摘要
桩网路基由于其施工工期短和沉降变形小等优点在中国铁路和公路建设中得到了广泛的应用。为研究桩网路基中土拱效应的机理和影响因素,采用非连续变形分析方法(discontinuous deformation analysis, DDA),通过改变路基高度、桩间净距和土工格栅参数建立了九种不同模型。结果表明:数值结果与实验结果吻合良好,验证了非连续变形分析方法在模拟路基桩网结构土拱效应上的可行性;随着路基高度的增加,土拱产生的作用逐渐显著,等沉面高度稳定为0.8~0.85倍桩间净距;桩间净距对桩土应力比峰值时刻有明显影响,随着桩间净距的减小,桩顶接受来自路基荷载传递的压力增大,桩土应力比达到峰值的速度加快。桩间净距的减小会导致等沉面高度的下降;加入土工格栅后,桩网结构所产生的桩土应力比与未加入土工格栅的相比更大,说明土工格栅可有效提高路基强度。
Roadbeds of pile network have been widely used in railroads and highways construction in China due to their advantages such as short construction period and minimal settlement deformation.A discontinuous deformation analysis method(DDA)was used to study the mechanism and influencing variables of soil arch effect in the network roadbed.Nine different models were established by changing the roadbed height,inter-pile clearance and geogrid parameters.The results show these as follows.The numerical results are in good agreement with the experimental results,which verifies the feasibility of the discontinuous deformation analysis method in simulating the soil arch effect in the roadbed pile network structure.The influence of soil arch production becomes increasingly noticeable as the height of the roadbed rises,and the height of the equal sink surface stabilizes at 0.8~0.85 times the inter-pile clearance.The peak moment of the pile-soil stress ratio is clearly influenced by the net distance between piles;as this distance decreases,the pressure on the pile top receiving the load transfer from the roadbed rises and the peak speed of the pile-soil stress ratio accelerates.The reduction of the net distance between piles will lead to the decrease of the height of the surface.The pile-soil stress ratio generated by the pile network structure after the addition of the geogrid is greater compared with that without the geogrid,indicating that the geogrid can effectively improve the strength of the roadbed.
作者
刘启清
李诚豪
张凌之
夏斌
靳昆
马建军
黄林冲
LIU Qi-qing;LI Cheng-hao;ZHANG Ling-zhi;XIA Bin;JIN Kun;MA Jian-jun;HUANG Lin-chong(Guangdong Zhuzhao Railway Co.,Ltd.,Guangzhou 510000,China;School of Civil Engineering,Sun Yat-sen University,Zhuhai 519082,China)
出处
《科学技术与工程》
北大核心
2024年第7期2917-2926,共10页
Science Technology and Engineering
基金
广东珠肇铁路有限责任公司项目(珠肇(江机)(服)合(2022)003)。
关键词
非连续变形分析法
路基高度
桩间净距
桩网路基
土拱效应
discontinuous deformation analysis
height of roadbed
inter-pile clearance
roadbed of pile network
soil arch effect
