公路高填方涵洞土压力变化规律及计算方法研究

通过模型试验研究了狭窄沟谷沟心设涵、宽坦地形沟谷沟心设涵和岸坡脚设涵三种边界条件下高填方涵洞涵顶土压力随填土高度变化的规律,以及高填方涵洞的拱效应。试验结果表明,涵顶填土达到一定高度以后,在涵顶上方将产生拱效应,使涵洞顶上的土压力小于理论土压力。但由于高填方涵洞上方路基填料的特点,这种拱效应具有不稳定性,使涵顶土压力随填土高度成非线性变化增加。根据高填方涵洞的土压力变化规律及拱效应特点,提出了计算高填方涵洞非线性土压力计算理论和方法,得出三种边界条件下的非线性土压力计算公式,并通过算例证明了应用该公式计算高填方涵洞土压力的合理性。成果对高填方涵洞土压力计算、结构设计有应用参考价值。

A STUDY ON THE EARTH PRESSURE THEORY FOR HIGH FILL CULVERTS

The principle of earth pressure variation and the earth pressure theory for high fill culverts located different topography boundary conditions are studied in the paper. The earth pressures on culvert and arching effects are studied with model testing,to determine the principle of earth pressure variation and the factors that influence the earth pressure on high fill culverts. The test results show,as the earth embankment is filled higher,the arching action will take place above the culvert,and as a result the earth pressures on the culvert are less than the theoretical earth pressures and vary non-linearly with the height of fills. It is also confirmed in the experiment that the earth pressure can be indirectly affected by topography boundary conditions. Because of the filling is different from the insitu rock,the arching action above the culvert is unstable. Based on the principle of earth pressure variation,a non-linear earth pressure theory for high fill culvert is presented and an example is given to prove the non-linear earth pressure theory is a more suitable theory for high fill culverts.