定期观测 meaning in Chinese

periodic measurement
periodic observation
regular observation

The data captured in field tests and observations both prove that crossrange prestressing can effectively reduce roadbed settlement , shorten the roadbed compression and stabilization period , and increase the capacity of roadbed
通过试验路段的试验以及竣工后一段时间的定期观测，表明侧向施加的预应力能减少路堤总沉降，缩短工后沉降稳定期，提高路堤的承载力。
Answer : according to ranking regulation , to the disease of bridge sui , wadi foundation of stage of change , mound erodes adjustable adjuster undertakes circumstance and rail fixed observation , fill in " adjustable adjuster observation records rail book "
答：按照上级规定，对桥隧的病害、河道变化、墩台基础冲刷情况及钢轨伸缩调节器进行定期观测，填写《钢轨伸缩调节器观测记录簿》。