CN112115599A - Method for calculating hole spacing of weakened top plate of intensive drilling - Google Patents
Method for calculating hole spacing of weakened top plate of intensive drilling Download PDFInfo
- Publication number
- CN112115599A CN112115599A CN202010945806.3A CN202010945806A CN112115599A CN 112115599 A CN112115599 A CN 112115599A CN 202010945806 A CN202010945806 A CN 202010945806A CN 112115599 A CN112115599 A CN 112115599A
- Authority
- CN
- China
- Prior art keywords
- borehole
- rock mass
- mass around
- mpa
- stress
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005553 drilling Methods 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims abstract description 16
- 239000011435 rock Substances 0.000 claims abstract description 151
- 238000004364 calculation method Methods 0.000 claims abstract description 14
- 238000011065 in-situ storage Methods 0.000 claims abstract description 13
- 230000003313 weakening effect Effects 0.000 claims abstract description 11
- 230000000694 effects Effects 0.000 abstract description 5
- 238000010276 construction Methods 0.000 abstract description 3
- 230000003321 amplification Effects 0.000 abstract description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 2
- 238000013467 fragmentation Methods 0.000 abstract 1
- 238000006062 fragmentation reaction Methods 0.000 abstract 1
- 238000005520 cutting process Methods 0.000 description 8
- 238000005065 mining Methods 0.000 description 8
- 239000003245 coal Substances 0.000 description 6
- 238000005422 blasting Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000009412 basement excavation Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 244000144985 peep Species 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000005381 potential energy Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Earth Drilling (AREA)
Abstract
本发明公开了一种密集钻孔弱化顶板孔间距计算方法,首先根据钻孔周围岩体塑性区的边界推导得到单个钻孔周围塑性区发育半径的理论计算公式;在塑性区发育计算公式中考虑到实际工程对塑性区发育的影响,得到钻孔周围岩体原位岩石力学性能;同时对钻孔周围的围岩破碎程度进行分级以确定放大系数,进而计算得到密集钻孔塑性区发育半径;最后可以确定密集钻孔弱化顶板孔间距。合理的密集钻孔孔间距可以使得钻孔的卸压区相互叠加、互相连通,从而形成人工岩体结构弱化带。本发明在保证了弱化顶板效果的同时,可有效的控制密集钻孔的孔间距大小,极大的减轻了施工作业工作量,进一步提高了矿井安全系数及生产效率。The invention discloses a method for calculating the spacing between densely drilled and weakened roofs. First, the theoretical calculation formula of the development radius of the plastic zone around a single drill hole is derived according to the boundary of the plastic zone of the rock mass around the drill hole; the calculation formula for the development of the plastic zone is considered According to the influence of actual engineering on the development of plastic zone, the in-situ rock mechanical properties of the rock mass around the borehole are obtained; at the same time, the degree of fragmentation of the surrounding rock around the borehole is classified to determine the amplification factor, and then the development radius of the dense borehole plastic zone is calculated; Finally, it is possible to determine the spacing between dense drilling and weakening the roof holes. Reasonable dense drilling hole spacing can make the pressure relief areas of the drilling holes overlap and connect with each other, thereby forming a weakened zone of artificial rock mass structure. While ensuring the effect of weakening the roof, the invention can effectively control the hole spacing of the dense drilling, greatly reduce the construction workload, and further improve the mine safety factor and production efficiency.
Description
技术领域technical field
本发明属于矿山顶板岩层控制技术领域,尤其涉及一种密集钻孔弱化顶板孔间距计算方法。The invention belongs to the technical field of mine roof rock formation control, and in particular relates to a method for calculating the spacing between densely drilled and weakened roof holes.
背景技术Background technique
弱化顶板通过改变顶板岩体的物理力学性质,减小顶板悬露面积,防止或减弱大面积顶板来压,以达到工作面安全、高效生产,是矿山综采的重要手段。The weakened roof is an important means of fully mechanized mining by changing the physical and mechanical properties of the roof rock mass, reducing the overhang area of the roof, preventing or weakening the pressure of a large area of the roof, so as to achieve safe and efficient production of the working face.
