摘要
为探究高速黄土路基涵洞土压力分布特征,改进高填方涵洞结构设计,以山西省某拱涵为例,采用CANDE-2007有限元软件建立高填方涵洞数值分析模型,以涵洞设涵方式和填土高度为主要影响因素,揭示涵洞垂直土压力及沉降分布特征,分析不同填土高度下涵顶土压力系数变化,比较上埋式和沟埋式两种设涵方式涵洞涵顶土压力随填土高度变化特征,讨论设涵方式及土拱效应对涵洞应力的影响。在拱涵结构上部土体中布置土压力计,记录土体的实测土压力数据,并将数值模拟结果与实测数据结果相互验证。结果表明:涵洞中心与两侧土体的沉降明显不同,导致土拱效应的产生,是影响涵洞顶部垂直土应力变化的重要因素;2种设涵方式涵洞涵顶土压力随填土高度变化均呈线性增长趋势;填土高度大于5 m后,随填土高度增加,上埋式涵洞土压力系数呈现先急剧增加再缓慢降低的变化趋势,涵顶伴随应力集中;而沟埋式涵洞土压力系数随高度增加逐渐降低后趋于稳定,其涵顶所受垂直土压力减小;沟埋式涵洞中心沉降值总是大于同等高度下上埋式涵洞的中心沉降;现场监测与数值模拟对比,实测土压力大于数值模拟结果,工程中涵顶应力集中现象更明显。
To explore the earth pressure distribution characteristics of loess subgrade culvert on expressway and improve the structural design of high fill culvert,taking an arch culvert of Shanxi Province for example,a numerical analysis model of high fill culvert is established by using CANDE-2007 FE software.Taking the culvert setting method and filling height as the main influencing factors,the distribution characteristics of vertical earth pressure and settlement of the culvert are revealed,the variation of earth pressure coefficient at culvert top at different filling heights is analyzed,the variation characteristics of earth pressure at culvert top with filling height under the construction methods of buried culvert and trench culvert are compared,and the influences of culvert construction method and soil arching effect on culvert stress are discussed.The earth pressure gauge is embedded in the upper soil of the arch culvert structure to record the measured earth pressure data,and the numerical simulation result is verified with the measured data.The result shows that(1)the settlements of the soil in the culvert center is obviously different from that at both sides of the culvert,which leads to the soil arching effect and is an important factor affecting the vertical soil stress at the culvert top;(2)the earth pressure on the culvert top in the 2 culvert methods increases linearly with the filling height;(3)when the filling height is greater than 5 m,the earth pressure coefficient of the buried culvert increases sharply at first and then decreases slowly with the increase of the filling height,and the stress concentration occurs at the culvert top,while the earth pressure coefficient of trench culvert decreases and then tends to be stable with the increase of height,and the vertical earth pressure on the culvert top decreases;(4)the central settlement value of trench culvert is always greater than that of buried culvert at the same height;(5)comparing the field monitoring data with numerical simulation data,the measured earth pressure is greater than the numerical simulation result,and the stress concentration on the culvert top is more obvious.
作者
李晓旭
叶海林
金俊喜
苏和
张化杰
LI Xiao-xu;YE Hai-lin;JIN Jun-xi;SU He;ZHANG Hua-jie(Shanxi Transportation Survey&Design Institute Co.,Ltd.,Taiyuan Shanxi 030032,China;Research Institute of Special Engineering and Design,Beijing 100028,China;China University of Geosciences(Beijing),Beijing 100083,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2021年第8期37-43,共7页
Journal of Highway and Transportation Research and Development
关键词
道路工程
垂直土压力
数值模拟
现场监测
高填方涵洞
road engineering
vertical earth pressure
numerical simulation
in-situ monitoring
high fill culvert
