露天矿边坡监测大气竖直折光系数模型及其影响因素研究

Slope monitoring data are the important data source for forecasting the slope instability of open-pit mine . Due to the atmospheric refraction , the trigonometric leveling data are of low precision and stability based on high-precision total station instruments, which is the bottleneck to forecast the slope instability. Studying the vertical refraction modeling based on the optical transmission refraction theory in atmosphere is the solution to the key problem effectively. In the our present study ,on the basis of parameters experiment method preliminary designed to collect atmospheric refraction influencing factors under open-pit mine environment ,and modeling method for establish optical path curve from the ground elevation , with the on-site data as data source, the changing rule of atmospheric refraction factors is revealed , temperature gradient, barometric gradient, humidity gradient, vapor pressure gradient model etc. are established under the open pit mine environment , based on the atmospheric refraction model, the atmospheric vertical refraction model is built in open pit mine environment. Elevation difference of verification line is calculated by using of the monitoring data and model established. it is compared with the elevation difference acquired by high grade level to complete the correction of the model coefficient, and to answer a question of the key problem of elevation uncertainty in slope monitoring with high precision total station instruments ,which has practical significance for correctly forecasting the slope instability of open-pit mine.

露天矿边坡监测数据是开展露天矿边坡失稳预测、预报的重要数据源。然而由于大气折光的影响，基于高精度全站仪三维监测系统存在三角高程测不准的问题，其已成为边坡失稳准确预测、预报的瓶颈。开展以大气折光理论模型为基础的大气竖直折光系数建模研究，是解决这一关键问题的有效途径。本研究在我们前期提出采集露天矿环境下的大气折光影响因素物理量实验方法、建立光径曲线距地面高差模型方法研究基础上，以现场采集的数据为数据源，揭示大气折光因素物理量的变化规律，建立露天矿环境下的温度、气压、湿度、水汽压等梯度模型，以大气折射理论模型为基础，建立露天矿环境的大气折光系数模型。利用已建立的模型和监测基础数据计算验证线路的高差，将其与通过高等级水准获得的高差进行比较完成对模型相关系数的修正。以此解决基于高精度全站仪露天矿边坡监测高程测不准的关键问题。其对露天矿边坡失稳的准确预测、预报具有现实意义。

本研究针对基于高精度全站仪组成的三维监测系统存在三角高程测不准的关键问题，依托鞍山眼前山、大孤山和鞍千露天铁矿建立了三个实验场，并采集了45个周期的实验数据，分析了露天矿环境影响大气折光的显著性物理量，揭示大气折光因素物理量随高度的变化规律，建立露天矿环境下的温度、气压和相对湿度的梯度模型，以三维激光扫描仪采集的露天采场数据为数据源建立了交痕曲线模型和测距光径距地表的高差模型，并以以大气折射理论模型为基础，建立露天矿环境的大气折光系数模型。利用已建立的模型和监测基础数据计算了多条验证线路的高差，并以国家一等水准联测高差为真值对模型的相关系数进行了修正，同时也验证了模型的可靠性。研究结果对提高基于高精度全站仪露天矿边坡高程监测数据精度的方法提供参考，对基于位移数据的露天矿边坡稳定性分析与预警技术研究具有重要的现实意义。