目前弱化顶板的常用方法主要有聚能爆破和水力压裂。但聚能爆破难以保证爆破孔孔间切缝率和爆破裂缝方向,存在爆破可控性低、对巷道围岩扰动影响严重等问题,且不适用于高瓦斯矿井。水力压裂虽然对巷道围岩扰动较小,适用性强,但是裂缝角度、裂缝高度、裂缝贯穿率有限,现场操作复杂,学习成本较高。针对以上问题有学者提出密集钻孔弱化顶板切顶卸压技术能够有效弥补上述方法的部分缺陷,能够有效解决煤矿深部开采沿空留巷过程中小煤柱开采时冲击地压过大的问题;也能够针对采空区坚硬顶板无法及时垮落、顶板内弹性势能大量积聚的情况,及时切顶卸压。但目前该方法对密集钻孔施工时孔间距的具体参数并未有科学计算方法。钻孔间距作为该技术的关键参数,若选取的孔间距太大,则不能满足顶板弱化的要求,无法达到卸压的效果;若选取的孔间距太小,虽然可以达到顶板弱化卸压效果,但劳动成本会大大增加。At present, the commonly used methods for weakening the roof mainly include shaped blasting and hydraulic fracturing. However, it is difficult for shaped blasting to ensure the cutting rate between blasting holes and the direction of blasting cracks. There are problems such as low blasting controllability and serious disturbance to the surrounding rock of the roadway, and it is not suitable for high gas mines. Although hydraulic fracturing has little disturbance to the surrounding rock of the roadway and has strong applicability, the fracture angle, fracture height and fracture penetration rate are limited, the field operation is complicated, and the learning cost is high. In response to the above problems, some scholars have proposed that the intensive drilling weakened roof cutting and pressure relief technology can effectively make up for some of the defects of the above methods, and can effectively solve the problem of excessive ground pressure during small coal pillar mining in the process of gob-side entry retention in deep coal mining. In view of the situation that the hard roof in the goaf cannot collapse in time and the elastic potential energy in the roof accumulates a lot, the roof can be cut in time to relieve pressure. However, at present, there is no scientific calculation method for the specific parameters of the hole spacing during intensive drilling construction. The drilling spacing is a key parameter of this technology. If the selected hole spacing is too large, it cannot meet the requirements of roof weakening and cannot achieve the effect of pressure relief; if the selected hole spacing is too small, although the roof weakening pressure relief effect can be achieved, But the labor cost will greatly increase.
发明内容SUMMARY OF THE INVENTION
发明目的:针对以上问题,本发明提出一种密集钻孔弱化顶板孔间距计算方法,可针对不同围岩条件进行钻孔施工间距计算,满足实际工程需要。Purpose of the invention: In view of the above problems, the present invention proposes a method for calculating the spacing between holes in a weakened roof with dense drilling, which can calculate the spacing between drilling holes according to different surrounding rock conditions and meet actual engineering needs.
技术方案:为实现本发明的目的,本发明所采用的技术方案是:一种密集钻孔弱化顶板孔距计算方法,包括如下步骤:Technical scheme: In order to achieve the purpose of the present invention, the technical scheme adopted in the present invention is: a method for calculating the distance between densely drilled and weakened roof plates, comprising the following steps:
S1,根据钻孔围岩受力情况,设定整个钻孔径向的受力作用一致,参考图6,以钻孔中心为圆心,建立二维极坐标系;S1, according to the force of the surrounding rock of the borehole, set the radial force of the entire borehole to be consistent. Referring to Figure 6, the center of the borehole is taken as the center of the circle to establish a two-dimensional polar coordinate system;
S2,根据弹性力学,极坐标下钻孔周围岩体的应力分量的公式为:S2, according to elastic mechanics, the formula for the stress component of the rock mass around the borehole in polar coordinates is:
