不同缝面形态下诱导缝开裂效果对比研究

发布时间：2018-10-20 15:15

【摘要】：一些采用径向扭缝的碾压混凝土拱坝工程中,出现了诱导缝周边坝体混凝土开裂而诱导缝本身未张开的现象,因此需定量分析不同空间形态缝面对诱导缝开裂的影响效果。根据碾压混凝土拱坝应力变化特点以及诱导缝开裂变化规律,本文拟定含不同缝面空间形态的有限大平板和圆筒拱坝算例,利用虚拟裂纹闭合法和Richard脆性断裂准则获取空间缝面等效应力强度因子,研究缝面应力强度因子随缝面夹角的变化规律;通过对归一化后的应力强度因子求倒数,获取不同缝面夹角条件下诱导缝等效强度的修正系数即缝面空间形态影响因子,以反映不同缝面空间形态下诱导缝开裂效果。研究表明,随着缝面夹角的不断增大,缝面越不容易张开,这就意味着缝面的等效强度在逐渐增大。因此,在实际碾压混凝土拱坝设计中,诱导缝应尽量采用竖向垂直缝布置;若要布置成径向扭缝,则缝面夹角最大不宜超过10°。
[Abstract]:In some RCC arch dam projects with radial torsional joints, there is a phenomenon that the induced joints do not open due to concrete cracking around the joints, so it is necessary to quantitatively analyze the effect of different spatial joints on the induced joint cracking. According to the stress variation characteristics of RCC arch dam and the variation law of induced joint cracking, the examples of finite plate and cylindrical arch dam with different joint surface spatial form are worked out in this paper. Using virtual crack closure method and Richard brittle fracture criterion to obtain the equivalent stress intensity factor of space joint surface, the variation of stress intensity factor with the angle of joint surface is studied, and the inverse of the normalized stress intensity factor is obtained. The correction coefficient of the equivalent strength of induced joints under different joint angles is obtained to reflect the effect of induced joint cracking under different joint space shapes. It is shown that with the increasing of the angle between the joints, the more difficult the joint surface is to open, which means that the equivalent strength of the joint surface increases gradually. Therefore, in the design of RCC arch dam, the vertical joint should be arranged as far as possible, and the maximum angle of joint surface should not exceed 10 掳if the joint is arranged as radial torsional joint.
【作者单位】：中国水利水电科学研究院结构材料研究所;
【基金】：国家自然科学基金项目(51779276,51579252) 国家重点研发计划项目(2016YFB0201003,2016YFC0401807) 国家重点基础研究发展规划项目(2013CB036406,2013CB035904)
【分类号】：TV544.921

【相似文献】