Bridge expansion joints Specifications Model Price manufacturer

As an example, model and parameter take a 30m Span Hollow Slab mainly calculated lateral force of the hollow plate, especially in parts of the lateral force of the base plate. Analysis calculated according to the model of the plane stress unit uses an 8-node isoparametric element. Longitudinal access airbags conservative force length along the bridge length L 70cm. 30m span hollow Itabashi calculated load: Liang weight is 43t two dead loads 9t. The results calculated by the finite element bearing replacement in the construction process, the beam suffered the maximum shear stress 1.03 MPa. The maximum principal tensile stress of beam 5. 3.33MPa, larger than normal c40 concrete under the stage load combinations II the allowable principal tensile stress [d: -] a 2.34MPd; principal tensile stress [shad] 3.38MPa very close to c40 concrete flexural components allow construction phase . But taking into account the range of larger principal tensile stress, and calculated using the more conservative vertical bridge to only 70cm beam is assumed to participate in the force, so the lifting process, the basic principal tensile stress in the beam in the safe range . Beam maximum principal stress S. : == 2.73MPa, far less than the normal stage c40 concrete allowable principal compressive stress of 18.2MPa. Therefore, main beam compressive stress to meet code requirements. To solve this problem, the company is based on many years of experience in the construction of prestressed, according to the company's existing technology advantage, successfully developed a separate controllable from the top of the system to ensure uninterrupted traffic of the bridge under normal operations, not to destroy bridge structure deck continuous system) time (do not destroy the unilateral breaking traffic safety, quick replacement of damaged bearings. The system can be divided into separate hydraulic controlled automatic top and pneumatic systems separate controllable automatic from the top of the system. Air Jack is a new development in recent years, a jacking equipment, bridge jacking process the main configuration: airbag cushion, high pressure hose, pressure shunt, high pressure pump, control systems, and electronic monitoring. Air Jack is made from high quality rubber wire material, the relevant technical indicators: design maximum stress 1.6MPa withstand maximum load 40t; airbag geometry: length 70cm, width 58cm, thickness 3cm. Other jacks are unable to meet the needs of small construction space requirements, due to the smaller size of the structure, especially the thickness of ultra-thin, "ultra-low profile balloon jack can be directly in the cap beam from the top to fit in the hollow plate Liang jacking and jacking gap smaller objects. "Ultra-low-high inflatable jack" not only in the structure size to meet the requirements directly on top of the cap beam and lifting small gap, and full compliance with the relevant requirements of the construction from the top of the stress analysis. In order to ensure the smooth progress of the construction job, be aware of the hollow plate stress, deformation analysis, and mechanics, focusing understand the structure of the force after internal changes.