式中,ρ为钻孔周围岩体任意一点的极坐标值;a为钻孔半径,mm;P为钻孔所在位置的水平地应力,MPa;σρ为钻孔周围岩体任意一点处的径向应力,MPa;σθ为钻孔周围岩体任意一点处的环向应力,MPa;τρ为钻孔周围岩体任意一点处的径向剪应力,MPa;τθ为钻孔周围岩体任意一点处的环向剪应力,MPa;In the formula, ρ is the polar coordinate value of any point of the rock mass around the borehole; a is the radius of the borehole, mm; P is the horizontal in-situ stress at the location of the borehole, MPa; σ ρ is the value of any point of the rock mass around the borehole Radial stress, MPa; σ θ is the hoop stress at any point of the rock mass around the borehole, MPa; τ ρ is the radial shear stress at any point of the rock mass around the borehole, MPa; τ θ is the rock around the borehole hoop shear stress at any point of the body, MPa;
S3,根据平衡条件和莫尔强度条件,基于步骤S2所述参数σρ、σθ和τρ,得到钻孔周围岩体中任意一点所在平面状态的极值应力公式为:S3, according to the equilibrium condition and Moiré strength condition, and based on the parameters σ ρ , σ θ and τ ρ described in step S2, the extreme value stress formula of the plane state where any point in the rock mass around the borehole is obtained is:
式中,σ1为钻孔周围岩体任意一点处平面内的最大主应力,MPa;σ2为钻孔周围岩体任意一点处平面内的最小主应力,MPa;σρ为钻孔周围岩体任意一点处的径向应力,MPa;σθ为钻孔周围岩体任意一点处的环向应力,MPa;τρ为钻孔周围岩体任意一点处的径向剪应力,MPa;In the formula, σ 1 is the maximum principal stress in the plane at any point of the rock mass around the borehole, MPa; σ 2 is the minimum principal stress in the plane at any point of the rock mass around the borehole, MPa; σ ρ is the rock around the borehole. radial stress at any point of the body, MPa; σ θ is the hoop stress at any point of the rock mass around the borehole, MPa; τ ρ is the radial shear stress at any point of the rock mass around the borehole, MPa;
进一步地,列出钻孔周围岩体在该平面上所受剪应力值τn和钻孔周围岩体在该平面上所受正应力σn的常用求解公式为:Further, the commonly used solution formula for listing the shear stress value τ n of the rock mass around the borehole on the plane and the normal stress σ n of the rock mass around the borehole on the plane is:
式中,τn为钻孔周围岩体在该平面上所受剪应力值,MPa;σn为钻孔周围岩体在该平面上所受正应力,MPa;σ1为钻孔周围岩体任意一点处平面内的最大主应力,MPa;σ2为钻孔周围岩体任意一点处平面内的最小主应力,MPa;In the formula, τ n is the shear stress value of the rock mass around the borehole on the plane, MPa; σ n is the normal stress of the rock mass around the borehole on the plane, MPa; σ 1 is the rock mass around the borehole The maximum principal stress in the plane at any point, MPa; σ 2 is the minimum principal stress in the plane at any point of the rock mass around the borehole, MPa;
同时根据莫尔—库伦屈服条件,即岩体某个平面上的剪应力τn达到极限值时,岩体发生屈服;而该极限值与钻孔周围岩体损伤后的内聚力C、钻孔周围岩体的内摩擦角及钻孔周围岩体在该平面上所受正应力σn有关,公式为:At the same time, according to the Mohr-Coulomb yield condition, that is, when the shear stress τ n on a certain plane of the rock mass reaches the limit value, the rock mass yields; Internal friction angle of rock mass It is related to the normal stress σ n of the rock mass around the borehole on the plane, and the formula is:
式中,τn为钻孔周围岩体在该平面上所受剪应力值,MPa;C为钻孔周围岩体损伤后的内聚力,MPa;σn为钻孔周围岩体在该平面上所受正应力,MPa;为钻孔周围岩体的内摩擦角,度;In the formula, τ n is the shear stress value of the rock mass around the borehole on the plane, MPa; C is the cohesive force of the rock mass around the borehole after damage, MPa; σ n is the rock mass around the borehole on the plane. Under normal stress, MPa; is the internal friction angle of the rock mass around the borehole, degrees;
进一步地,公式(2)、公式(3)和公式(4)联立可得到钻孔周围岩体任意一点的屈服条件式:Further, formula (2), formula (3) and formula (4) can be combined to obtain the yield condition formula of any point of the rock mass around the borehole:
式中,σρ为钻孔周围岩体任意一点处的径向应力,MPa;σθ为钻孔周围岩体任意一点处的环向应力,MPa;τρ为钻孔周围岩体任意一点处的径向剪应力,MPa;C为钻孔周围岩体损伤后的内聚力,MPa;为钻孔周围岩体的内摩擦角,度。In the formula, σ ρ is the radial stress at any point of the rock mass around the borehole, MPa; σ θ is the hoop stress at any point of the rock mass around the borehole, MPa; τ ρ is any point of the rock mass around the borehole The radial shear stress of , MPa; C is the cohesive force of the rock mass around the borehole after damage, MPa; is the internal friction angle of the rock mass around the borehole, degrees.
