类岩材料非圆孔定向胀裂特征研究  

Study on Characteristics of Directional Expansion Cracking Behavior of Rock-Like Material with a Non-Circular Hole

作　　者：范祥[1,2] 李龙 黄旭飞 曹校勇 谢永利[1] Fan Xiang;Li Long;Huang Xufei;Cao Xiaoyong;Xie Yongli(School of Highway,Chang'an University,Xi'an 710064,P.R.China;CCCC First Highway Consultants Co.Ltd.,Xi'an 710075,P.R.China)

机构地区：[1]长安大学公路学院,西安710064 [2]中交第一公路勘察设计研究院有限公司,西安710075

出　　处：《地下空间与工程学报》2023年第3期793-803,共11页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学青年基金(41807241);中国博士后科学基金(2021M693544);长安大学中央高校基本科研业务费专项资金(300102211205)。

摘　　要：采用自行设计的劈裂器,对含有非圆孔混凝土试样进行了胀裂试验,研究了不同孔洞形状试件破坏荷载特征、裂纹扩展规律及孔周应力分布情况。结果表明:与圆形孔洞试件相比,椭圆孔、矩形孔和菱形孔试件峰值荷载均显著降低,荷载减小比例为28.2%~70.3%;椭圆孔洞、矩形孔洞和菱形孔洞对裂纹的萌生均产生了导向作用,椭圆孔洞与菱形孔洞对裂纹的导向作用随着长短轴(对角线)比值的增大而增强,而矩形孔洞导向作用随边长比值的改变变化不显著;从裂纹导向效果来看,菱形孔洞优于椭圆孔洞,椭圆孔洞优于矩形孔洞;改变孔洞形状产生了明显的拉应力集中现象,椭圆孔洞长轴端点拉应力集中程度随着长短轴比值的增大而增大;矩形孔洞4个尖端拉应力集中程度随着边长比值的增大呈现出先减小再增大的规律;菱形孔洞拉应力集中程度随着对角线比值的增大表现出先增大再减小的变化趋势。The dilatancy test of concrete samples with non-circular holes was carried out by using a self-designed splitter.The failure load characteristics,crack propagation law and stress distribution around the holes of specimens with different hole shapes were studied.The results show that:compared with the circular hole specimens,the peak load of the elliptical hole,rectangular hole and diamond hole specimens is significantly reduced,and the load reduction ratio is 28.2%~70.3%.Elliptic,rectangular and rhomboid holes all have a guiding effect on the crack initiation.The guiding effect of elliptic and rhomboid holes on the crack initiation increases with the increase of the ratio of the long and short axes(diagonal lines),while the guiding effect of rectangular holes does not change significantly with the change of the ratio of the side length.In terms of crack guiding effect,rhomboid holes are better than elliptic holes,and elliptic holes are better than rectangular holes.The change in the shape of the cavity produces the obvious tensile stress concentration phenomenon,and the degree of tensile stress concentration at the long axis of the elliptical cavity increases with the increase of the ratio of the short axis to the long axis.The degree of tensile stress concentration at the four tips of the rectangular hole decreases first and then increases with the increase of the ratio of side length.The tensile stress concentration of rhombic hole increases first and then decreases with the increase of diagonal ratio.

关 键 词：定向胀裂 扩展有限元 裂纹扩展 孔洞形状 应力分布 

分 类 号：TU458[建筑科学—岩土工程]