开采影响地表点变形状态分析及主变形值计算

Mining influenced ground deformation state analysis and principal deformation calculation

为准确掌握地下开采造成的地表点在任意方向上的移动变形状态及主变形值大小,基于概率积分法基本原理分析了地表点在开采影响下的移动变形状态,建立了地表主变形及其方向的计算方法;采用"应变花"思想,构建了已知任意2个不同方向地表倾斜、水平移动计算地表任意方向的倾斜、水平移动及其主变形值和方向的计算模型以及已知任意3个不同方向的曲率、水平变形值计算该点在平面上任意方向的曲率、水平变形、扭曲、剪切及其主变形值和方向的公式。以2个计算案例说明了公式的使用方法及采用地表移动最大值进行建筑物影响等级判断的重要性。"应变花"算法可以计算地表点任意方向的平面变形状态,易于与现有开采沉陷预计程序结合,对准确掌握开采地表移动变形情况、建(构)筑物损害评估及采空区上方抗变形建筑物设计具有指导意义。

For the accurate state of ground points＇ displacement and deformation at arbitrary direction caused by underground mining and its principal deformation values, the displacement and deformation state of ground points was analyzed based on probability integration method, and the calculation method was established for principal deformation and its direction of ground points. Based on ＂strain rosette＂ method, formulas to calculate arbitrary directions tilt, horizontal movement and its principal direction using two different direction tilt and horizontal movement were derived, also formulas to calculate arbitrary directions curvature, horizontal deformation, distortion and shear and its principal direction using three different direction curvature, horizontal deformation were derived as well. An example of using the formula was described. Another actual ground subsidence prediction was shown to indicate the importance of building impact assessment using the maximum values of ground deformation. The calculation method of ＂strain rosette＂ can help work out the surface deformation law clearly and it has practical significance for accurate mining subsidence prediction, building damage assessment and resistance deformation design for buildings over mined goaf.