1、翻译部分英文原文An experimental study of a yielding support for roadways constructed in deep broken soft rock under high stressLu Yinlong , Wang Lianguo, Zhang Bei State Key Laboratory of Geomechanics and Deep Underground Engineering, China University of Mining & Technology, Xuzhou 221008, ChinaAbstract:A r
2、ationally designed support for deep roadways excavated in broken soft rock under high stress was investigated. The deformation and failure characteristics and the mechanism ofyielding supportwas studied for anchor bolts and cables. The rail roadway of the 2-501 working face in the Liyazhuang Mine of
3、 the Huozhou coal area located in Shanxi province was used for field trials. The geological conditions used there were used during the design phase. The newhighly resistant, yieldingsupport system has a core of high strength, yielding bolts and anchor cables. The field tests show that this support s
4、ystem adapts well to the deformation and pressure in the deep broken soft rock. The support system effectively controls damage to the roadway and ensures the long term stability of the wall rock and safe production in the coal mine. This provides a remarkable economic and social benefit and has broa
5、d prospects for fur-ther application.Keywords:high stress,broken soft rock, roadways, Yielding support, Yielding anchor bolt1 IntroductionThe depth of coal mining increases year by year as the reduction and depletion of coal resources in shallower parts takes place. The complex geological conditions
6、 deep underground, high ground stresses and structural stresses for example, cause some rock around the roadways to break down and rapidly expand under the high stress. After failure the area of broken rock has increased and the dilatant deformation pressure after cracking becomes very strong. Roof
7、falling is accompanied by rib spalling and bottom heave on occasion. The roadways often require repeated maintenance and renovation for these reasons. Moreover, safety cannot be guaranteed and the costs of support are high leading to a decrease in mine efficiency 13. The stress environment, and the
8、deformation and failure characteristics, of such roadways allow them to be dened as high stress, deep broken soft rock roadways.The object during support of high stress deep soft rock roadways is to stabilize the cracked rock that has considerable residual strength and intrinsic stability 47. Inadeq
9、uate maintenance allows the roadway deformation to increase until, ultimately, there is a failure of the roadway. Therefore, a rational way to support deep broken soft rock roadways under high stress must be found.Studies have shown that support strength is the key factor for controlling the severe
10、deformation of the roadway wall rock 812. In principle, only when the support strength is greater than 0.3MPa can deformation be effectively controlled. Practice shows that, however, the range of stress that the support structure can withstand is rather narrow before and after failure. No matter wha
11、t kind of support is used the maximum stress that the support structure can bear is of the same order of magnitude. For example, the anchor bolt supports can provide from 0.05 to 0.2 MPa support. A single light steel frame can provide from 0.05 to 0.1 MPa of support while a heavy steel frame can pro
12、vide 0.2 MPa of support. There-fore, for these roadways it is difcult to control the severe deformation by relying on the support capacity of a single type of anchor bolt or other support.As a consequence of this it appears necessary for the roadway to have a self-support capacity. The interaction b
13、etween the wall rock and the support is such that the deformation of the wall rock is inversely proportional to the deformation in the support. Effectively stabilizing the deep broken soft rock roadway under high stress requires the support design to include intrinsic support from the rock wall, its
14、elf. The two important support parameters that can be adapted to supporting the stress and deformation are the carrying capacity and the reducible capacity. Making use of the self-support capacity of the roadway requires that the support system have both enough strength and enough yielding capacity.
15、 The support system then has the function of allowing some deformation that would otherwise be beyond its control. At the same time this yielding must be controlled in a way so the support system slowly releases the pressure in a given region while continuing to provide a supporting force. The yield
16、ing must not be free of restraining force. Thus, by allowing a certain amount of deformation in the wall that releases a part of the energy the pressure on the support system is reduced and larger deformation of the surrounding rock is effectively controlled. This partial release of energy can be called the unloading effect.In this paper a theoretical analysis and eld tests of the feasibility and technical issues related to a new high r
