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英文原文Surrounding rock deformation regularity of roadway under extremely complicated geological conditions in deep mine and its controlAbstract：By combining the practices of deep mine mining in Changguang Mine field and using the Universal Distinct Element Code3.0（UDEC3.0） numerical computing method, the distribution characteristics of deformation field and stress field as well as the surrounding rock deformation regularity of soft rock roadway are analyzed under extremely complicated geological conditions, a technical principle of bolting to control the surrounding rock of roadway is put forward. And also using a dynamic control for surrounding rocks designing method, the supporting parameters and implement plan are rationally determined. The experimental tests have obtained a good controlling result of surrounding rock.Keywords：deep mine, extremely complicated geological condition, surrounding rock deformation, dynamic controlling designIntroductionThe geological conditions of coal seams in China are complicated and varied, the mines with soft rock can be found all over the main coal production provinces and regions, and the coal mines with soft rock exist in the approximate half of coal fields. With increasing the mining depth of mine, the soft rock roadways of the production mines have such problems as great deformation, great rock pressure and difficult support etc. Changguang Coal field is a typical soft rock coal field and its geological condition is extremely complicated. With increase of mining depth of mine, U-steel support has been difficult to control the surrounding rock of roadway effectively and the problem of roadway support is more serious.In this paper, the surrounding rock deformation characteristics of roadway under the extremely complicated geological conditions is analyzed based on the bolting pattern, and the thought of supporting design and dynamic control of surrounding rocks is used to carry out determination of support parameters and design of the implement plan. It is of a great significance for the surrounding rock control of soft rock roadway.1 Maintenance characteristics of main roadway and geological conditionsIn Changguang Coal field, coal seam C of Permian vauclusian spring group is mining now, the roof of coal seam consists of black arenaceous mud stone with black mud stone and its floor consists of bauxitic mud stone. The percentage of rock expansion is 20.2%31.8% and the compressive strength lies mostly between 937 MPa. And strata are mainly thin bedded strata, the grain is loose, the joint is well developed, the cohesion is weak and it is easy to beweathered and expanded when being caught in water.The rock roadway of No.7 Mine in -850 level is located in western side of synclinal axis of Niutou Mountain, the buried depth is -920m. Within the excavated range of 530m, there are 15 newly exposed small and great fracture structures, except the fracture structure F702 which has been controlled, among them there are 8 normal faults and 7 up throw faults, they are all compressed shearing oblique faults. The fault with drop height of 20m is at a distance from the experimental section of roadway by 30 m, and under influence of the fault structure, the original unstable roof and floor rocks are seriously damaged, main phenomena are that strata angle changes greatly, the phenomenon of strata inversion occurs now and then, the cross strata of roadway is seriously and the rock bedding is extremely crushed. According to lithological analysis, the lithological alternative change is frequently, and under a action of two group of stresses, the lithological strike is positive “S” shape.In view of the basic habitat of drift located in -850m level, the drift has obvious features as follows:The roadway belongs to a typical deep mine roadway, additionally, the surrounding rock stand-by condition of roadway is extremely