【《巷道交岔点支护施工工程应用与现场监测方案案例》2200字】

巷道交岔点支护施工工程应用与现场监测方案案例目录TOC\o"1-3"\h\u10385巷道交岔点支护施工工程应用与现场监测方案案例 1103261.1现场监测目的 1224741.2监测内容与方法 1183901.2.1表面位移监测 272751.2.2锚杆锚索轴力监测 31.1现场监测目的潘三煤矿东一采区2121（3）轨顺进料巷1-1断面②~③施工段巷道交岔点采用“深层注浆+锚杆锚索”支护方案。为反馈该支护方案应用效果，通过现场监测研究顶底板、两帮变形及破坏规律。研究巷道顶部及左右两帮锚杆、锚索轴力的轴力变化分布规律。通过监测数据反馈交岔点巷道支护参数的合理性，为类似巷道交岔点支护施工提供设计依据。1.2监测内容与方法（1）监测内容①表面位移观测；②锚杆锚索轴力观测。（2）测站布置依据理论与数值模拟结果，针对2121（3）轨顺进料巷交岔点采用“深层注浆+锚杆锚索”支护方案，为检验优化方案和应用效果，在该巷道交岔点布置测量测点，共布置2个测站，主要测量表面位移及锚杆锚索受力情况，两个测站分别距交岔点3m和5m，随着主巷和支巷掘进，收集两个测站测点的变形及应力变化情况，各个测站位置及具体布置如图41示。图412121（3）轨顺进料巷交岔点测站布置图Fig.412121(3)Layoutofthestationatthecrossingpointoftherailfeedlane1.2.1表面位移监测表面位移监测可以直观地表现出顶底板、两帮变形量的大小。直接观测内容包括两帮变形量、顶底板变形量，通过这些数据可以判断巷道围岩的变形量是否超过其最大安全允许值，是否影响巷道的正常使用。进而可以对巷道支护效果做出一定评估，保证后续支护效果达到理想状态。从而判断围岩巷道围岩是否处于安全允许的范围内。评估交岔巷道锚网索+注浆联合技术的支护效果。表面位移观测通常采用十字断面法进行，观测仪器常采用特制带铁棒点测托板结合激光测距仪进行，监测点布置示意图如图42所示。图42“十字”布点法示意图Fig.42"Cross"layoutmethodschematicdiagram在巷道掘进过程中对潘三煤矿东一采区2121（3）轨顺进料巷1-1断面②~③施工段巷道测站进行变形监测。监测结果如图43所示。(a)测站一位移量(b)测站二位移量图43各测站巷道围岩位移量Fig.43Displacementofroadwaysurroundingrockateachmeasuringstation由图43a、图43d可知，随着巷道施工的进行，巷道顶板中点处的位移变化先快后慢，最终趋于稳定。巷道施工后3天，巷道变形速率高达10.77mm/d；施工33天后，速率降为1.1mm/d；35天后巷道基本趋于稳定。两个测站监测结果巷道围岩累计顶底板移近量为192.7mm，两帮收缩量为160.3mm，巷道变形量小，支护效果较好，从而上表明方案7的实际应用效果较好。1.2.2锚杆锚索轴力监测对于两个测站分别设置锚索锚杆轴力计，每个断面布置2个锚索轴力计分别布置在巷道左右肩窝处，布置3个锚杆轴力计，分别位于巷道顶板与左右帮部，具体布置图如图44所示。其中测站一测点对应S1、S2，G1、G2和G3，测站二对应S3、S4，G4、G5和G6。锚索锚杆轴力计如图47所示，随着巷道掘进测量工作由10月25日开始观测。根据观测数据并进行整理，得出巷道掘进期间各个测点锚杆（索）压力变化情况。图44锚杆锚索轴力计布置图Fig.44Layoutofmeasuringpointsofstation1图45振弦式锚杆锚索测力计Fig.45Boltcabledynamometer根据上述测点的监测情况，可以得到2121（3）轨顺进料巷交岔点处锚杆、锚索的轴力变形情况，如表6、表7所示。表6测站一锚杆锚索轴力值Table6Internalforcevalueofanchorrodandcableofpoint1测点日期S1轴力/kNS2轴力/kNG1轴力/kNG2轴力/kNG3轴力/kN2019.10.2534.3441.8222.75922.19321.3792019.10.2643.5249.91221.12221.05931.7972019.10.2751.06857.18829.41429.93634.7722019.10.2854.80861.33631.77931.40034.4812019.10.2958.61656.84839.25032.55839.9652019.10.3060.58868.61241.32431.30242.2402019.10.3151.89669.56443.59037.49742.3572019.11.0161.271.1441.27839.32643.9902019.11.0264.32883.77643.49441.54547.8992019.11.0476.8491.52848.41243.22851.6922019.11.0673.71296.01653.13853.34953.9092019.11.0881.95291.86862.92651.30061.7272019.11.1091.93698.66870.06253.89763.3602019.11.1297.988110.70472.61859.62966.8022019.11.1496.356111.9469.67764.14064.5272019.11.1694.248108.