The capping beam construction support adopts steel bars embedded in the pier body, and the capping beam support is erected by using the embedded steel bars. At the top of pier column, reinforcing bar installation holes are embedded along the radial direction of pier shaft perpendicular to the axis of capping beam, and the buried depth is 1.33m (to the bottom of PVC pipe). The reserved hole is made of PVC material, and the inner diameter of the pipe is 160 mm. Before the formwork installation, the nozzle is blocked to prevent concrete from pouring into the pipe. The bearing support adopts steel bars with the diameter of 140mm, steel wedges are supported on the steel bars to adjust the height of the system, and HM588 steel is erected on the steel wedges as the longitudinal beam of the support system. Set φ 18 bolt holes on HM588 longitudinal beam and fix them with steel wedge. I 16 I-beams are horizontally erected on longitudinal beams every 500mm as distribution beams, and 1.0m is set aside at both ends of the distribution beams as construction operation platforms. The platform is paved with 3cm boards, with railings and protective nets around the platform. The height of the protective net is1.2m. ..
Working principle:
The construction of unsupported capping beam and integral installation of steel bars is a construction method of setting reserved holes on the pier and installing steel bars to transfer the force to the pier. The integral installation of steel bars is to tie and shape the capping beam steel bars in the steel yard in advance and install them by crane, which reduces the overhead working time, improves the construction efficiency and reduces the safety risk.
Ideas:
The foundation must be treated first in the construction of capping beam support method. Juhuawan Bridge has 28 capping beams, and each capping beam needs foundation treatment, which has high cost, high capping beam height and large scaffold investment. However, the construction of core-piercing steel bar mainly uses the bearing capacity of pier to support the weight of top-capped formwork, which effectively solves the cost of foundation treatment and support investment.
On-site binding of capping beam reinforcement takes a long time, and all of them work at high altitude, which has great safety risks. However, the capping beam steel bars are integrally hoisted in place after binding and molding in the steel yard, which greatly shortens the overhead working time, reduces the safety risk and improves the construction efficiency.