为解决单线铁路隧道施工过程中遭遇的高地应力软岩大变形进而导致的初期支护破坏问题，对原直板形限阻器进行优化，研究其在不同优化参数下的力学性能，并将其应用于中老铁路沙嫩山二号隧道单线段，开展限阻耗能型初期支护现场试验。通过限阻器性能参数试验研究和施工应用效果研究，得出以下结论： 1）弧板限阻器受压变形时方向可控，有效行程得以提高，经历弹性变形、屈服下降变形、恒阻塑性变形和压实上升4个阶段。2）改变限阻器竖向钢板径高比可以改变限阻器的初始应力峰值，但对恒阻应力值的影响很小，实际应用限阻器时应选取对应初始应力峰值为8 MPa时的径高比较为合适。3）试验段采用限阻器后，围岩压力得到释放，避免了初期支护过载破坏，在未加强初期支护参数的前提下，既保证了支护结构的安全性，又提高了经济性。
The primary support of singletrack
railway tunnels can be damaged owing to large deformations in soft rocks caused
by high geostress. An optimization strategy for the original straightplatetype supportresistant
limiting damper(SRLD) is presented and the mechanical properties of the
optimized SRLD under different optimization parameters are examined. To conduct
field tests on a restricted energydissipationtype primary support, the SRLD is applied to the singletrack section of the Shanenshan No. 2 tunnel of ChinaLaos railway. The results of the parameter test and the application
of the SRLD are analyzed as follows. (1) The direction of the curvedplate SRLD is controllable when the plate is compressed and
deformed, and the SRLD undergoes four stages: elastic deformation, yielddecline deformation, constantresistance
deformation, and compaction rise. (2) Changing the diametertoheight ratio of the vertical connecting
steel plate of the SRLD can change the initial peakpressure
value of the SRLD, affecting the constantresistance
value marginally. Therefore, in practice, the diametertoheight ratio of the vertical connecting steel plate of the SRLD must
be selected according to the initial peak value of 8 MPa. (3) After the SRLD is
used in the test section, the surrounding rock pressure is released to protect
the primary support structure from invasion and limit damage. Moreover, the
construction safety and economy can be guaranteed under the condition that
support parameters are not strengthened.