complicated, the rock pressure of roadway is obviously increased, and on the engineering view, the roadway belongs to the typical difficult supporting roadway.The roadway is greatly influenced by the fault structure and the stand-by condition of stratum where the roadway is excavated changes greatly, thus, the maintenance difficult of roadway may be increased further.The strata angle changes from 15to 80, so that the deformation and pressure of roadway possesses an obvious directionality.The surrounding rock of roadway belongs to extremely unstable complex stratum, the stratum consists mainly of sandstone, mudstone, shale and its interbed, and the thickness of each slice is small, the bedding is extremely developed and the lithological change is quicker, it is difficult to get hold of real lithology of roadway surrounding rock.2 Surrounding rock deformation regularity of roadway under extremely complicated geological conditions2.1Establishment numerical computing modelThe numerical calculation is carried out using UDEC3.0 large size numerical computing software. The simulation range is 30m30m （lengthheight）, and the computing model uses the boundary conditions of stress, i.e. the well distributed vertical compressive stress is exerted on the upper surface of the model, the horizontal compressive stress with change of depth is exerted on both sides of the model, and on the bottom boundary of the model, the vertical displacement is fixed and on the boundary of both right and left sides the horizontal displacement is also fixed. When the strata angles are 25, 45and 75, the numerical calculation mainly analyses the surrounding rocks deformation characteristics of rock roadway under the complicated geological conditions and the distribution features of stress field and displacement field. The numerical computing model is shown in Fig.1 when the strata angle is 45.Fig.1Numerical computing model2.2Numerical computing results and analysis（1） Strata angle up to 45. The roof convergence of roadway reaches up to 419 mm, the floor heave is 1108 mm,and the convergence on the left roadway side is 617 mm and 548mm on the right roadway side. The range of plastic zone in left roadway side and floor near the left side is greater. The surrounding rocks horizontal displacement of left roadway side is greater than that of right roadway side. The vertical displacement of surrounding rocks mainly is concentrated on the roof rock of roadway near the right side and on the floor rock of roadway near the left side; the latter indicated that the floor heave amount is greater. Fig.2 shows the distribution of vertical displacement field and displacement vector. The concentration zone of vertical stress exists in the floor rock of roadway near the left side and in the roof rock of roadway near the right side. The horizontal stress is concentrated on the floor near the left side and below both sides of roadway corresponding to the distribution of plastic zone.（2） Strata angle up to 25. The surrounding rock deformation damages of roadway display mainly a great amount of floor heave and a great convergence of both sides, specially, the deformation of left side and floor is obvious. And the horizontal stress and the vertical stress of roadway surrounding rock are concentrated on both sides and floor of roadway, the degree and range of the stress concentration are greater, and this is the main stress condition for resulting in the final damage of roadway. At the top of the roadway, the degree and range of the stress concentration are relatively smaller.Fig.2Distribution of vertical displacement field and displacement vector（a） Vertical displacement field; （b） Displacement vector（3） Strata angle up to 75. Under habitat of the stratum, the rock deformation around roadway shows mainly a great amount of floor heave of roadway, a great convergence of top surrounding rock and lower part of both sides. Owing to the serious surrounding rock