摘要
为系统研究冲击碾压过程中松散堰塞坝料的细观密实机制,基于自行设计的可视化冲击碾压模型装置及粒子图像测速技术,研究了不同冲击碾压参数对堰塞坝料地基的表面变形、内部变形及颗粒位移规律的影响。试验结果表明,冲击碾压加固过程是冲击和碾压两者共同作用,由于水平冲击作用,冲击点下方地基的变形具有非对称性。“高速轻轮”的施工参数会强化冲击效果,弱化碾压效果,造成地基表面平整性差。堰塞坝料冲击轮加固过程中的最大位移发生在三边形冲击轮圆弧面较平滑处与土体接触时,随后由于模型冲击轮重心上升,地基出现部分弹性回弹。提高冲击轮的牵引速度能够促进冲击能量向深层传递,但水平影响宽度有限;提高冲击轮的质量则能促进能量向两侧水平方向传递,但影响深度有限。对于模型试验的易贡堰塞坝料地基,冲击碾压最佳牵引速度约为0.75 m/s。结果可为堰塞坝料地基的冲击碾压浅层加固提供理论依据。
In order to systematically study the densification mechanism of landslide dam material during rolling dynamic compaction,based on the self-designed model device for rolling dynamic compaction and particle image velocimetry technology,the effects of different construction parameters on the deformation and particle displacement of the landslide dam material foundation were studied.The test results showed that the rolling dynamic compaction process is a combination of impact and rolling.Due to the horizontal impact,the deformation of the foundation under the impact point is asymmetric.The combination of"high speed and low-weight roller"construction parameters would improve the impact effect,and weaken the compaction effect,resulting in poor surface smoothness of the foundation.The maximum displacement during the reinforcement occurred when the arc surface of the triangular impact wheel was in contact with the soil.Afterwards,due to the rise of the center of the impact wheel,the foundation appeared partially elastical rebound.The increase of roller speed promotes the impact energy transfer to the deeper depth,but the improvement width is limited.The increase of roller weight promotes energy transfer to both horizontal sides,but the improvement depth is limited.For the Yigong landslide dam material foundation in the model test,the optimal towing speed for the rolling dynamic compaction is about 0.75 m/s.The results could provide a theoretical basis for the reinforcement of impact rolling of the shallow layer of landslide dam foundation.
作者
李文炜
占鑫杰
王保田
朱群峰
许小龙
左晋宇
王家辉
LI Wen-wei;ZHAN Xin-jie;WANG Bao-tian;ZHU Qun-feng;XU Xiao-long;ZUO Jin-yu;WANG Jia-hui(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China;Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing,Jiangsu 210029,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing,Jiangsu 210029,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第8期2297-2307,共11页
Rock and Soil Mechanics
基金
国家重点研发计划(No.2018YFC1508504)
南京水利科学研究院中央级公益性科研院所基本业务费(No.Y323002)。
关键词
堰塞坝料
冲击碾压
细观机制
颗粒运动
位移
landslide dam material
rolling dynamic compaction
meso-mechanism
particle motion
displacement
作者简介
第一作者:李文炜,男,1996年生,博士研究生,主要从事粗颗粒土力学特性、地基处理和土体固化方面的研究工作。E-mail:180804010002@hhu.edu.cn;通讯作者:占鑫杰,男,1986年生,博士,高级工程师,主要从事特殊土与软弱土地基处理、基础工程和环境岩土工程方面的研究工作。E-mail:xjzhan@nhri.cn。
