【作者】 李冬；

【导师】 沈世伟；

【作者基本信息】 吉林大学 ， 地质工程， 2018， 硕士

【摘要】 随着国家对现代化建设的大力投入,地下工程、基建、交通等各个领域的工程建设蓬勃开展。在这些工程建设中,岩体爆破技术都有着广泛的应用。但由于岩体本身具有非均质性和各向异性,且岩体中含有的各种不同产状、不同尺寸的结构面,使得岩体爆破过程复杂多样,爆破效果难以把控,在增加施工成本的同时,也对工程施工及运营期间的人民生命财产构成严重威胁。弄清爆炸荷载在岩体破坏中的作用形式以及含节理裂隙岩体的破坏形式成为提高爆破质量,改善爆破效果的关键。本文对爆生气体驱动下裂纹的扩展特性进行理论分析,并为研究应力波与爆生气体共同作用下含裂纹岩体的动态破坏特性,分别进行单裂隙和多裂隙下的双孔爆破试验,主要得到以下成果:(1)根据爆破冲击相关理论,炸药起爆后,在爆炸应力波作用下,炮孔周围形成径向裂纹,随后爆生气体楔入裂纹,并在其内部膨胀流动。本文建立爆生气体驱动裂纹扩展计算模型,计算出爆生气体在裂纹内膨胀流动规律以及爆生气体驱动下裂纹扩展规律。(2)开展单、多裂隙缺陷双孔爆破试验,控制合理的装药不耦合系数,使裂纹扩展最大化。试验发现:(1)预制裂隙对炮孔主裂纹的形成扩展具有明显导向作用。当多条预制裂隙大角度展布在两炮孔间时,这种导向作用会有减弱现象。(2)预制裂隙在炮孔间的位置对炮孔主裂纹扩展速度有明显影响。(3)预制裂隙会在应力波及反射应力波作用下发生破坏,裂纹尖端延伸出衍生裂纹向炮孔方向扩展,同时预制裂隙的破坏过程具有明显的规律性。(4)炮孔主裂纹与预制裂隙及衍生裂纹在一定距离范围内,会相互影响,交错贯通,从而在两炮孔形成破碎带。(3)受预制裂隙影响,两炮孔间形成“锯齿形”的贯通面,偏离炮孔连线方向,预制裂隙角度越大,偏离幅度越大。更多还原

【Abstract】 Because of the significant investment in the modernization construction,many fields of construction are booming,such as underground engineering,infrastructure,transportation,and so on.And the rock blasting technology has been widely used in these fields of construction.But rock mass itself possesses in homogeneity and anisotropy,and it contains different types of structure planes with different attitudes and sizes,this makes the process of rock blasting more complicated and the controlling blasting effect more difficult.In order to improve the blasting quality,obtain satisfactory blasting effect and save construction cost,it is pivotal to understand the role of explosion load in rock mass destruction and the failure mode of jointed crack rock mass.This paper analysis the characteristics of cracks propagation drived by the detonation gas.And the dynamic damage characteristics of rock mass containing joints were obtained by double hole blasting experiments on rock mass containing single and multiple joints.There are some specific conclusions as following:(1)According to the theory of rock explosion,after explosive detonation some radial cracks are formed around the hole under the action of blasting stress wave,then the detonation gas inflates and flows into these radial cracks.This paper established calculation model of fracture propagation driven by gases of explosion and calculated the raw of detonation gas expansion flow within these cracks and cracks propagation driven by detonation gas.(2)By double hole blasting experiments on rock mass containing single and multiple joints with reasonable uncoupling loading coefficient that made cracks longest,this paper found following achievements.(1)The joint cracks had obvious guiding effect on the formation and expansion of the main cracks around the hole from.When multiple large dip join cracks were distributed between the two holes,the guiding effect would be reduced.(2)The position of the joint cracks between the two holes had obvious influence on the velocity of the main crack propagation.(3)Under the experimental condition of two-hole blasting,the prefabricated joint cracks ruptured by reflected and transmitted wave,and the two tips of prefabricated joint cracks extended the derivative cracks out,then derivative cracks extended to the hole.There were some significant regularities in the process of the prefabricated joint cracks propagation.(4)When the intersection of the main cracks,the prefabricated joint cracks and the derivative cracks were near,they would be interrelated by each other to form the fracture zone between the two holes.(3)Because of the prefabricated joint crack,there was a zigzag through plane between the two blast holes.And the through plane deviated from straight lines connecting the two blast holes.The larger angle of the prefabricated crack,the greater degree of deviation.更多还原