地震荷载作用下双级加筋土挡墙破坏机理研究

发布时间：2018-08-13 17:50

【摘要】：目前双级加筋土挡墙已经广泛应用于工程实践中,而汶川地震中破坏的双级加筋土挡墙的破坏机理还未明晰,双级加筋土挡墙的动力性能有待深入研究,关于双级加筋土挡墙在高烈度区的抗震设计方法在我国的相关规范中没有具体给出。有鉴于此,本文以汶川地震中破坏的双级加筋土挡墙为研究对象,开展了双级加筋土挡墙的静、动力数值模拟工作,在此基础上讨论了不同参数对双级加筋土挡墙静、动力响应的影响,主要成果与结论如下:(1)静力条件下,汶川地震中破坏的双级加筋土挡墙稳定较好,挡墙水平变形以及筋材应变很小;按照规范计算单级加筋土挡墙水平土压力的方法计算得到的墙背水平土压力与数值模拟得到的双级加筋土挡墙的墙背水平土压力有所不同,规范计算值整体上偏大。(2)汶川地震中破坏的双级加筋土挡墙由于遭受了峰值加速度为0.4g的地震作用,超过了其抗震设防标准,因此过大的变形导致了挡墙的破坏。(3)在高烈度区,通过增大面板厚度和填土内摩擦角来限制双级加筋土挡墙水平变形和沉降变形的效果不明显,因此在高烈度地震区通过增大面板厚度和填土内摩擦角来提高双级加筋土挡墙的抗震性能不可行。(4)在高烈度区,增大平台宽度不能改善双级加筋土挡墙的水平变形,但是在控制上级挡墙的沉降变形方面有明显的效果。(5)地震波类型对双级加筋土挡墙的动力响应有明显的影响,因此对于拟建的重大工程,应该输入不同类型的地震波来分析挡墙可能发生的动力响应。(6)在高烈度区,具有一定坡角的双级加筋土挡墙的水平变形和沉降变形较小,抗震性能优于直立式双级加筋土挡墙,因此在高烈度区进行高大加筋土挡墙的抗震设计时,建议采用具有一定坡角的双级加筋土挡墙形式。
[Abstract]:At present, two-stage reinforced earth retaining wall has been widely used in engineering practice, but the failure mechanism of two-stage reinforced earth retaining wall destroyed in Wenchuan earthquake is not clear, and the dynamic performance of two-stage reinforced earth retaining wall needs to be deeply studied. The aseismic design method of double reinforced earth retaining wall in high intensity area is not given in the relevant codes of our country. In view of this, the static and dynamic numerical simulation work of two-stage reinforced earth retaining wall is carried out in this paper, which is damaged in Wenchuan earthquake. On the basis of this, the static state of two-stage reinforced earth retaining wall with different parameters is discussed. The main results and conclusions of the dynamic response are as follows: (1) under the static condition, the two-stage reinforced earth retaining wall destroyed in Wenchuan earthquake is stable, the horizontal deformation of retaining wall and the strain of reinforced material are very small; The horizontal earth pressure on the back of the wall is different from the horizontal earth pressure on the back of the double reinforced earth retaining wall obtained by numerical simulation according to the method of calculating the horizontal earth pressure of the single reinforced earth retaining wall. The calculated value of the code is on the whole larger. (2) the damage of the two-stage reinforced earth retaining wall in Wenchuan earthquake is due to the earthquake action of 0.4g peak acceleration, which exceeds its seismic fortification standard, so the excessive deformation leads to the destruction of the retaining wall. (3) in the high intensity area, the damage of the retaining wall is caused by excessive deformation. The effect of horizontal deformation and settlement deformation of double reinforced earth retaining wall is not obvious by increasing the thickness of the face plate and the friction angle of the filling soil in order to limit the horizontal deformation and the settlement deformation of the double-stage reinforced earth retaining wall. Therefore, it is not feasible to increase the seismic performance of two-stage reinforced earth retaining wall in high intensity seismic region by increasing the thickness of face plate and the friction angle of fill. (4) in the high intensity area, increasing the width of platform can not improve the horizontal deformation of two-stage reinforced earth retaining wall. But it has obvious effect in controlling the settlement and deformation of the superior retaining wall. (5) the type of seismic wave has obvious influence on the dynamic response of the double-stage reinforced earth retaining wall, so for the important project to be built, Different types of seismic waves should be input to analyze the dynamic response of the retaining wall. (6) in the high intensity region, the horizontal deformation and settlement deformation of the double-stage reinforced earth retaining wall with certain slope angle are smaller, and the seismic performance is better than that of the vertical double-reinforced earth retaining wall. Therefore, in the seismic design of high reinforced earth retaining wall in high intensity area, it is suggested that the double reinforced earth retaining wall with certain slope angle should be adopted.
【学位授予单位】：防灾科技学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU476.4

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