二等水准测量 meaning in English

second order leveling
second-order levelling

Specification for the first and second order leveling
国家一二等水准测量规范
Firstly , for normal high building , second - class measurement could meet the needs of sinking survey ; secondly , the location of survey should be based on the design drawing and choosing the first structure layer as a survey period ; thirdly , the arrangement of the results of sinking survey should be regular and accurate by a certain person , and if there is problem present , it should be solved or done away with in time ; finally , the results of building sinking survey should be fed back in time to survey , design and construction units as reference for the next project
首先对一般的高层建筑物来说，只需二等水准测量即可满足沉降观测的要求；其次，对于沉降观测点及观测的周期，通常要按照设计图纸的要求布设观测点，观测的周期一般以一个结构层为一个观测周期；第三，对沉降观测结果的整理，要定期定人及时准确，发现问题要及时解决处理；最后，建筑物沉降观测的结果要及时反馈给勘察、设计和施工单位，为下一步的勘察、设计和施工提供可靠的参考依据。