S4,根据钻孔周围岩体的应力分布规律和弹性理论,钻孔周围岩体的应力状态满足屈服条件时得到钻孔塑性区的发育半径,即联立步骤S2所述公式(1)和步骤S3所述公式(5),得到钻孔周围岩体塑性区的发育半径的计算公式:S4, according to the stress distribution law and elastic theory of the rock mass around the borehole, when the stress state of the rock mass around the borehole satisfies the yield condition, the development radius of the borehole plastic zone is obtained, that is, the formula (1) and the step of step S2 are combined. The formula (5) described in S3, the calculation formula of the development radius of the plastic zone of the rock mass around the borehole is obtained:
式中:R为钻孔周围岩体弹塑性区边界线上的任意一点的极坐标值;ρ为钻孔周围岩体任意一点的极坐标值;a为钻孔半径,mm;C为钻孔周围岩体损伤后的内聚力,MPa;为钻孔周围岩体的内摩擦角,度;P为钻孔所在位置的水平地应力,MPa;In the formula: R is the polar coordinate value of any point on the boundary line of the elastic-plastic zone of the rock mass around the borehole; ρ is the polar coordinate value of any point of the rock mass around the borehole; a is the radius of the borehole, mm; C is the borehole Cohesion of surrounding rock mass after damage, MPa; is the internal friction angle of the rock mass around the borehole, degrees; P is the horizontal in-situ stress at the location of the borehole, MPa;
S5,基于步骤S4所述钻孔塑性区的发育半径,得到密集钻孔弱化顶板孔间距的计算公式为:S5, based on the development radius of the borehole plastic zone described in step S4, the calculation formula for obtaining the spacing between the densely drilled and weakened roof holes is:
L=2Ru (7)L=2Ru (7)
式中,L为密集钻孔弱化顶板孔间距,mm;R为钻孔周围岩体弹塑性区边界线上的任意一点的极坐标值;u为钻孔交界半径放大系数,可根据地质条件的不同取1.2-1.6;In the formula, L is the distance between the holes in the weakened roof of the dense drilling, mm; R is the polar coordinate value of any point on the boundary line of the elastic-plastic zone of the rock mass around the drilling; Different take 1.2-1.6;
有益效果:与现有技术相比,本发明的技术方案具有以下有益的技术效果:Beneficial effects: compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:
本发明提出了一种密集钻孔弱化顶板孔间距的计算方法,基于岩石的弹-脆-塑模型及摩尔库伦准则,计算单孔的塑性区发育情况,并综合考虑多重影响因素,计算得到合适的孔间距,使得密集钻孔岩体的塑性区能相互叠加、互相连通,形成人工岩体结构弱化带,科学有效的解决煤矿深部开采过程中,开采时冲击地压过大的问题;并能够用于放顶煤强制放顶等强矿压问题。The invention proposes a method for calculating the spacing between densely drilled and weakened roof holes. Based on the elastic-brittle-plastic model of rock and the Mohr Coulomb criterion, the development of the plastic zone of a single hole is calculated, and multiple influencing factors are comprehensively considered to obtain a suitable calculation method. The hole spacing of the densely drilled rock mass can be superimposed and connected with each other to form a weakened zone of artificial rock mass structure, which can scientifically and effectively solve the problem of excessive ground pressure during mining in the deep mining process of coal mines; It is used for strong rock pressure problems such as forced top caving caving.
附图说明Description of drawings
图1是密集钻孔弱化顶板切顶卸压方法的钻孔布置平面图;Fig. 1 is the plan view of the drilling arrangement of the method of intensive drilling to weaken the roof cutting and pressure relief;
图2是图1中I-I向剖视图;Fig. 2 is the sectional view of I-I in Fig. 1;
图3是钻孔成像仪示意图;Figure 3 is a schematic diagram of a borehole imager;
图4是原位岩石钻孔剪切仪示意图;Fig. 4 is the schematic diagram of in-situ rock drilling shearing instrument;
图5是水压致裂原位地应力测试系统示意图;Figure 5 is a schematic diagram of a hydraulic fracturing in-situ stress test system;
图6是单个钻孔的围岩的弹塑性区发育图;Fig. 6 is the development diagram of the elastic-plastic zone of the surrounding rock of a single borehole;
图7是密集钻孔弱化顶板构成人工弱化带示意图;Fig. 7 is the schematic diagram of the artificial weakening zone formed by the densely drilled weakened roof;
图中,1-上区段巷道;2-上区段工作面;3-采空区;4-下区段工作面;5-巷道切顶卸压密集钻孔;6-直接顶;7-强制放顶密集钻孔。In the figure, 1- upper section roadway; 2- upper section working face; 3- goaf; 4- lower section working face; 5- roadway roof cutting and pressure relief intensive drilling; 6- direct roof; 7- Forced caving for dense drilling.
具体实施方式Detailed ways
下面结合附图和实施例对本发明的技术方案作进一步的说明。其中,所描述的实施例是本发明一部分实施例,而不是全部的实施例。因此,以下对在附图中提供的本发明的实施例的详细描述并非旨在限制要求保护的本发明的范围,而是仅仅表示本发明的选定实施例。The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments. Herein, the described embodiments are some, but not all, embodiments of the present invention. Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention.
