摘要
为合理控制高速公路改扩建施工时开挖临空面后的路基稳定性和行车安全,通过建立有限元仿真模型,全面分析了临空面开挖高度、车辆荷载作用位置以及路基土质对开挖临空面路基工作状态的影响,对粘性土、砂性土和碎石土3种不同土质的路基、不同工况条件下的开挖临空面路基稳定系数进行了计算,在此基础上提出了高速公路改扩建路基开挖临空面安全控制标准。结果表明:临空面开挖高度和荷载作用位置对路基稳定性影响较大,临空面高度应控制在2.0m内,路侧安全距离应为1.5～2.0m;路基土质对路基稳定性影响相对较小,粘性土路基稳定性最好,依次是砂性土和碎石土;根据路基稳定系数的差异性,将路基高度分为:小于1.0m,1.0～1.5m,1.5～2.0m,2.0～3.0m和3.0～3.5m这5个等级,以稳定系数1.80为控制指标,制定了路基开挖临空面安全控制标准。
In order to reasonably control subgrade stability and driving safety after excavating the free face of subgrade in the freeway rebuilding,the finite element simulation model was established,the effect of the excavation free face height,the vehicle load acting position and the soil property of the old subgrade on the working condition of subgrade were comprehensively analyzed.The stability coefficient of three different kinds of engineering conditions including cohesive soil,sandy soil and gravelly soil was calculated.On the basis of the above results,the safety controlling standard on the excavating free face of the highway rebuilding subgrade was finally put forward.The results show that the stability of the subgrade is impacted largely by the height of the excavating free face of subgrade and the vehicle loading position.The height of the excavating free face of subgrade should be controlled within 2.0 m,the road side safe distance of the excavating free face should be from 1.5 m to 2.0 m.The effect of the kinds of subgrade soil on the the stability of the subgrade is relatively small,the stability of cohesive soil is the best,followed by sandy soil and gravelly soil.On the basis of the difference of the stability coefficient,the height of subgrade is divided into five grades： less than 1.0 m,from 1.0 m to 1.5 m,from 1.5 m to 2.0 m,from 2.0 m to 3.0 m and from 3.0 m to 3.5 m,the safe controlling standard of excavating free face can be established by using the stability coefficient 1.80 as control index.4 tabs,8 figs,10 refs.
出处
《长安大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2012年第2期16-21,共6页
Journal of Chang’an University(Natural Science Edition)
基金
天津市交通科技项目(2010-33)
关键词
道路工程
高速公路改扩建
路基
开挖临空面
安全控制标准
有限元法
road engineering
freeway rebuilding
subgrade
excavating free face
safety controlling standard
finite element method
