针对现有基于点云的容量计量模型的缺陷,本文提出一种改进的洞库容量计量模型。首先,在高度方向上将洞库点云数据由下至上切割为若干微元体;采用提出的分层投影法准确地提取截面轮廓点,基于改进的截面轮廓点排序算法正确地构建截面轮廓多边形,使用坐标解析法计算截面积;考虑洞库的构造特点,分别采用柱体模型与棱台模型计算洞库的下部边墙及上部拱顶的微元体体积;最后,由下至上累加微元体的体积即可获取洞库容量表。选用三个具备代表性的洞库片段数据进行方法验证,实验所得洞库容量表的精度优于规范要求1个数量级,说明本文方法对复杂的洞库结构具有良好的适应性。

In this study, we propose an improved cavern capacity calculation model to address the defects of existing point cloud methods. First, the cavern preprocessed point cloud is sectioned into several point cloud slices from the bottom to the top along the height direction. For each slice, the contour points of two cross sections are extracted using the presented hierarchical projection method,and the section contour polygon is constructed correctly by using the improved ordering algorithm for section contour points. Subsequently, the area of each cross section is calculated using the coordinate analytic method. Given the structures of the caverns, the cell volumes of the lower side wall and upper arch of caverns are calculated by using models of cylinder and trustum of a pyramid, respectively. Finally, the capacity table of the caverns can be acquired based on the volume of every polyhedron from the bottom to the top. The performance of the proposed method is evaluated using three representative point cloud fragments from a cavern. The results denote that the accuracy of the output capacity table obtained by experiments is an order of magnitude higher than that demanded by the standard requirement. The proposed approach shows good adaptability with respect to the complex structure of caverns.