红黏土塑性混凝土防渗墙在坝基覆盖层中的应力变形数值模拟研究

发布时间：2018-07-10 18:15

本文选题：红黏土塑性混凝土防渗墙 + 覆盖层　；参考：《昆明理工大学》2017年硕士论文

【摘要】：土石坝为水利工程中最古老的一种坝形,在国内因其取材方便、施工简单被广泛应用,但大多数修建在上个世纪,由于施工技术及资金的限制,工程质量较差,目前多数带病运行,亟需进行除险加固。我国云南省有着大量的红黏土资源,是红黏土塑性混凝土的主要原料。本次模拟采用云南红黏土塑性混凝土防渗墙作为坝基防渗体,利用三维有限元分析软件对云南省石林县某水库进行了红黏土塑性混凝土防渗墙与两侧覆盖层的应力变形及防渗的数值模拟分析,计算中各分区均采用Duncan-eb模型,水位分别为校核洪水位、正常蓄水位及死水位,墙体厚度分别为0.3m、0.4m及0.5m,利用前处理软件HyperMesh进行建立模型、划分网格,利用非线性功能较强的有限元软件ABAQUS进行计算。计算中对分层填筑进行模拟、并考虑地应力平衡及网格划分的合理性及流固耦合的相互作用,保证数值模拟的精确性。对校核洪水位、正常蓄水位及死水位下0.3m、0.4m及0.5m厚防渗墙进行计算,分析对比各工况下防渗墙的应力情况、防渗效果及与覆盖层的变形协调性。计算结果显示,在坝基加入防渗墙后,坝体及防渗墙的应力变形值均在合理范围内,但防渗墙的墙顶及墙底处大主应力均发生不同程度的应力突变,经过对比分析判断,突变应力值未达到红黏土塑性混凝土的破坏值,理论上不会发生破坏。本文通过查阅大量的文献和研究,对斜墙下覆盖层中红黏土塑性混凝土防渗墙在不同水位和不同墙厚的工况下进行分析研究,主要结论如下:(1)在校核洪水位、正常蓄水位和死水位下,防渗墙的铅锤向的位移随着墙体厚度的增大而减小,各工况下协调性均在合理范围内,死水位下墙体铅垂向位移小于校核洪水位及正常蓄水位;顺河向位移最大值随着墙体厚度的增加而减小,且随着水位的下降,最大值发生高程点向墙顶偏移,且有向上游移动的趋势。(2)校核洪水位、正常蓄水位及死水位作用下,防渗墙顶部垂直应力值为墙底的50%-60%,随着水位的下降和墙厚的增加,防渗墙内部垂直应力值减小,有利于改善墙体内部应力不均的情况。(3)在校核洪水位、正常蓄水位及死水位作用下,各工况下墙体内部的大、小主应力均为压应力为主,其中大主应力只在墙体两端连接处出现极小部分的拉应力区,且数值极小。(4)在校核洪水位、正常蓄水位和死水位下,防渗墙厚度分别0.3m、0.4m和0.5m厚,浸润线均发生了不同程度的降低,且随着防渗墙厚度的增加,年渗漏量有减小的趋势。
[Abstract]:Earth rock dam is one of the oldest type of dam in water conservancy project. It is widely used in China because of its convenience. But most of it was built in the last century. Because of the construction technology and capital limitation, the quality of the project is poor. At present, most of the diseases run and need to be strengthened and strengthened. There are a large number of red clay resources in Yunnan province of China. The main raw material of the plastic concrete of red clay. This simulation uses the Yunnan red clay plastic concrete anti seepage wall as the dam foundation impervious body, and uses the three-dimensional finite element analysis software to carry on the numerical simulation analysis of the stress, deformation and seepage prevention of the red clay plastic concrete impervious wall and the two sides covering layer of a reservoir in Shilin County of Yunnan province. The Duncan-eb model is used in each area. The water level is checked for the flood water level, the normal water level and the dead water level. The thickness of the wall is 0.3m, 0.4m and 0.5m respectively. The model is set up by the pretreatment software HyperMesh, and the grid is divided by the finite element software ABAQUS, which has strong nonlinear function, and the layered filling is simulated in the calculation. Considering the rationality of geostress equilibrium and the rationality of grid partition and the interaction of fluid solid coupling, the accuracy of numerical simulation is ensured. The calculation of 0.3m, 0.4m and 0.5m thick impervious wall is carried out to check the flood water level, normal water level and dead water level, and to analyze and compare the stress situation of the impervious wall under various working conditions, the effect of seepage prevention and the deformation coordination with the cover layer. The calculation results show that the stress and deformation values of the dam and the impervious wall are in a reasonable range after the dam foundation is added to the dam, but the stress catastrophe of the main stress at the top of the wall and the bottom of the wall has been changed in varying degrees. After the comparison and analysis, the value of the catastrophe stress does not reach the damage value of the plastic concrete of the red clay, and it will not be damaged in theory. By consulting a lot of literature and research, this paper analyzes and studies the plastic concrete impervious wall in the overlay layer under the oblique wall under the conditions of different water level and different wall thickness. The main conclusions are as follows: (1) the displacement of the lead hammer of the impervious wall decreases with the increase of the thickness of the wall under the water level in the school, the normal water level and the dead water level. The vertical displacement of the wall lead under the dead water position is less than the check flood water level and the normal storage position under the dead water position. The maximum value of the downstream displacement decreases with the increase of the wall thickness, and with the decline of the water level, the maximum value shifts to the top of the wall and moves upstream. (2) check the flood water level, normal Under the action of water storage and dead water level, the vertical stress at the top of the impervious wall is 50%-60% at the bottom of the wall. With the decrease of water level and the increase of wall thickness, the value of vertical stress in the impermeable wall decreases, which is beneficial to improve the uneven stress inside the wall. (3) under the action of the water level in the school, the normal water level and the dead water level, the wall inside the wall is large under the various working conditions. The stress of the small main stress is mainly pressure stress, in which the main stress is only in the small part of the tensile stress zone at the end of the wall, and the value is very small. (4) the depth of the core flood, the normal water level and the dead water level, the thickness of the impervious wall are 0.3m, 0.4m and 0.5m, and the infiltration line has been reduced in varying degrees, with the increase of the thickness of the seepage proof wall. The annual leakage has a tendency to decrease.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV223.42

【参考文献】