Entity

Time filter

Source Type

Longgang, China

Zhang B.,Shandong University | Zhang B.,Shandong University of Science and Technology | Li S.,Shandong University | Yang X.,Shandong Urban Construction Vocational College | And 6 more authors.
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2015

The mechanical properties of rock masses with intersecting multi-flaws under uniaxial compression were studied with specimens of rock-like material. Two kinds of intersecting multi-flaws were considered, one was comprised of the primary flaws and the secondary flaws, and the other one was composed of the multi-flaws with the same length. The specimens were tested under the uniaxial compression. The strength of specimen with two intersecting multi-flaws was higher than that of specimen with a single flaw. The strength of specimen with more than two intersecting multi-flaws composed of a primary flaw and secondary flaws was almost the same with that of specimen with a single flaw. Those specimens with more than 2 intersecting flaws with the same length as the primary flaw had the lower strengths than the specimen with a single flaw. The increasing of the number of the secondary flaws had little influence on the strengths of specimens with the intersecting multi-flaws composed of a primary flaw and secondary flaws. However, the increasing of the number of flaws had great influence on the strengths of specimens with intersecting multi-flaws composed of flaws with the same lengths. Most of the strain values corresponding to the peak strength of specimens with intersecting multi-flaws were lower than that of specimen with a single flaw. The initial stress of fracturing of the specimen with the intersecting multi-flaws composed of a primary flaw and secondary flaws were higher than that of specimen with a single flaw. Most of the initial stresses of fracturing of specimens with the intersecting multi-flaws composed of flaws with the same length to the main flaw were lower than that of specimen with a single flaw. The failure surfaces of the specimen with a single flaw under the uniaxial compression were shear cracks, but most of the failure surfaces of specimens with the intersecting multi-flaws were tension cracks. ©, 2015, Academia Sinica. All right reserved. Source


Wang Q.,Shandong University | Wang Q.,China University of Mining and Technology | Pan R.,Shandong University | Pan R.,Anhui University of Science and Technology | And 8 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2016

According to the field investigation and experiments on a typical gob side entry-material roadway of working face 4606 in Liangjia Coal Mine, the failure mechanism of surrounding rock under original supporting plan was analyzed. The complex structure of coal seam, the easy expansion and softening of surrounding rock, large destruction scope, serious arch deformation, and ineffective support were the main causes of roadway failure. Taken bolt-grouting support as a core measure, two supporting test schemes, namely U type shed+grouting bolt+grouting cable and grouting bolt+grouting cable, were proposed. The results show that the surrounding rock deformations are less than 37% compared with original supporting plan. U type shed does not play an obvious role in controlling surrounding rock, therefore, the grouting bolt + grouting cable can replace U-type shed. © 2016, Editorial Office of Journal of China Coal Society. All right reserved. Source


Wang Q.,Shandong University | Wang Q.,State Key Laboratory of Mining Disaster Prevention and Control | Wang Q.,Yankuang Group Company Ltd | Wang D.-C.,Shandong University | And 8 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2015

To overcome the problem of high stress roadway support in deep mine, a new support form-U-type confined concrete (UCC) arch centering was developed. In order to definite the mechanical properties and deformation failure mechanism of UCC arch centering, various experiments were carried out by using underground engineering confined concrete arch 1:1 mechanism test system and numerical computing method. The results show that under the pressure loading conditions, the yield load of UCC29 arch is 1 230 kN and the limit load of UCC29 arch is 1 310 kN, the differences between laboratory test and numerical simulation results are only 8.86% and 12.5% respectively. The arch deformation form is “vault rises, legs restrained and global variable thin”, the maximum deformation region is the central legs to sprung arch position. The deformation failure mechanism of arch is global variable instability caused by local strength yield. The application shows the surrounding rock control effect of UCC arch centering is good, and the UCC arch centering is a new effective support for deep mine high stress roadway. ©, 2015, China Coal Society. All right reserved. Source


Jiang B.,Shandong University | Li S.-C.,Shandong University | Wang Q.,Shandong University | Wang Q.,Anhui University of Science and Technology | And 9 more authors.
Meitan Xuebao/Journal of the China Coal Society | Year: 2015

According to the field investigation and experiments at No. 4606 transform cut of working face in Liangjia coal mine, which is a typical soft rock roadway, the failure mechanism of surrounding rock under primary plan was analyzed. The results demonstrated that the complex structure of coal seam, the easy expansion and softening of surrounding rock, large destruction scope, serious arch deformation, and unrealized supporting potential were the main causes of rock failure. Anchorage performance tests show that compared with the drawing force before grouting, grouting bolts increase 214% after 10 days, and high strength cables increase 89%. Took bolt-grouting support as the core measure, two supporting test schemes, namely U type shed + grouting bolt and grouting bolt + high strength cable were proposed. The results show that the surrounding rock deformations are less than 59% compared with primary plan's, differed by 6.6%. Therefore, the grouting bolt + high strength cable can be used to replace U type shed. © 2015, China Coal Society. All right reserved. Source

Discover hidden collaborations