Research On The Earth Pressure Calculation Theory And Structure For The Culvert Under High Fill

The Culvert under High Fill is important in our country mountainous area highwaydrainage structures. With the continuous improvement of our country mountainous areahighway grade, increasing the number of high fill culvert, but high fill culvert structure designis still a lack of reasonable theoretical guidance, lead to part of the culvert due to overlyconservative and not economy, part of the culvert and the disease due to small size. In thispaper, through model test, numerical simulation and field engineering test, with different spanand different packing stone content of high fill culvert earth pressure to study the change rule,in order to find out reasonable high fill culvert earth pressure calculation formula of thespecific research contents and results are as follows:①Studied the soil arch effect of high fill culverts. Through model test and numericalsimulation, we get different span and different packing stone content of high fill culvert earthpressure changing with filling height. Results confirm the high fill culvert top does form thesoil arch effect, when the filled soil after reaching a certain height, the lateral earth pressure ofthe culvert top and culvert of soil column method is less than the theoretical calculation values;At the same time, the soil arch effect of high fill culvert has the characteristics of instability,with the increase of filling soil height, there will still be part of the earth pressure is passed onto the culvert.②Analyzed the different span length under the condition of high fill culvert culvertschange laws of earth pressure. Model test and numerical simulation results of the mutualverification, found that with the increase of span length of the culvert, high fill culvert topculvert earth pressure will increase, and contain the outer earth pressure will decrease; Spansmall culvert, the top soil is easier to form soil arch effect.③Analyzed the different packing of high fill culvert earth pressure change rule. Themodel test and numerical simulation results of the mutual verification, found that with theincrease of filler in the stone content, high fill culverts culvert top soil pressure increase is notobvious, and contain a outside earth pressure will increase obviously; When packing the stonecontent is30%~70%, the filler containing a high percentage of stone in the culvert, the topsoil is easier to form soil arch effect, when packing the stone content in more than70%, withthe increased amount of stone instead to make it more difficult to form the soil arch effectculvert top soil.④high fill culvert earth pressure calculation formula is put forward. High fill culvertsunder different conditions according to the rule of variation of soil pressure, based on the dataobtained by model test and numerical simulation of regression, high fill culvert earth pressurecalculation formula is put forward, and the formula with the field test results and comparing theexisting typical earth pressure calculation theory, demonstrates the reliability of high fillculvert earth pressure calculation formula.⑤high fill culvert earth pressure calculation formula is put forward. The applicationscope of High fill culvert soil pressure calculation formula can only be used for wide terrain,under the condition of rigid foundation, filling more than16m slab culvert, when fill less than16m, still using the method of soil column theory calculation of earth pressure on culvert top.At the same time, should also be combined with the engineering practice of the culvert andpacking stone content models on the use of high fill culvert, adjust the height of the soilpressure calculation formula in order to obtain the most economic and reasonable effect.