外文翻譯--煤巷中相似模擬錨桿支護(hù)的構(gòu)造應(yīng)力場(存儲版)
【正文】 0， the load on the bolts changes little． The roof bolts are deformed mainly because of shear． The length of the extension of the lead wire is small， so that the change in resistance of the bolts is also small． Under the effect of tectonic stress， the roof and floor strata are likely to bee shear failure areas． There is a loose swell caused by dislocation， causing deformation in the surrounding rock． The function of the bolts is to constrain the strata from swelling along the axis and to prevent shear perpendicular to the axis． Therefore， the bolts must have properties of high strength， high stiffness and a high shear force， so that it can restrain deformation of the rock． Fig． 5 Changes in electrical signals in bolts This analysis shows that side bolts largely control the sides of the roadway in order to prevent deformation into the roadway space and that roof bolts mainly control shear failure of the roadway． When the rocks are destroyed， the bolts provide the binding force and increase the residual strength of the rocks． In the design of bolt support， we should select bolts with strong tensile ability and high elongation as side bolts， in order to release some deformation energy and which are adaptable to large deformations of the coalin side walls． Bolts with high antishear ability and high stiffness should be selected for roof bolts， to prevent separation， dislocation and shear failure of roof strata． 5 Conclusions From our similarity simulation of bolt support for a coal roadway in a tectonic stress field， we conclude the following． 1)With an increase in tectonic stress， the destruction of the roadway rock accelerates， there is dislocation between the strata in the roof and floor of the roadway and separation between strata gradually increases， 1eading to strata weakness because of shear and a loss of bending ability。Technology． This platform consists of three systems， a loading part， a frame and test devices． as shown in Fig． 1． The loading system consists of a hydraulic pump， a hydraulic control panel， a hydraulic pipeline and hydraulic pillows； the flame consists of baffles and the test system consists of a displacement sensor,a stress sensor,an electric circuit， a T$3890A programmable static resistance strain gauge and a puter． This experimental system can exert unequal forces in three directions on the model and precisely simulate the problem of plane strain． For the problem of simulating a roadway,a plane strain model is closer to actual conditions than a plane stress model． The main parameters and characteristics of this system are as follows： 1)The length， width and thickness of the mode flame are 1． 0， 1． 0 and 0． 2 m． 2)The hydraulic pillows are used to load the six sides of the model， where every hydraulic pillow covers one side； the maximum stress exerted on the model surface can reach 10 MPa． 3)The hydraulic system， controlled by high pressure， Can load the model for a long time under stable conditions． 4） By using difierent kinds of sensors connected to the puter,data of various observations can be monitored in realtime． Fig． 1 Experimental platform of true triaxial roadway simulation 3． 2 Parameters In order to reflect directly and suitably the destruction of the roadway and the functional mode of the bolts affected by tectonic stress， we used a geometric similarity constant for the model， lα ， of 20； the s
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鄂ICP備17016276號-1