涵顶-涵侧减载条件下高填方箱涵施工期受力特性  

Stress characteristics of high-fill box culvert with soft layers placed on the top and sidewall during construction

作　　者：任一青 陈保国[1] 任国卿 杨振忠 徐方[1] REN Yi-qing;CHEN Bao-guo;REN Guo-qing;YANG Zhen-zhong;XU Fang(Faculty of Engineering,China University of Geosciences,Wuhan,Hubei 430074,China)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《岩土力学》2025年第4期1153-1162,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52178370)。

摘　　要：高填方箱涵顶部铺设柔性填料能够大幅降低涵顶土压力,但同时也导致涵侧水平土压力和摩擦力显著增大,这很可能引起新的结构病害。为了进一步改善高填方箱涵受力状态,通过模型试验研究涵顶-涵侧同时铺设柔性填料后箱涵受力特性和减载效果。采用模型试验探究了海绵和可发性聚苯乙烯板(expanded polystyrene board,EPS板)两种柔性减载时,涵顶、涵侧和基底土压力随填土高度的变化规律;并将土压力结果无量纲化处理后得到土压力系数,与既有柔性填料减载技术代表性研究成果进行对比分析,探讨涵顶、涵侧铺设柔性填料的减载效果。结果表明,在涵洞顶部和侧部同时铺设柔性填料能够有效改善箱涵的受力状态,涵顶和涵侧产生土拱效应,通过土拱将涵洞上部土压力转移到涵侧外部填土中,既明显缓解了涵顶土压力集中,又有效降低了涵侧水平土压力和基底压力。Laying soft materials on the top of high-fill box culverts can greatly reduce the vertical earth pressure on the top of the culvert.However,it also leads to a significant increase in horizontal earth pressure and friction on the sidewall of the box culvert,which is likely to cause new structural diseases.In order to improve the stress state of high-fill box culvert,this paper studied the stress characteristics and load reduction effect of box culvert with laying soft materials on the top slab and sidewalls of the culvert through model test.The variation laws of earth pressure on the culvert top,sidewall,and the foundation contact pressure with the fill height were explored by considering two different soft materials(i.e.,Sponge and expanded polystyrene(EPS)board).Moreover,the earth pressure coefficients were obtained by the dimensionless of the earth pressure data,which were compared with the existing representative research results of the culverts with laying soft materials on the culvert structures,and the load reduction effect of laying soft materials both on the top slab and sidewalls was proved.The research results show that laying soft materials on the top slab and sidewalls of the culvert can effectively improve the stress state of the box culvert.The soil arch effects generate on the culvert top and sidewalls,the vertical load on the culvert top is transferred to the outside fill of the culvert.Thus,it not only significantly alleviates the earth pressure concentration on the culvert top slab,but also effectively reduces the horizontal earth pressure on the sidewall and the foundation contact pressure.

关 键 词：箱型涵洞 减载 模型试验 土压力 土拱效应 

分 类 号：TU432[建筑科学—岩土工程]