摘要
现行公路桥涵设计通用规范中的线性土压力理论不能准确反映非对称沟埋式涵洞结构的实际受力特性.结合现场试验和数值模拟研究了沟谷非对称设涵时,涵-土体系的受力状态和变形特性以及涵顶填土内部的土拱效应.讨论了偏载效应对涵-土体系受力和变形的影响.研究结果表明,涵顶填土达到一定高度后填土内部产生土拱效应,该土拱效应能够缓解涵顶的应力集中,但其具有不稳定性.现场试验和数值模拟得到的涵顶土压力均大于现行公路桥涵设计通用规范的计算结果,而且偏载效应对涵-土体系的受力状态和变形特性的影响也不容忽视.
The computation of the design load on culverts in the current Chinese General Code for Design of Highway Bridges and Culverts （CGCDHBC）is primarily based on the linear earth pressure theory, which cannot accurately reflect the changes in vertical loads on trench installation culverts. So the changes in vertical earth pressure and soil arching effect in the backfill for an unsymmetrical trench installation culvert are studied based on a full scale experiment and finite element （FE） simulation. The variation laws of foundation pressure and settlement are also analyzed. Meanwhile, the influence of eccentric load induced by an unsymmetrical trench installation on the interaction of a soil- structure system is discussed. Results show that soil arch is formed when the backfill on the culvert reaches a certain height. It can relieve the earth pressure concentration on the crest of the culvert, but it is instable. The earth pressures obtained by full scale experiment and numerical simulation are greater than those calculated by the current CGCDHBC method. The eccentric load effect on the culvert has a significant influence on the stress states and deformation of the soil-structure system.
基金
Key Plan of Science and Technology of Hubei Provincial Communication Department(No.2005-361)
关键词
土与结构物作用机理
土拱效应
偏载效应
足尺试验
数值模拟
soil-structure interaction
soil arching effect
eccentric load effect
full scale experiment
numerical simulation