本发明所述的一种密集钻孔弱化顶板孔间距计算方法是密集钻孔顶板弱化的重要参数计算方法。密集钻孔弱化顶板这一技术可应用于坚硬顶板切顶卸压及放顶煤强制放顶等,通过密集钻孔形成人工弱化带,在岩体自重或采动的不平衡高应力影响下,顶板能够沿此弱化带切落或顶煤开始垮落。下面以某矿的地质条件为例对密集钻孔的孔间距进行计算:The method for calculating the hole spacing of the densely drilled weakened roof according to the present invention is an important parameter calculation method for the weakening of the densely drilled roof. The technology of intensive drilling to weaken the roof can be applied to hard roof cutting and pressure relief and forced roof caving, etc. The artificial weakening zone is formed through intensive drilling. The roof can be cut off along this weakened zone or the top coal begins to slump. The following takes the geological conditions of a mine as an example to calculate the hole spacing of dense drilling:
S1,回采工作面布置方式参考图1和图2,为了使回采工作面的直接顶6及时垮落,降低严空巷道的维护难度,选择在上区段工作面巷道沿煤柱一侧的顶板布置巷道切顶卸压密集钻孔5,密集钻孔半径为30mm,巷道切顶卸压密集钻孔5沿着巷道的延伸方向,垂直于巷道直接顶6;若要对工作面放顶煤强制放顶可在回采工作面靠近煤壁处布设强制放顶密集钻孔7。S1, refer to Figure 1 and Figure 2 for the arrangement of the working face. In order to make the direct roof 6 of the working face collapse in time and reduce the maintenance difficulty of the strict-gap roadway, the roof on the side of the coal column in the upper section of the working face is selected. Arrange the roadway roof cutting and pressure relief
S2,对相关顶板围岩在开采扰动影响下岩石力学参数进行准确测量,在超前开切眼5-10m内布设原位测试孔;参考图4,采用井下原位测试系统实测获得巷道开挖后工作面回采影响下,顶板围岩钻孔周围岩体损伤后的内聚力C为1.1MPa、钻孔周围岩体的内摩擦角为30°;参考图5,采用水压致裂原位地应力测试系统得到该矿顶板围岩的地应力为14MPa;参考图3,通过钻孔窥视仪对单一钻孔后一定时间内围岩裂隙发育程度进行分析,参考图7,考虑密集钻孔的群体效应,根据围岩裂隙发育情况及密集钻孔相互耦合作用选定放大系数u取1.5。S2. Accurately measure the rock mechanical parameters of the relevant roof surrounding rock under the influence of mining disturbance, and arrange in-situ test holes within 5-10m of the advance cutting hole; referring to Figure 4, the underground in-situ test system is used to obtain the roadway after excavation. Under the influence of working face mining, the cohesive force C of the damaged rock mass around the roof surrounding rock is 1.1 MPa, and the internal friction angle of the rock mass around the drilling is 1.1 MPa. is 30°; with reference to Figure 5, the in-situ stress of the roof surrounding rock of the mine is 14MPa obtained by the hydraulic fracturing in-situ stress test system; with reference to Figure 3, the surrounding rock within a certain period of time after a single drill hole is drilled through a borehole peep instrument The degree of fissure development is analyzed. Referring to Figure 7, considering the group effect of dense drilling, the amplification factor u is selected to be 1.5 according to the development of fissures in the surrounding rock and the mutual coupling effect of dense drilling.
S3,参考图6,根据钻孔围岩受力情况,设定整个钻孔径向的受力作用一致,以钻孔中心为圆心,建立二维极坐标系;根据弹性力学得到极坐标下钻孔周围岩体中的应力分量公式为:S3, refer to Fig. 6, according to the force of the surrounding rock of the borehole, set the radial force of the entire borehole to be the same, take the center of the borehole as the center of the circle, and establish a two-dimensional polar coordinate system; obtain the polar coordinates according to the elastic mechanics to drill down The formula for the stress component in the rock mass around the hole is:
式中,ρ为钻孔周围岩体任意一点的极坐标值;a为钻孔半径,mm;P为钻孔所在位置的水平地应力,MPa;σρ为钻孔周围岩体任意一点处的径向应力,MPa;σθ为钻孔周围岩体任意一点处的环向应力,MPa;τρ为钻孔周围岩体任意一点处的径向剪应力,MPa;τθ为钻孔周围岩体任意一点处的环向剪应力,MPa;In the formula, ρ is the polar coordinate value of any point of the rock mass around the borehole; a is the radius of the borehole, mm; P is the horizontal in-situ stress at the location of the borehole, MPa; σ ρ is the value of any point of the rock mass around the borehole Radial stress, MPa; σ θ is the hoop stress at any point of the rock mass around the borehole, MPa; τ ρ is the radial shear stress at any point of the rock mass around the borehole, MPa; τ θ is the rock around the borehole hoop shear stress at any point of the body, MPa;