deformation damage of roadway, the surrounding rock self stability of roadway is extremely poor.And the horizontal stress and surrounding rock vertical stress of roadway are completely concentrated on the top of both sides of roadway, the concentrated degree is also greater and the roadway bottom is depressed due to the serious damage.From above computing results, it can be seen that the deformation damage of roadway mainly shows a great amount of floor heave and a great displacement of both sides, but the floor heave is asymmetric. In the floor of roadway nearthe left side and roof near the right side as well as both sides near the floor, there exist the high stress concentrated zones. And the stress concentration degree and degree of the roadway deformation damage are influenced greatly by the strata angle.With increase of the strata angle, the surrounding rock horizontal displacement of roadway should be increased and the floor heave decreased to some extent, but the variable extent is 8501108 mm.3Supporting pattern of roadway surrounding rock and determination of surrounding rock dynamic control parameters3.1Controlling principle and supporting pattern of roadwaySince long time, U-steel support has been used all along in Changguang Coal Mine field. The application practice indicated this supporting pattern couldnt solve the supporting problem of main roadway in -850m level under the complicated geological conditions. A strengthening theory of rock strength put forward by Professor Hou Chaojiong from China University of Mining and Technology has laid a theoretical basis for effective controlling the soft rock roadway under the complicated geological conditions. This theory thought the essence of bolting action is a rock bolting interaction and a common bearing structure of surrounding rock with bolting is formed, thus, the mechanical parameters of bolted rocks can be improved, the strength of the bolted rocks should be increased, specially, the strength after peak value and the residual strength are strengthened, and the self bearing capacityof surrounding rock is brought into full play, so that the roadway surrounding rock can be changed from in stabilityto stability. Therefore, bolting is an effective supporting pattern for controlling the roadway surrounding rock under the complicated geological condition. According to the deformation characteristics and damage regularity of roadway surrounding rock, the controlling principles of roadway support are as follows:A top rocks control of roadway is strengthened to form a mutual limited structure of top surrounding rocks, and the incompatible deformation of top surrounding rocks and the delaminating fall of lower strata can be prevented after roadway excavation.Both sides of roadway should be reinforced to prevent the obvious increase of floor heave resulted from the large scale damage of both sides.Rock bolt and anchorage pattern should be chosen rationally, and the high-strength metal bolt and the anchorage pattern of overall length or extension are applied to adapt the characteristics of high ground pressure, great deformation and crushing of surrounding rocks.A complete set of necessary safety monitoring technique should be formed, including monitoring of bolt conditions, monitoring of surrounding rock deformation in deep roadway and evaluation of the supporting results.3.2Dynamic control supporting design of surrounding rock（1） Determination of supporting parameters. By using UDEC3.0 numerical computing software, the influences of bolt length, bolt rowspan, bolt distance and bolt arrangement on the control result of roadway have been analyzed. The computing results are: Bolt length are 1.6, 2.0, 2.4 m; Bolt row span are 0.6, 0.8, 1.0m; Bolt arrangement （left side, top, right side） are 232, 242, 343. From the computing results, it can be seen that the controlling result of roadway surrounding rock is obviously improved with extension