86882.21462.25067.2692019.11.1897.104134.6487.08470.48170.8862019.11.20109.616120.56489.92970.23771.4952019.11.22111.804126.54891.85874.68881.4722019.11.24116.688137.97294.75182.24891.2482019.11.26122.604151.584101.50189.62689.3812019.11.29138.856149.668106.32392.79696.3822019.12.02144.636156.468113.50896.51598.8332019.12.04148.376167.008119.294102.917103.9672019.12.06146.268168.64118.426101.112104.7252019.12.08147.492164.016116.353103.527102.2162019.12.09158.984170.612121.753107.246106.0672019.12.11161.5162.18123.586109.258102.6252019.12.15161.092167.144120.693101.844104.0832019.12.19161.364168.504123.972106.515106.0092019.12.23162.86166.192123.200101.600103.500表7测站二锚杆锚索轴力值Table7Internalforcevalueofanchorrodandcableofpoint2测点日期S3轴力/kNS4轴力/kNG4轴力/kNG5轴力/kNG6轴力/kN2019.10.2531.7136.4023.5623.5623.562019.10.2634.3942.5626.7932.1029.452019.10.2741.4047.6532.1033.8631.632019.10.2847.2850.7641.4838.3839.712019.10.2948.0354.1647.1742.7644.532019.10.3053.1650.5453.2048.7748.772019.10.3157.9457.8459.8254.9654.072019.11.0159.6960.8456.8151.0257.232019.11.0259.5363.6761.0460.1961.512019.11.0467.4172.3864.3662.1663.042019.11.0672.1572.0469.2568.8166.162019.11.0881.5787.7871.8467.8661.662019.11.1093.6081.4680.4671.6174.722019.11.1296.5494.8586.5371.6374.282019.11.1497.0694.9191.2471.6179.142019.11.16101.13106.5193.7971.6380.022019.11.18104.96111.6296.2171.6180.462019.11.20110.53117.4399.2684.4479.582019.11.22128.60120.32100.2487.9786.652019.11.24130.83137.86106.9581.7681.322019.11.26140.09149.18108.9096.3692.832019.11.29144.39151.12111.8691.0491.502019.12.02151.35160.50117.9997.2497.682019.12.04164.43168.08117.7391.4898.132019.12.06161.54170.91118.62101.2299.452019.12.08161.53162.42122.7091.0494.152019.12.09166.10167.06119.6999.4596.802019.12.11168.60171.08123.586109.258102.6252019.12.15162.94173.63120.693101.844104.0832019.12.19168.55173.97123.972106.515106.0092019.12.23166.36168.02123.200101.600103.500将上述锚杆锚索轴力值的现场监测数据与数值模拟结构进行对比，如图46~图47所示。(a)S1测点轴力值(b)S2测点轴力值(c)S3测点轴力值(d)S4测点轴力值图46各测点锚索轴力变化图Fig.46Variationdiagramofanchorcableaxialforceateachmeasuringpoint(a)G1测点轴力值(b)G2测点轴力值(c)G3测点轴力值(d)S3测点轴力值(e)G5测点轴力值(f)S6测点轴力值图47各测点锚杆轴力变化图Fig.47Variationdiagramofanchorboltaxialforceateachmeasuringpoint由表6、表7可知从锚杆轴力变化曲线斜率上看，测站在前20~25天，锚杆压力变化速率较大；超过25天后，锚杆轴力变化速率逐渐变小，最后趋于稳定。锚杆轴力值在100-120kN之间，锚索轴力值最大为178kN左右。锚杆锚索轴