无粘结预应力混凝土平板开洞技术（Opening technology of unbonded prestressed concrete slabs）.doc

无粘结预应力混凝土平板开洞技术（Opening technology of unbonded prestressed concrete slabs） [Abstract] because of the high requirement, the Linghai L and 2 story hall two-way unbonded prestressed concrete roof is completely removed along the sides of the surrounding beam, and the opening is 8m * 7.45m, because of the high requirement of the use of the Beijing industrial and agricultural products exhibition hall. In this paper, the method of opening is expounded in detail from the setting up of slab bottom support system, the elimination of concrete slab, the cutting and releasing of prestressing tendon, the reinforcement of Zhang La end surface and re stretching. Keywords opening project; unbonded prestressed concrete slab; removal of prestressing tendon; reinforcement; Industrial and agricultural products of Beijing city new Fengtai District Linghai agribusiness joint company showroom project has a total construction area of 2 44561.87m, divided into A, B two. The A building area of 40124.87m2, underground l layer, the ground layer 3, the standard storey is 4.2m floor with unbonded prestressed concrete flat beam and plate structure, with the size of 9000mm * 9900mm, 9900mm * 9900mm, Liang Kuan 1000, 1200mm flat two, high of 500mm, thickness of 200mm plate unbonded prestressed steel strand for two-way curve layout. 1 openings Engineering Overview The main structure of this project, unbonded prestressed concrete flat beam and slab construction, was completed in 1998, l and February. L in early 999, the construction unit in the approval of the view that the entrance height is too low, so the requirements will be 1, 2, 1 / A - B, l, 2, a L 3 axis between the unbonded prestressed concrete roof removal. That is to be in the 9000mm * 8100mm column in 3, along the road of unbonded prestressed concrete flat beam and 1 non prestressed concrete edge beam edge of unbonded prestressed concrete flat roof will be deleted, and related parts of the recovery and elimination of prestress, the size of