围压作用对爆破裂纹空间形态影响的试验研究  

Experimental Study on Influence of Confining Pressure on Spatial Morphology of Blasting crack

作　　者：赵海洋[1,2] 陈大勇[3] 刘志远[1,2] 黄炳香[3] 金峰 黄燕飞[1,2] 赵兴龙[3] 邢岳堃 焦雪杰 ZHAO Hai-yang;CHEN Da-yong;LIU Zhi-yuan;HUANG Bing-xiang;JIN Feng;HUANG Yan-fei;ZHAO Xing-long;XING Yue-kun;JIAO Xue-jie(Research Institute of Petroleum Engineering,Sinopec Northwest Oilfield Branch,Urumqi 830011,China;Sinopec Key Laboratory for EOR of Fractured-vuggy Reservoirs,Urumqi 830011,China;State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国石化西北油田分公司石油工程技术研究院,乌鲁木齐830011 [2]中国石化缝洞型油藏提高采收率重点实验室,乌鲁木齐830011 [3]中国矿业大学煤炭资源与安全开采国家重点实验室,徐州221116

出　　处：《爆破》2022年第2期9-15,共7页Blasting

基　　金：十三五国家科技重大专项“缝洞型油藏堵调及靶向酸压工艺技术”(编号:2016ZX05014-005-003);国家自然科学基金青年项目(No.51604261)。

摘　　要：爆破裂纹的空间形态是进行爆破设计的理论依据。地下超深孔爆破炮孔处在围压作用之中,无爆破自由面,此种条件下爆破裂纹空间形态有待进一步的研究。采用4000 kN大型真三轴加载设备和煤矿许用导爆索分别提供围压静载和爆炸动载,并浇筑300 mm×300 mm×300 mm尺寸水泥砂浆立方体试块,采用的等效炸药量均为3 g,围压条件下试块加载的第一、第二、第三主应力分别为8.50 MPa、7.00 MPa、5.75 MPa,对比分析有、无围压两种条件爆破裂纹的空间形态差异。研究发现:围压条件下的爆破裂纹空间形态与拥有爆破自由面条件的爆破裂纹空间形态差异极大,四周拥有爆破自由面条件下试块爆破破碎为碎块,在块度尺寸L<100 mm和100 mm≤L≤200 mm范围内的破碎块度质量分别占试块总质量的30%和70%,其中大尺寸150 mm≤L<200 mm范围内的块度质量占比达到55.32%,但是数量较少,并且都产生于试块表面;围压条件下,在垂直于第二主应力方向产生一个以封孔器为中心对称的宏观破裂面,在试块的其它表面上产生了几条宏观裂纹。试块剖开后,在炮孔壁部产生微裂纹,在预先射孔方向的孔壁处产生明显的裂纹。The spatial morphology of blasting crack is the theoretical basis for a blasting design.The blasting hole of underground ultra-deep hole blasting is under the action of confining pressure,and there is no blasting free surface.Under such condition,the spatical morphology of blasting crack needs to be further studied.In order to study the influence of confining pressure on the spatial morphology of blasting crack,large scale 4000 kN true triaxial loading equipment and permitted detonating cord of coal mine are used to provide confining static load and explosive dynamic load respectively.For this study,a 300 mm×300 mm×300 mm size cement mortar cube test block is used,the equivalent explosive content is 3 g,the first,and the second and the third principal stress of the test block under confining pressure is 8.50 MPa,7.00 MPa and 5.75 MPa,respectively.The spatical morphology difference of blasting crack with and without confining pressure is compared and analyzed.It is found that the spatial morphology of the blasting crack under confining pressure is very different from that under a blasting free surface condition.Under the condition of surrounding blasting free surface,the test block was broken into fragments by blasting.The mass proportion within the range of the fragmentary size L<100 mm and 100 mm≤L<200 mm accounts for 30% and 70% of the total mass of the test block respectively,among which the mass of the large size 150 mm≤L<200 mm accounts for 55.32%.However,the quantity was small and they were all generated on the surface of the test block.Under confining pressure,a symmetrical macroscopic fracture surface which is on the hole sealing device is formed perpendicular to the direction of the second principal stress.Meanwhile,more cracks appear on other surfaces of the test block.After the test block is cut,microcracks appear on the hole wall,and obvious cracks appear on the hole wall in the pre-perforated direction.

关 键 词：爆炸致裂 围压 真三轴设备 裂纹空间形态 

分 类 号：TD235[矿业工程—矿井建设]