摘要
滑坡是一种常见的地质灾害,对其监测、预报越来越受到人们的重视,但在一些特殊地区,特别是在一些山区,受地形和通视条件的影响,滑坡监测网的布设受到很大限制。这样就需对所布设的监测网进行质量分析和优化设计。从经济指标考虑,采用常规监测网与基准网的布设,有成熟的作业规程,但是由于区域条件的限制,测角监测网无法满足规范中对交会角条件的要求,另外鉴于高精度的测距仪测边精度很高,故该监测网观测方案首先采用测边交会。选取网中图形条件最差的两个点,对其在该方案下的点位精度、网形的内外可靠性以及灵敏度进行了理论分析和实际计算,根据计算结果显示个别边可靠性差的情况,分析了其原因。综合考虑经济指标和质量指标,提出了对观测方案的优化措施,在网形的关键部位加测角度,测角精度为2″.5,改进后的方案既保证了必要的点位精度和灵敏度,且网形的可靠性得到明显提高,对监测网进行优化设计是必要的和有效的。
Landslide is one of the common geological hazards. So it is becoming more and more important to monitor and forecast it. However, the design of monitoring net is always confined by topography and poor visibility especially. in mountainous areas. Therefore, it is necessary to analyze the qualify the index of the monitoring net in those conditions and optimize it.By considering the economic index, the traditional design method of monitoring net and base net for their mature operation are usually adopted. However, for the poor condition mentioned above, the monitoring net with angle observation can not satisfy the minimum angle in surveying criterion. On the other hand, considering that the total station has high precise on line surveying, we adopted to survey the lines, analyzed and calculated internal and external reliabilities and sensitivities of the two typical points which precisions is lowest. We analyzed the reason why the line is poor reliable according to the result calculated. And we bring out the way to design an optimized method according to the economic and quality index. This method is to observe an angle related to this line with 2.5' precision additionally. It is proved that the reliability has been increased greatly So, it is necessary and effective to optimize the monitoring net.
