【作者】 韩伟平；

【导师】 孙建生；

【作者基本信息】 太原理工大学 ， 水工结构工程， 2007， 硕士

【摘要】 随着经济的高速发展，地下埋涵广泛应用于水利、公路、铁路等工程，占用工程投资相对较多，且工程量大。文献表明，涵洞在运营中常出现各种病害，其原因主要有两个：一是垂直土压力的计算值偏小；二是施工质量问题。目前垂直土压力的计算公式很多，但都存在一定的局限性。本文以室内试验为基础，结合有限元数值模拟和理论分析，对上埋式和高填方沟埋式涵洞土压力的计算进行了系统、深入的研究和分析。本论文所作的研究工作和得出的主要成果如下：(1)本文以刚性地基和砂性填土条件下的刚性箱涵为研究对象，通过模型试验和数值模拟计算，研究分析了槽底宽度为2倍洞径时的不同坡度以及边坡为直坡时不同槽宽条件下的涵洞土压力随填土高度的变化规律。研究结果表明，在各种边界条件下，当填土达到一定高度后，涵洞土压力随高度的变化规律不是线性的，而是非线性变化的。(2)上埋式涵洞与沟埋式涵洞的土压力系数与H／B有关，对于上埋式涵洞，垂直土压力系数K_v随着H／B的增加先升后降，且K_v大于1，最大值达到1.45；水平土压力系数K_h要大于按主动土压力计算的数值。对于沟埋式涵洞，垂直土压力系数K_v随着H／B的增加也是先升后降，在填土达到一定高度后，K_v小于1，水平土压力系数K_h小于按主动土压力计算的值。(3)沟埋式涵洞土压力分布规律随着开挖边坡的变缓、沟槽宽度的增大，垂直及侧向土压力逐渐增大。(4)针对现有设计规范中对沟埋式涵洞顶垂直土压力计算公式的不足，本论文通过理论分析、数值模拟计算和室内试验验证的方法，进行了涵洞土压力施工分层填筑模拟计算，取得了一定的成果，可以应用在实际工程建设中。更多还原

【Abstract】 With national economy developing by leaps and bounds, the culvert is widely used in water conservancy, highway, railway, etc .It can be mainly divided into two parts: channel-buried culvert and positive buried culvert. However, because lack of the reasonable earth pressure theory for design of these culverts, some of them fail in the period of construction or after completion of work for using smaller size of structure, in some case over big size of culvert structure are designed to be bear the uncertain pressures on the culverts and led to more cost. Based on the occasion above, the earth pressure theory and the method of load reduction are studied through model test and numeric simulation to find a reasonable earth pressure theory for the culverts beneath the high fill. The fruits of research in the thesis as follow:(1)A series of testing about stiff rounded culvert in the house have been carried on based on the stiff foundation and sand soil. Slope of trough wall; the condition of positive buried culvert. The result involves the earth pressure on the top of culvert, the lateral earth pressure and the displacement of the earth with the different height of backfill. The test results show the principle of variation of pressures on culverts beneath high fill is similar, it is that, even if the embankment is filled up to a higher height, the earth pressures can still partly transfer to the top of culvert, as a result the pressures on the culvert increase nonlinearly with the variation of height of fill and further the pressures.(2)There is connection between channel-buried culvert and positive buried culvert. Along with the increase of H/B, channel-buried culvert grow positive buried culvert. With the increase of H/B, positive coefficient of vertical soil pressure, K_v, decreases before ascend. K_v is above 1, the max of K_v is 1.45.Positive coefficient of horizontal soil pressure, K_h,is above the value by active earth pressure. With the increase of H/B, positive coefficient of vertical soil pressure, K_v, decreases before ascend. K_v is less than 1, positive coefficient of horizontal soil pressure, K_h, is less than the value by active earth pressure.(3)As the decrease of the slope and the increase of the width of the trough, that is to say, the slope of backfill is less than 1:1 or the width of the trough is four times than of the width of the span of culvert, the distribution of the channel-buried culvert is similar with that of positive buried culvert.(4)The theory of, so a new calculation model of earth pressure has been established in the paper, which also includes the formula of calculating the earth pressure of channel-buried culvert with the rectangular section and trapeze form the theory of M-S has been modulated. There is a conclusion that when the height of backfill is not tall, tall distribution of perpendicular earth pressure of channel-buried culvert is similar with that of positive buried culvert.更多还原