Project Overview

At present, the Jiangnan Ancient City project is under construction in the first and second phases of the Ming and Qing dynasties, with a construction area of approximately 290,000 square meters, of which approximately 150,000 square meters are residential and 140,000 square meters are commercial. The first phase has entered the delivery phase, and the second phase is undergoing indoor and outdoor decoration works.

In the construction of the first phase of the Ming and Qing Dynasties project in the ancient city of Jiangnan, due to the adjustment of the overall planning of the project and the guarantee of fire protection and completion acceptance, the original building business needs to be changed and designed. The first floor of some shops is opened, and the indoor reinforced concrete stairs from the first floor to the second floor are added. In addition, in order to ensure the bearing capacity and bearing performance of the original structure and meet the safety and durability of the structure, the original structural beams and slab members need to be reinforced at the location where the floor slab is opened.

Opening of floor slabs and reinforcement of beams and slabs

Structural reinforcement design

The built buildings in the Jiangnan Ancient City project that involve opening and strengthening of slabs and the addition of stairs are five-storey commercial and residential buildings (2 + 3), the bottom two floors are shops, and the upper part is three-story residences (taking 39 # building as an example). The structural form of Building 39 # is a cast-in-situ concrete frame structure. The building seismic fortification category is Class C, the seismic fortification intensity is 6 degrees 0.05g, and the safety level is Class II; the frame seismic class is Class IV; and the foundation design level is Class C.

According to the construction situation of the project, the reinforcement of the frame beam, primary and secondary beams, frame columns and slabs at the opening of the floor slab, the cross-sectional size, the concrete strength level and other parameters should be reviewed with the original structure construction drawing. Determine whether to carry out construction according to the original structural design and construction drawings to provide basic information for reinforcement design.

In order to ensure the bearing capacity of the original structure, after the opening of the floor slab, reinforcement treatment is required at the opening location. The reinforcement design scheme is to add cantilever beams on the primary and secondary beams of the original structure through the reinforcement planting process, and the ladder beam of the newly added staircase is also connected to the frame column using the reinforcement planting process.

Construction Technology

The main construction technology of this project includes the chiseling of floor slab concrete, the process of planting reinforcement and the pouring of newly added reinforced beams.

1 slab opening

Open the floor slab to increase the staircase line

Floor concrete picking construction

2 post installed reinforced bar

3 new reinforcement beams

Chisel grouting hole

Reinforcement of reinforced beams

Project summary

The opening of the floor slab in the Jiangnan Ancient City project is a professional reinforcement project. The construction process met the design specifications and the bearing capacity requirements of the structural design through the test of the pull-out strength of the rebar and the compressive strength test of the test block. The perfect combination of the reinforcement design scheme and the building function will ensure the acceptance of the project and the progress of the project.