S4,根据平衡条件和莫尔强度条件,基于步骤S3所述参数σρ、σθ和τρ,得到钻孔周围岩体中任意一点所在平面状态的极值应力公式为:S4, according to the equilibrium condition and Moiré strength condition, based on the parameters σ ρ , σ θ and τ ρ described in step S3, the extreme value stress formula of the plane state where any point in the rock mass around the borehole is obtained is:
式中,σ1为钻孔周围岩体任意一点处平面内的最大主应力,MPa;σ2为钻孔周围岩体任意一点处平面内的最小主应力,MPa;σρ为钻孔周围岩体任意一点处的径向应力,MPa;σθ为钻孔周围岩体任意一点处的环向应力,MPa;τρ为钻孔周围岩体任意一点处的径向剪应力,MPa;In the formula, σ 1 is the maximum principal stress in the plane at any point of the rock mass around the borehole, MPa; σ 2 is the minimum principal stress in the plane at any point of the rock mass around the borehole, MPa; σ ρ is the rock around the borehole. radial stress at any point of the body, MPa; σ θ is the hoop stress at any point of the rock mass around the borehole, MPa; τ ρ is the radial shear stress at any point of the rock mass around the borehole, MPa;
进一步地,列出钻孔周围岩体在该平面上所受剪应力值τn和钻孔周围岩体在该平面上所受正应力σn的常用求解公式为:Further, the commonly used solution formula for listing the shear stress value τ n of the rock mass around the borehole on the plane and the normal stress σ n of the rock mass around the borehole on the plane is:
式中,τn为钻孔周围岩体在该平面上所受剪应力值,MPa;σn为钻孔周围岩体在该平面上所受正应力,MPa;σ1为钻孔周围岩体任意一点处平面内的最大主应力,MPa;σ2为钻孔周围岩体任意一点处平面内的最小主应力,MPa;In the formula, τ n is the shear stress value of the rock mass around the borehole on the plane, MPa; σ n is the normal stress of the rock mass around the borehole on the plane, MPa; σ 1 is the rock mass around the borehole The maximum principal stress in the plane at any point, MPa; σ 2 is the minimum principal stress in the plane at any point of the rock mass around the borehole, MPa;
同时根据莫尔—库伦屈服条件,即岩体某个平面上的剪应力达到极限值时,岩体发生屈服;而该极值与钻孔周围岩体损伤后的内聚力C、钻孔周围岩体的内摩擦角及钻孔周围岩体在该平面上所受正应力σn有关,公式为:At the same time, according to the Mohr-Coulomb yield condition, that is, when the shear stress on a certain plane of the rock mass reaches the limit value, the rock mass yields; angle of internal friction It is related to the normal stress σ n of the rock mass around the borehole on the plane, and the formula is:
式中,τn为钻孔周围岩体在该平面上所受剪应力值,MPa;C钻孔周围岩体损伤后的内聚力,MPa;σn为钻孔周围岩体在该平面上所受正应力,MPa;为钻孔周围岩体的内摩擦角,度;In the formula, τ n is the shear stress value of the rock mass around the borehole on the plane, MPa; C is the cohesive force of the rock mass around the borehole after damage, MPa; σ n is the rock mass around the borehole on this plane. Normal stress, MPa; is the internal friction angle of the rock mass around the borehole, degrees;
进一步地,公式(2)、公式(3)和公式(4)联立可得到钻孔周围岩体任意一点的屈服条件式:Further, formula (2), formula (3) and formula (4) can be combined to obtain the yield condition formula of any point of the rock mass around the borehole:
式中,σρ为钻孔周围岩体任意一点处的径向应力,MPa;σθ为钻孔周围岩体任意一点处的环向应力,MPa;τρ为钻孔周围岩体任意一点处的径向剪应力,MPa;C钻孔周围岩体损伤后的内聚力,MPa;为钻孔周围岩体的内摩擦角,度。In the formula, σ ρ is the radial stress at any point of the rock mass around the borehole, MPa; σ θ is the hoop stress at any point of the rock mass around the borehole, MPa; τ ρ is any point of the rock mass around the borehole radial shear stress of , MPa; cohesive force of rock mass around borehole C after damage, MPa; is the internal friction angle of the rock mass around the borehole, degrees.