of bolt length, but, after the bolt length reaches up to a certain value, the effect of increase of bolt length on surroundingrock control is relatively smaller, for example, if the bolt length is 2.0 m or 2.4 m, its control result of surrounding rock is obviously better than the control result of bolt length of 1.6m, and by using 2.0 m and 2.4 m bolts, the control results of rock deformation are similar. The smaller the bolt row span is, the better the result for controlling the surrounding rock is, but the smaller bolt row span may result in a certain difficult for bolt construction. Therefore, in the process of main roadway support in -850m level, the high performance twist steel bolt with 2.0 m length has been determined, the bolt row span is 08 m and the bolt arrangement is“242” pattern of left side/top/right side.（2） Support design of surrounding rock dynamic control. Because the stand-by condition of strata is extremely unstable and the change of strata angle is also greater, a dynamic control method for controlling the surrounding rock of roadway is used, that is, in the changing range of different strata angles, the different bolting patterns are applied to adapt the pressure feature and the deformation regularity of surrounding rock. If the strata angle is 1535, it can be completed according to the support plan of dip angle of 25. If the strata angle is 3555, the support plan according to the dip angle of 45can be used, and if the strata angle is 5580, the support plan according to the dip angle of 75can be implemented. Because the critical positions of roadway support are located in the roadway floor near the right side, roof near the left side and both sides near the floor, the supporting control of these ranges is strengthened by bolting and it maintained that the bolt situated in the right apex corner of roadway is perpendicular to the bedding plane of strata. The bolt angle in the left bottom corner of roadway is 15, other bolt angles should be properly adjusted according to the strata angle. Fig.3 shows design of roadway support if the strata angle is 45.Fig.3Bolting design of roadway by 45dip angle4Measured analysis of roadway surrounding rock control results（1） Rock deformation of roadway surface. The total roof to floor convergence and the convergence of both sides are on the average 86.5 mm and 67.5 mm respectively. Within 50 days after the roadway excavation, the average roof to floor convergence rate and the average convergence rate of both sides are 1.65 mm/d and 1.3 mm/d respectively, thus,the bolting has effectively controlled the rock deformation of roadway. In the section supported by U- steel, the rock deformation of roadway is greater and the deformation is yet not convergent. And the total roof to floor convergences and the total convergences of both sides are on the average 188 mm and 140 mm respectively, the average convergences of roof to floor and both sides are 3.35 mm/d and 2.4 mm/d separately.（2） Deep displacement of roadway surrounding rock. The actual measurement indicated that there exists 9.6mm displacement at the measured points of both sides apart from the hole top by 0.8m, the displacements at other deep measured points （including the top displacement） are all smaller than 1mm, and the measured results show that the deformation of surrounding rock has tended to a stability.（3） Monitoring of bolt bearing. Observations indicated that within 20 days after supporting roadway by using bolting the bolt bearing increases rapidly, compared with the initial pressure of bolt, the bolt bearing increases on the average by 40%, but within 2035 days the bolt bearing increases slowly, average increasing by 11.3%, and after 35 days, the bolt bearing tends to a stable period. The bolt and the support body of surrounding rock possess all fine bearing capacity and self stable capacity.5Conclusions（1） The surrounding rock deformations mainly show a great amount of floor heave and the convergence of both sides,and affected by the strata angle, the floor heave is asymmetric in shape. The vertical stress of surrounding rock is mainly concentrated on the roof and floor of roadway; the horizontal stress is mainly concentrated on the bottom of both sides of roadway.