碾压混凝土穿透型和边缘型诱导缝等效强度的试验研究  

Experimental study on equivalent strength for penetrated crack director and edge crack director in RCC

作　　者：张小刚[1] 宋玉普[1] 吴智敏[1] 

机构地区：[1]大连理工大学海岸及近海工程国家重点实验室结构分室,辽宁大连116024

出　　处：《混凝土》2004年第6期10-13,共4页Concrete

基　　金：国家自然基金项目(50179002)

摘　　要：　为了研究拱坝诱导缝强度特性,在两种尺寸的碾压混凝土长方体试件内埋设了相同削弱度的一片、两片穿透型诱导缝板和边缘型诱导板。对其进行的轴拉试验表明,在削弱度不变的情况下,诱导缝布置由一片改为两片对削弱断面的强度起到了很大的作用,如对于削弱度为0 342的试件,等效强度最大降低了36 5%。在相同尺寸和削弱度下,增大两片缝的间距,对降低等效强度也有很大的作用:当缝距b/a从2 69降低到1 92时,等效强度最大降低了26 5%。并给出了大型试件两块诱导片间距对等效强度的影响公式。这一实验结果表明实际大坝中合理布置诱导缝比单纯增加削弱度对降低诱导缝等效强度更有效。最后结合实际拱坝研究了边缘型诱导缝对断面强度的削弱作用,指出其等效强度随削弱度的变化是一凹曲线。Penetrated crack director and edge crack director were placed in RCC-cuboids specimens with divene size in ordr to study the strength property of crack director in RCC arch dam.Experimental data about the equivalent strength of the crack director are obtained from direct tension experiments towards the cuboid specimens.The experimental evidences reveal that the setting of two crack directors is more helpful to reduce the equivalent strength than one director,which has the same weakened variant as Hte former: for dte maximum weakaled variant 0.342,the max-decrease of equivalent strength is 36.5%.At the same time,the interval between two edges of crack derectors has great impacts on the valae of equivalent strength:as the interval reduce from 2.69 to 1.92,the equivalent strength fall 26.5%.The results of the experiment indicate that reasonable setting of crack director in arch dam is more effective to decrease the equivalent strength than only increase the weakened variant.At last the analysis about equivalent strength of edge crack director indicates that the equivalent strength is a concave line when α ranged from zero to one.

关 键 词：碾压混凝土 穿透型诱导缝 边缘型诱导缝 等效强度 轴拉试验 

分 类 号：TV313[水利工程—水工结构工程]