为监视大坝安全运行和收集用于验证水工设计参数的资料,必须进行大坝外部变形观测。外部变形观测控制网不同于施工控制网,更不同于国家大地测量控制网,因此,应按照特定的要求,因地制宜地优选合适的专用控制网,作为设计变形观测控制网。下面分别对变 In order to monitor the safe operation of the dam and collect information used to verify the hydraulic design parameters, external deformation monitoring of the dam is necessary. External deformation observation control network is different from the construction control network, more different from the national geodetic control network, therefore, should be in accordance with specific requirements, according to local conditions to optimize the appropriate special control network, as the design of deformation observation control network. The following were changed