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文章主要阐述齐泰嫩江特大桥的概况、总体设计及设计要点;通过理论计算,分析了大跨度预应力混凝土连续梁桥顶板纵向开裂、腹板沿下束开裂、底版纵向裂缝产生的原因,提出在设计防止病害的措施。在设计中适当加强横向普通钢筋,并将横向束与纵向束同步张拉或先张拉横向束,加大横向预应力,以防止顶板纵向开裂,;适当加密底板横向筋,将后浇节段接缝处200cm范围内底板上、下缘所有横向筋间距采用8cm,其余采用12.5cm,以防止底版纵向裂缝;为防止腹板下弯束产生沿预应力钢束方向的裂缝,除采取可靠的施工工艺保证竖向预应力束的有效压应力外,尚需要对腹板的普通钢筋进行局部加强。
The article mainly introduces the general situation, overall design and design points of Qitai Nenjiang special bridge. By theoretical calculation, it analyzes the causes of the longitudinal crack of roof, the beam crack along bottom beam and the longitudinal crack of bottom plate of long-span prestressed concrete continuous beam bridge We devise measures to prevent disease. Appropriate to strengthen the design of horizontal ordinary steel, and the horizontal beam and longitudinal beam synchronization tension or pre-tensioning horizontal beam, increase lateral prestress, to prevent the longitudinal cracking of the roof; appropriate encryption of the floor transverse ribs, the after-pouring section Seams at 200cm within the scope of the bottom plate, the lower edge of all transverse rib spacing 8cm, the rest of the use of 12.5cm, to prevent longitudinal cracks in the bottom plate; Bending beam to prevent premature bending along the direction of prestressed tendons in addition to taking a reliable Construction technology to ensure the vertical prestressing beam effective compressive stress, but also the need for local reinforcement of ordinary steel web.