外文翻译--煤巷中相似模拟锚杆支护的构造应力场(编辑修改稿)

外文翻译--煤巷中相似模拟锚杆支护的构造应力场(编辑修改稿)内容摘要：

stress of the bolts in roof and side walls． The similarity experiment consisted of four schemes： vertical stress exerted on a roadway was 0． 50 MPa in each scheme． we allowed horizontal tectonic stress to increase from 0． 25， 0． 50． 1． 00 to 1． 50 MPa and the side pressure coefficient A from 0． 5， 1． 0， 2． Oto 3． 0． 3 Experimental 3． 1 System In order to approximate strata behavior of bolt support in a coal roadway,we used a true triaxial roadway simulation experimental platform developed by China University of Miningamp。 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 size， pι ， of the roadway designed was 4 m3 m． The material used to simulate rock consisted of sand， CaC03， cement and gypsum with a water content of 1／ 1 0 and a bulk density of about 1． 50 3/cmg ． The bulk density of the original rock， pγ ， was 2． 50 3/cmg ， with a similarity constant of bulk density, γα ， of 1． 67． The intensity similarity constant， tσα ， was tσα = lα γα =33． 4． The model parameters and material ponent ratios are shown in Table l and the experimental model in Fig． 2． Fig． 2 Experimental simulation model Table 1 Model parameters and material ponent ratios 3． 3 Data monitoring Given the objective of the experiment， we needed to monitor the surface displacement of the roadway and forces acting on the bolt． The layout of the monitoring equipment is shown in Fig． 3． A displacement meter was placed on the surface of the roadway,with a bolt buried inside the rock in advance． Using a φ 1． 8 mm lead wire to simulate a bolt,a copper wire was attached to both ends of the lead wire ， leading to the outside of the model and connected to the TS3890A programmable static resistance strain gauge． Measuring the electric signals of the lcad wire reflects the condition of the force to the lead： the larger the pulling force exerted on the lead wire， the thinner it bees and the larger the resistance，。