（2） Taking the strengthening theory of rock strength by using bolting as a basis, bolting is used to strengthen the top surrounding rock of roadway and reinforce both sides, thus, the high resistance yielding support is realized, rational choice of bolt and anchorage pattern and implement of the safety monitoring are the effective technical ways of surrounding rock control of roadway.（3） According to the change of the strata angle, a support designing method of surrounding rock dynamic control is used to determine the supporting parameters rationally, it is a linchpin to ensure the effective control of surrounding rock of soft rock roadway under the complicated geological conditions.（4） Observations indicated that the deformation of roadway is very small, the convergence rates of roof to floor and both sides are smaller than 1.65mm/d and 1.3mm/d respectively. The deep rock mass of roadway possesses the fine complete stability, the bolt bearing is stable and of fine controlling results of surrounding rock.中文译文复杂地质条件下深部矿井的巷道变形规律及其控制摘要：结合矿山开采的实践，在长广矿区深部矿井中使用UDEC3.0数值模拟计算的方法，分析了软岩在极其复杂的地质条件下形变场的和应力场的分布特点以及巷道围岩变形规律，利用锚喷控制巷道变形的技术原理，利用动态设计控制围岩的方法，对支护参数及实施方案是否合理进行实验，并且实验测试结果取得了较好的围岩控制效果。关键词：深井；复杂地质条件；围岩变形；动态控制设计引言：我国的煤层的地质条件是复杂多变的，软岩矿井广泛分布于主要的煤炭生产省份和地区，因此近一半的矿井面临软岩支护的问题。随着矿井开采深度的增加，生产矿井的软岩巷道大变形，大地压和难支护的问题变得日益严重。长广煤田是一个典型的地质条件复杂的软岩煤田。随开采深度的不断增加，U型钢支架已经难以有效的控制巷道围岩变形，巷道支护的问题也变得更加严峻。在本文中，利用锚杆支护原理分析了在极其复杂地质条件下巷道围岩变形的特点及支护设计，用围岩动态控制的思想来进行支护设计参数的确定及方案的实施。它对软岩巷道的围岩控制具有重要的意义。1 大巷的维护特点和地质条件在长广煤田，正在开采的二叠纪龙潭组号煤层，煤层顶底板分别由的黑色泥质石砂岩和铝土质泥岩组成。岩石膨胀的系数是20.231.8，抗压强度主要在937之间。地层主要是薄层状地层，层理松散，节理发育，当遇水时由于内聚力弱，很容易发生风化和倾斜。7号矿-850m水平的岩巷位于牛头山向斜轴西侧，埋藏深度为-920m。在开掘岩巷的530m范围之中，除了已被控制的断裂构造F702，有15个新发现的大小断裂构造，其中有8个正断层和7逆断层，他们都是在压缩剪切下形成的斜断层。试验段巷道前30m的距离有20m高差的断层，在断裂构造的影响下，原有的不稳定的顶板和底板的岩石严重破坏，主要现象是各地层的角度变化很大，地层反转的现象时有发生，跨地层的巷道严重破坏、岩层变得极为破碎。根据岩性分析，岩性替代变化频繁，在两组应力的作用下，岩性失效呈“S”形。位于-850m水平的巷道变形具有如下明显的特点：巷道属于典型的深井巷道，此外，巷道的围岩条件非常复杂，围岩压力明显增加，从工程角度看，传统的支护方式难以维护巷道。断裂构造和倾角变化很大的地层极大地影响了正在掘进的巷道的维护，因此，巷道维护困难会进一步增加。地层角度的变化，从，巷道的变形和压力具有明显的方向性。巷道围岩属于极不稳定的复杂地层，地层主要由砂岩，泥岩，页岩及其夹层为主，每个地层的厚度小，层理极其发育，岩性变化快，很难找到巷道围岩真正的岩性。2在极其复杂的地质条件下的巷道围岩变形规律2.1建立数值计算模型使用UDEC3.0大尺寸的数值计算软件进行数值计算。模拟范围为30m30m（长度高度），计算模型采用压力边界条件，即模型的表面上水平压应力随着深度增加而变化，均匀分布的垂直压应力加在模型两面，垂直位移固定在模型的底部边界，左，右两侧的边界上的水平位移也被固定。数值计算主要分析了当地层的倾角是25，45和75，在复杂的地质条件下应力场和位移场的分布特征及岩巷围岩变形特点。地层倾角为45时的数值计算模型如图1所示。图1 数值计算模型2.2数值计算结果和分析（1）地层角度45。巷道顶板离层达419mm，底板鼓起1108mm，左右两侧巷道的片帮距离分别是617mm和548mm。巷道左侧底板附近的塑性区的范围也更大，巷道左侧围岩的水平位移大于巷道右侧。垂直位移主要集中在右侧巷道靠近顶板岩石和巷道左侧附近底板岩石附近，后者底板起伏较大。图2显示了垂直位移场和位移矢量的分布。巷道的左侧底板附近和右侧顶板附近垂直应力集中区存在。水平应力集中分布在巷道左侧和巷道下方两侧附近对应的塑性区。（2）地层角度25。围岩巷道变形损坏主要是巷道大量的底板鼓起和两侧的挤压，特别是非常明显的左侧和底板变形。巷道两侧的水平应力和底板的垂直应力出现集中现象，并且应力集中的程度和范围都较大，这是最终导致巷道损害的主应力条件。巷道的顶板，应力集中的程度和范围都相对较小。图2 垂直位移场和位移向量图的分布 （a）垂直位移场；（b）位移场（3）地层角度75。根据地层的特征，巷道围岩变形主要表现在大量巷道底鼓，顶部的围岩下沉和巷道两侧下部的变形。道围岩自身稳定性极差造成严重的巷道围岩变形由于巷。水平应力和垂直应力完全集中在巷道两侧的顶部，并且集中程度也更大，巷道底板受压严重，因此严重损坏。从上述计算结果，可以看出，巷道变形破坏主要表现在大量的底鼓和两侧的挤压，但是底鼓是不对称的。巷道左侧和右侧的顶底板附近存在高应力集中区。地层的角度的增加大大影响了应力集中程度和巷道变形破坏的程度。增加地层倾角，导致巷道围岩水平位移增加，但底鼓在某种程度下降，其变化范围为8501108mm。3巷道支护模式与支护参数的确定3.1巷道支护模式及原理很久以来，U型钢支架已广泛用于长广矿区。应用实践表明，这种支护模式不可能解决复杂地质条件下的-850m水平大巷的支护问题。中国矿业大学的侯朝炯教授提出的岩石强度理论技术，为复杂地质条件下有效控制软岩巷道变形奠定了理论基础。这种理论认为，锚杆支护的本质是利用锚杆和围岩的相互作用，因此，改变锚杆的岩石力学参数，通过增加锚杆的抗拉强度，峰值强度和残余强度，充分发挥围岩的自我承载能力，可以改变巷道围岩稳定稳定。因此，在复杂地质条件下，锚杆支护对围岩控制是很有效的。根据巷道围岩的变形特征和破坏规律，巷道支护的控制原则如下：岩石巷道顶部加固可控制顶部围岩变形，防止巷道掘进后地层和顶部围岩分层落下。巷道两侧应加强支护，以防止底鼓，巷道两侧变形严重。锚杆和锚固模式应合理选择，适用于高强度的金属螺栓，锚固的总长度或延长模锚固长度以适应大地压，大变形和围岩破碎的特点。应形成一套完整的必要的安全监测技术，包括监测深部巷道的锚固条件，支护结果及围岩变形。3.2巷道支护参数的确定（1）支护参数的测定。使用UDEC3.0数值计算软件对巷道的锚杆长度，锚杆间排距，锚杆距离和锚杆排列变化的控制效果影响进行了分析。变量分别是：螺栓长度为1.6m，2.0m，2.4m；间距为0.6m，0.8m，1.0m；螺栓排列（左侧，顶部，右侧）为232，242，343。从计算结果，可以看出，延长锚
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