为解决传统工字钢+喷射混凝土临时仰拱施工工序复杂、施作质量受人为因素影响大、无法循环利用的难题，依托实际工程，提出一种新型可拆构件式钢管混凝土临时仰拱及其配套快拆结构，并在同塞高速总卡2#隧道开展测试应用。临时仰拱钢管外径108 mm，壁厚8 mm，管内填充C30细石混凝土；
快拆结构由套筒和内置楔形卸荷块组成，钢管混凝土从两侧插入，实现节段连接。现场应用结果表明： 1）该可拆构件式钢管混凝土临时仰拱结构安全可靠、工艺可行，可实现工厂预制加工及现场快速拆装，较传统工字钢+喷射混凝土临时仰拱工效提高64.3%，拱顶沉降变形速率降低65.7%~66.1%，周边收敛速率降低74.6%~79.5%； 2）结构运行期间实测轴力值小于计算值和设计值，结构处于安全状态，节段重复利用率达94.5%，快拆结构重复利用率达100%。
The traditional temporary invert constructed by Isteel
+ shotcrete is complex in the construction process. Moreover, its construction
quality is greatly affected by human factors and cannot be reused. Therefore, a
novel detachable concretefilled steel tube temporary
invert and its supporting structure, designed for easy and rapid disassembly,
are proposed. The structures are tested and applied to the highspeed Zongka #2 tunnel of the TongrenSai′erlong railway. The steel pipe has an outer
diameter of 108 mm and a wall thickness of 8 mm, and is filled with C30 fine
stone concrete. The detachable components comprise a sleeve and a builtin wedgeshaped unloading block, and the concretefilled steel tubes are inserted from both sides to achieve segment
connection. Field application results reveal the following: (1) The proposed
temporary invert structure is safe, reliable, and feasible and can realize
factory prefabrication and quick disassembly on site. The proposed temporary
invert can improve construction efficiency by 643% and
reduce the settlement deformation rate of the arch and peripheral convergence
rate by 657%~661% and 746%~795%, respectively, compared to the
traditional temporary invert constructed by I-steel + shotcrete. (2) The axial
force value measured during the operation of the structure is less than the
calculated and designed ones, indicating that the structure is in a safe state.
The reutilization rates of the segment and detachable structure are up to 94.5%
and 100%, respectively.
