇
2016年6月上第45卷第11期
（1.合肥工业大学土木与水利工程学院，安徽合肥230009；2.中国矿业大学煤炭资源与安全开采国家
重点实验室，江苏徐州221116；3.合肥市市政设计院有限公司，安徽合肥230041）
[摘要]软土路基因其土层分布复杂，物理力学性质差异较大，加固路基土体成为市政道路处理的迫切需要。依托皖江城市带市政道路处理工程，分析了各遍强夯下的加速度效应及夯坑沉降规律，并用荷载试验评价了强夯路基的处理效果。研究结果表明，峰值加速度受夯点距离的影响，在近距离处峰值加速度较大，且衰减较快；随着距离的增大，其值逐渐减小，且衰减量较小，地表加固距离大约为30m，竖直方向加固深度为6m左右；夯击次数对夯沉量有重要影响，超过一定击数后，土体得不到加固；荷载试验得到了路基承载力特征值>120kPa，超过了其设计承载力特征值。
【关键词］】公路工程；路基；强夯；软土；加速度；沉降；承载力
【中图分类号］U416.1
【文献标识码］A
[文章编号］1002-8498(2016)11-0050-05
Application ofDynamicCompactionMethodin Soft Soil Subgrade
TreatmentinWanjiangRegion
Yuan Haiping'2,Han Zhiyong',Shi Xianzeng",PuYubing',Zhu Dayong(1. School of Ciwil Engineering, Hefei Unirersity of Technology,Hefei,Anhui 230009, China ;
2. The State Key Laboratory of Coal Resources and Mine Safety, China Unirersity of Mining and Technology, Xuzhou,Jiangsu 221116, China; 3. Hefei Municipal Design Institute Co. , Lid. ,Hefei,Anhui 230041,China
Abstract : The distribution of soil in soft soil subgrade is complex. And physical and mechanical properties are of great difference. Therefore, reinforcement of subgrade soil becomes the urgent need of municipal road treatment. Relying on municipal road engineering in Wanjiang urban area, the effect of acceleration and law of tamping pit settlements is analyzed each time under dynamic compaction. The treatment effect of dynamic compaction was evaluated based on the load test. Research results show that under the influence of distance of tamping points peak acceleration is larger at close range and attenuation is faster. With the increase of distance, its value decreases gradually, and the attenuation is also small. The reinforcement distance on the surface is about 3Om and reinforcement depth in vertical direction is about 6m. Tamping times have important effects on tamping pit settlements. After more than certain numbers, the soil can't be reinforced. The characteristic value of subgrade bearing capacity is more than 120kPa according to load test. It is more than the subgrade characteristic value of design bearing capacity.
Key words : road construction ; subgrade ; dynamic compaction; soft soil; acceleration; settlement; bearing capacity
1低能量强夯基本原理
强过程中，夯锤产生的能量由地表向周围传
*国家自然科学基金项目（51004007）；煤炭资源与安全开采国家重点实验室开放研究基金资助项目（12KF06）：住建部科技计划资助项目（2014-K5-002）；安徽省建设行业科技计划资助项目（2014YF-12）[作者简介］袁海平，副教授，硕士生导师，E-mail：seapie@hfut. edu.
[通讯作者］韩治勇，硕土研究生，E-mail1172385925@qq-com[收稿日期】2015-03-19
递，各位置强夯产生的振动效应不同，因此不同程度地加固软土地基，地基加固如图1所示。
夯锤与地基之间反复接触和分离的过程类似于碰撞原理，将夯锤视为刚体，其运动方程为：
mheg +R.(t) = mhw(t)
(1)
式中：m为夯锤质量：R。（t）为地基与夯锤接触面的动接触压力；（t）为夯锤的加速度。