【摘要】：大采高開采技術實現了工作面高產高效,但是煤壁穩(wěn)定性問題制約了其安全高效生產。本論文采用理論分析、現場研究以及數值模擬相結合的方法,主要研究了大采高工作面煤壁在多因素作用下失穩(wěn)特征及機理。重點研究了割煤高度、工作面長度、工作面推進速度、支架支護強度、支架護幫板支護強度、頂板強度、煤層強度、煤層埋深及煤層仰角對工作面煤壁穩(wěn)定性的影響。采用數值模擬從剩余能量角度分析了工作面煤壁穩(wěn)定性的主要影響因素。采用正交試驗和回歸分析得到了大采高工作面穩(wěn)定性評價公式及評價指標,驗證了 8303工作面失穩(wěn)可能性。結合現場研究和數值模擬,研究了 8303工作面煤壁失穩(wěn)特征及機理�；诖蟛筛吖ぷ髅婷罕谑Х�(wěn)特征及機理,提出了大采高工作面穩(wěn)定性控制技術措施。主要結論如下:(1)割煤高度、工作面長度、工作面推進速度、支架支護強度、支架護幫板支護強度、頂板強度、煤層強度、煤層埋深、煤層仰角及斷層對工作面煤壁穩(wěn)定性有影響,主要影響因素為割煤高度、工作面推進速度、煤層強度和煤層埋深,其顯著性順序為煤層強度煤層埋深割煤高度推進速度。(2)割煤高度、工作面推進速度、煤層硬度和煤層埋深與煤壁穩(wěn)定性呈冪函數關系,多因素綜合影響下工作面煤壁穩(wěn)定性評價公式為Y =-9E7 + 4.01E7f-1.526 + 0.233H2 8011 + 4.62E5M2.4641 + 9.66E3V1.4972 ≤ 107J,驗證了 8303工作面失穩(wěn)的可能性。(3)8303工作面煤壁的失穩(wěn)形式以中部煤層拉裂式片幫引發(fā)上部煤層剪切式片幫的復合式片幫為主。(4)中部煤層拉裂式片幫的破壞條件為及≤Rt≤2KP/πRarcsinb/R);上部煤層剪切片幫的失穩(wěn)條件為Ch sec α+[QL+γ(2h-H+b/2L-H-b/2 tan α)](sin α tan φ-cos α)≤ 0。(5)復合式片幫主要與煤體的粘聚力、內摩擦角、抗拉強度、抗剪強度、煤體性質以及頂板壓力有關。采用提高煤層強度、減小煤層割煤高度、加快煤層推進速度、加強支護管理保證支架支護強度、加強頂板管理、設計時避免煤層仰斜開采等措施改善頂板壓力,減少其回轉下沉量,有利于提高煤壁穩(wěn)定性。
[Abstract]:The mining technology of large mining height has realized the high yield and high efficiency of coal face, but the stability of coal wall restricts its safe and efficient production. In this paper, theoretical analysis, field study and numerical simulation are used to study the instability characteristics and mechanism of coal wall in large mining face under the action of many factors. The influences of coal cutting height, working face length, working face advance speed, support strength, roof strength, coal seam depth and elevation angle on the stability of coal face wall are studied. The main influencing factors of coal wall stability in coal face are analyzed by numerical simulation from the angle of residual energy. By using orthogonal test and regression analysis, the evaluation formula and evaluation index of the stability of large mining face are obtained, and the possibility of instability in 8303 face is verified. Combined with field research and numerical simulation, the characteristics and mechanism of coal wall instability in 8303 face are studied. Based on the characteristics and mechanism of coal wall instability in large mining face, the technical measures of stability control in large mining face are put forward. The main conclusions are as follows: (1) the height of coal cutting, the length of working face, the speed of working face, the strength of support, the strength of roof, the depth of coal seam, The coal seam elevation angle and fault have influence on the stability of coal face wall. The main influencing factors are cutting height, working face advancing speed, coal seam strength and coal seam depth. The significant order is the advancing speed of cutting height of coal seam. (2) the height of cutting coal, the speed of coal face advancing, the hardness of coal seam and the depth of coal seam burying have power function relation with the stability of coal wall. Under the influence of multiple factors, the formula for evaluating the stability of coal face wall is Y / 9E7 4.01E7f-1.526 0.233H2 8011 4.62E5M2.4641 9.66E3V1.4972 鈮，

本文編號：2168525