S5,根据钻孔周围岩体的应力分布规律和弹性理论,钻孔周围岩体的应力状态满足屈服条件时得到钻孔塑性区的发育半径,即联立步骤S3所述公式(1)和步骤S4所述公式(5),得到钻孔周围岩体塑性区的发育半径的计算公式:S5, according to the stress distribution law and elasticity theory of the rock mass around the borehole, when the stress state of the rock mass around the borehole satisfies the yield condition, the development radius of the borehole plastic zone is obtained, that is, the formula (1) and the step of step S3 are combined. The formula (5) described in S4, the calculation formula of the development radius of the plastic zone of the rock mass around the borehole is obtained:
式中:R为钻孔周围岩体弹塑性区边界线上的任意一点的极坐标值;ρ为钻孔周围岩体任意一点的极坐标值;a为钻孔半径,mm;C钻孔周围岩体损伤后的内聚力,MPa;为钻孔周围岩体的内摩擦角,度;P为钻孔所在位置的水平地应力,MPa;In the formula: R is the polar coordinate value of any point on the boundary line of the elastic-plastic zone of the rock mass around the borehole; ρ is the polar coordinate value of any point of the rock mass around the borehole; a is the radius of the borehole, mm; C around the borehole Cohesion of rock mass after damage, MPa; is the internal friction angle of the rock mass around the borehole, degrees; P is the horizontal in-situ stress at the location of the borehole, MPa;
S6,基于步骤S5所述钻孔塑性区的发育半径,得到密集钻孔弱化顶板孔间距的计算公式为:S6, based on the development radius of the drilling plastic zone described in step S5, the calculation formula for obtaining the spacing between the holes of the densely drilled weakened roof is:
L=2Ru (7)L=2Ru (7)
式中,L为密集钻孔弱化顶板孔间距,mm;R为钻孔周围岩体弹塑性区边界线上的任意一点的极坐标值;u为钻孔交界半径放大系数,本式u取值1.5;In the formula, L is the distance between the holes in the weakened roof of the dense drilling hole, mm; R is the polar coordinate value of any point on the boundary line of the elastic-plastic zone of the rock mass around the drilling hole; u is the magnification factor of the boundary radius of the drilling hole, which is the value of u in this formula 1.5;
基于步骤S5所述参数R和步骤S6所述参数u,计算得到密集钻孔弱化顶板孔间距L=119mm,由于工程施工中存在一定误差,考虑到容差,密集钻孔选择110-130mm为钻孔间距。Based on the parameter R described in step S5 and the parameter u described in step S6, the distance L=119mm between the holes in the weakened roof of the dense drilling is calculated. Due to certain errors in the engineering construction, considering the tolerance, the dense drilling is selected as 110-130 mm. hole spacing.
Claims (5)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010945806.3A CN112115599B (en) | 2020-09-10 | 2020-09-10 | A method for calculating the spacing between densely drilled and weakened roofs |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202010945806.3A CN112115599B (en) | 2020-09-10 | 2020-09-10 | A method for calculating the spacing between densely drilled and weakened roofs |
Publications (2)
Publication Number | Publication Date |
---|---|
CN112115599A true CN112115599A (en) | 2020-12-22 |
CN112115599B CN112115599B (en) | 2022-09-30 |
Family
ID=73803140
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202010945806.3A Active CN112115599B (en) | 2020-09-10 | 2020-09-10 | A method for calculating the spacing between densely drilled and weakened roofs |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN112115599B (en) |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040040717A1 (en) * | 2002-07-08 | 2004-03-04 | Hill Gilman A. | Method for upward growth of a hydraulic fracture along a well bore sandpacked annulus |
CN204419145U (en) * | 2014-12-29 | 2015-06-24 | 西安科技大学 | Coal seam liquid carbon dioxide fracturing device |
CN106528963A (en) * | 2016-10-21 | 2017-03-22 | 河南理工大学 | Design method for row space between pressure relief boreholes |
CN107067333A (en) * | 2017-01-16 | 2017-08-18 | 长沙矿山研究院有限责任公司 | A kind of high altitudes and cold stability of the high and steep slope monitoring method |
CN108920851A (en) * | 2018-07-10 | 2018-11-30 | 山东科技大学 | A kind of destressing borehole spacing based on target support pressure determines method |
CN108951940A (en) * | 2018-07-20 | 2018-12-07 | 中国地震局工程力学研究所 | A kind of frame wall filled with masonry and the practice discharging attachment device certainly using stress |
CN110219592A (en) * | 2019-05-27 | 2019-09-10 | 中国矿业大学(北京) | A kind of cubic network destressing borehole method for arranging for realizing the abundant release of high seam |
CN111520183A (en) * | 2020-05-13 | 2020-08-11 | 安徽理工大学 | Method for treating gas generated by mining, blasting, roof cutting, pressure relief and permeability improvement of coal seam group under thick-layer sandstone |
CN111577232A (en) * | 2020-05-21 | 2020-08-25 | 重庆市能源投资集团科技有限责任公司 | Coal mine underground fracturing control safety guarantee method |
-
2020
- 2020-09-10 CN CN202010945806.3A patent/CN112115599B/en active Active
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20040040717A1 (en) * | 2002-07-08 | 2004-03-04 | Hill Gilman A. | Method for upward growth of a hydraulic fracture along a well bore sandpacked annulus |
