针对煤巷倾斜层状顶板的结构特点,建立煤巷倾斜顶板的简支梁力学模型,推导顶板挠曲线的计算公式和巷道顶板最大下沉位置。结果表明:倾斜层状顶板最大下沉位置不在巷道中心线上,而是向巷道底帮偏移;影响倾斜巷道顶板下沉曲线的因素主要有顶板岩层弹性模量、岩层厚度、顶板关键层位置、巷道宽度和顶板倾斜角度,其中弹性模量和岩层厚度仅影响顶板下沉量,但不影响顶板最大下沉位置,而关键层位置、巷道宽度和顶板倾斜角度对两者均产生影响;随着关键层与顶板距离的增大,最大下沉位置向巷道中心线移动;随着巷道宽度和顶板倾斜角度的增大,顶板最大下沉位置均向巷道底帮移动。现场工业性试验的实测结果较好地验证了理论推导的结果,因此,建议将顶板中部锚索位置整体向巷道底帮偏移10-30cm,以便更好实现顶板变形控制。
For structural features of tilt layered roof in coal tunnel, it was established a mechanical model of simply supported beam from the tilt roof, and it was derived the roof deflection curve formula and the maximum subsidence location in the roof. The results show that tilt layered roof maximum subsidence location is not at the center line of the tunnel, but offsets to the tunnel lower side; the influence factors of roof deflection curve mainly include roof strata elastic modulus,bed thickness,roof key stratum position,tunnel width and roof tilt angle.The elastic modulus and bed thickness simply affect the roof subsidence, but hardly affect the maximum subsidence location. However,roof key stratum position,tunnel width and roof tilt angle have influences upon the roof subsidence and the maximum subsidence location. With the distance increasing between critical strata and the roof, the maximum subsidence location offsets to the center line of the tunnel. With the increasing of the tunnel width and roof tilt angle,the maximum subsidence location moves to the tunnel lower side. The theoretical results are validated by the measured results from the industrial test. In order to achieve a better roof deformation control,it is recommend that the central roof anchors location overall offset to the tunnel lower side 10 -30cm.