1、PDF外文：http:/ 汉字， 2045 单词， 10400 英文字符 出处： Wang J X, Lin M Y, Tian D X, et al. Deformation characteristics of surrounding rock of broken and soft rock roadwayJ. Mining Science and Technology (China), 2009, 19(2): 205-209. Deformation characteristics of surrounding rock of broken and soft rock ro
2、adway JX Wang, MY Lin, DX Tian, CL Zhao Abstract: A similar material model and a numerical simulation were constructed and are described herein. The deformation and failure of surrounding rock of broken and soft roadway are studied by using these models. The deformation of the roof and floor, the re
3、lative deformation of the two sides and the deformation of the deep surrounding rock are predicted using the model. Measurements in a working mine are compared to the results of the models. The results show that the surrounding rock shows clear rheological features under high stress conditions. Defo
4、rmation is unequally distributed across the whole section. The surrounding rock exhibited three deformation stages: displacement caused by stress concentration, rheological displacement after the digging effects had stabilized and displacement caused by supporting pressure of the roadway. Floor heav
5、e was serious, accounting for 65% of the total deformation of the roof and floor. Floor heave is the main reason for failure of the surrounding rock. The reasons for deformation of the surrounding rock are discussed based on the similar material and numerical simulations. Keywords: soft rock roadway
6、； broken surrounding rock； similarity simulation； numerical simulation； deformation characteristics. 1 Introduction As the depth of underground mining and railway tunnel construction increases failure problems in the soft rock get increasing attention from departments of scientific research an
7、d construction. In the 1970s, Salamon M D et al. proposed the energy supportingtheory. They thought that the supporting structure and surrounding rock of a roadway interact with each other and deformed together. The supporting structure absorbs part of the energy that the surrounding rock releases i
8、n the deformation stage. However, the total energy does not change. Yu X F et al. proposed that the failure of surrounding rock of roadway was the result of stresses exceeding the strength limits of the rock. Landslide changes the axis ratio of the roadway, which leads to stress redistribution, i.e.
9、 a reduction in high stress and an increase in low stress to reach a stable balance. The roadway would be steady when the stress is equally distributed: Its final shape is elliptic. Dong F T et al. proposed the theory of the broken rock zone around roadway. His basic viewpoint was that the broken ro
10、ck zone of a bare roadway is close to zero. Although elasto-plastic deformation of surrounding rock of the roadway occurs, the rock needs no supporting. Deformation increases with an increase in the broken rock zone. And the bigger the deformation is the more difficult support is. Therefore, the pur
11、pose of support is to prevent harmful deforma tion in the broken rock zone around roadway. The distribution of the plastic zone and an asymmetrical control mechanism of the surrounding roadway rock using weak structures were discussed in Reference . Meanwhile, the stability of surrounding rocks of r
12、oadways was studied from various points of view. Owing to the lack of research related to soft rock engineering or large deformations in soft rock, most soft rock roadways are currently maintained just after being dug. They are difficult to support, which is a disadvantage for safe production in the
13、 mine. This seriously influences the economic benefits of the enterprise. Therefore, the deformation and support of soft rock roadway is one of the key problems of coal mining. Developing safe production requires better information. The deformation of a broken soft rock roadway is simulated by a sim
14、ilar-material experiment and by a numerical model based on geological conditions and supporting parameters of a refitroadway. The results are described in this paper. The deformation and failure characteristics of a broken soft rock roadway were analyzed based on the measured results. 2 Analys
15、is of engineering conditions 2.1 Geological conditions The roadway studied is at a level of 600 m. The ground elevation is +160 m so the total depth of the roadway is 760 m. The roof of the roadway is 26 m below Coal 2 and the floor of the roadway is 14 m above Coal 3. The surrounding rocks of
16、 the roadway are mostly grey and black sandy mudstone. The mine-field structure is complex. The ground stress is high: the maximum principal stress is 2530 MPa at cleavage fractures are an azimuth of 270o275o. The well developed in the surrounding rock and there is serious broken deformation. Normal
17、 work was affected by large rapid deformations in many of the roadways. The effect is particularly obvious when the roadway is being dug and coal is being mined. Shrinkage of the roadway cross section is generally 30% and can sometimes reach 60%, which seriously affects safety during production. A g
18、eologic histogram of the roadway is shown in Fig. 1. The section of the original design is a straight wall with an arch at the top. The original cross section as designed was 4.53.85 m 2. A combined support of U36 steel together with bolting and shotcrete with wire meshwas applied. The row distance
19、of the steel was 600 mm； the length of the bolts was 2.0 m； the diameter of the bolts was 20 mm. A bolt was anchored with two resin cartridges. The row distance of the bolts was also 600 mm. The thickness of the shotcrete with C20 was 150 mm. The original cross-sectional area of the roadway was 15.1 m 2. . Fig. 1 Geologic histogram of the roadway 2.2 On-the-spot observation of the deformation of the surrounding rock Three stations are set in the north second cart way for observing convergent