CN204419145U (en) * | 2014-12-29 | 2015-06-24 | 西安科技大学 | Coal seam liquid carbon dioxide fracturing device |
CN106528963A (en) * | 2016-10-21 | 2017-03-22 | 河南理工大学 | Design method for row space between pressure relief boreholes |
CN107067333A (en) * | 2017-01-16 | 2017-08-18 | 长沙矿山研究院有限责任公司 | A kind of high altitudes and cold stability of the high and steep slope monitoring method |
CN108920851A (en) * | 2018-07-10 | 2018-11-30 | 山东科技大学 | A kind of destressing borehole spacing based on target support pressure determines method |
CN108951940A (en) * | 2018-07-20 | 2018-12-07 | 中国地震局工程力学研究所 | A kind of frame wall filled with masonry and the practice discharging attachment device certainly using stress |
CN110219592A (en) * | 2019-05-27 | 2019-09-10 | 中国矿业大学(北京) | A kind of cubic network destressing borehole method for arranging for realizing the abundant release of high seam |
CN111520183A (en) * | 2020-05-13 | 2020-08-11 | 安徽理工大学 | Method for treating gas generated by mining, blasting, roof cutting, pressure relief and permeability improvement of coal seam group under thick-layer sandstone |
CN111577232A (en) * | 2020-05-21 | 2020-08-25 | 重庆市能源投资集团科技有限责任公司 | Coal mine underground fracturing control safety guarantee method |
Non-Patent Citations (3)
Title |
---|
JIANGWEI LIU 等: "Mechanisms of crack initiation and propagation in dense linear multihole directional hydraulic fracturing", 《SHOCK AND VIBRATION》 * |
刘天啸: "高应力巷道钻孔卸压机理及让压支护技术研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅰ辑》 * |
杨敬轩 等: "围岩孔裂隙充水承压爆破过程分析", 《中国矿业大学学报》 * |
Also Published As
Publication number | Publication date |
---|---|
CN112115599B (en) | 2022-09-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN110985058B (en) | Grouting reinforcement method for fault fracture zone of coal face | |
CN112780340B (en) | Method for preventing rock burst in advance in underground coal mine area | |
CN110397470A (en) | A method for determining the reasonable width of narrow coal pillars in gob-side entry based on fracture evolution | |
CA3084096A1 (en) | Fracturing relief method for stress concentration of remaining ore pillars in overlying goaf | |
CN112377193B (en) | Deep well small coal pillar gob-side entry retaining method based on top breaking and pressure relief of lower key layer of top plate | |
CN114251103B (en) | A kind of directional slitting fracturing roof roadway anti-scour roadway protection method and safe mining method | |
CN111255463A (en) | Hard top plate comb-shaped long drilling segmented fracturing roadway deformation source treatment method | |
CN110792419B (en) | A method for advance pre-control of up and down wells in coal mine rock burst | |
CN112160792B (en) | Staged hydraulic fracturing working method for underground hard top plate | |
CN110966002B (en) | A method of roof cutting and pressure relief based on dense drilling | |
CN105909284B (en) | A kind of high working face coal wall caving prevents control method | |
CN113622913A (en) | Deformation control method for mining tunnel surrounding rock integrated with underground and up-down tunnel by full-caving method | |
CN117345237B (en) | Method for lowering suspended top coal at end of coal face by combining hydraulic coal drawing and slotting | |
CN109681180A (en) | Coal mine ground vertical well pressure break tight roof controls the strong mine of stope and presses effect pre-evaluation method | |
CN113250613B (en) | Investigation method of directional drilling along coal seam in goaf of small coal kiln | |
CN116291186A (en) | Deep high-ground-stress roadway surrounding rock drilling pressure relief structure and effect evaluation method thereof | |
CN109098711A (en) | It is a kind of to block the heavily stressed method in ore body top using pressure relief groove | |
CN104805830A (en) | Uplift pile construction method without rock blasting | |
CN112031772B (en) | Method for inducing overall damage of overlying residual coal pillars by using high-pressure water jet | |
CN118656987A (en) | Directional long drilling and coordinated fracturing arrangement method and system for deep coal seam composite roof | |
CN112115599B (en) | A method for calculating the spacing between densely drilled and weakened roofs | |
Qin et al. | Stability and control of retracement channels in thin seam working faces with soft roof | |
CN117328871A (en) | A method for linking instability hydraulic fracturing of the T-shaped structure of the remaining coal pillars | |
CN108643909B (en) | A kind of working face extraction tunnel initating optimization of region method | |
CN110043262A (en) | A kind of coal mine tight roof fractured horizontal well crack well combines monitoring method up and down |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |