The temporary support technology of pre-support in tunnel is introduced. Its advantages and disadvantages are analyzed.
介绍了当前隧道超前预支护技术的现状，分析了其优缺点。
2
In order to control the subsidence of the interval tunnel and guarantee the safety of operation strictly, pipe-jacking is used as pre-support for the first time.
为了严格控制既有环线区间隧道的沉降，确保环线地铁运营安全，首次采用了顶管作超前预支护。
3
In order to limit the sink of surface and maintain the stratum stable, it's necessary to do pre-support and consolidation, when tunnels would be constructed in soft or weak geology stratum.