| Due to the excellent structural properties of concrete continuous rigid frame bridge, it becomes the First choice option for long span bridge. However, during the construction and operation, continuous rigid frame bridge will have a variety of different forms of cracks, the cracking of midspan baseplate become a prominent problem hinder, also become a problem which common attention by engineering and academia. Baseplate cracks make very adverse effects to structure safety and durability, so the analysis of Cracks Cause in baseplate and its mechanics behavior for Continuous Rigid Frame Bridge, it Has a high engineering significance.This paper on the basis of existing crack analysis theory, summarizes the constitutive relation and failure criteria of concrete materials. Contrary to cracking characteristics of the structure, introduced nonlinear analysis method of this paper, and introduces the Finite element model about treatment and choice of element.Summarizes cracking reasons and destroying forms of baseplate from design and construction, and summarizes the influence factors of the collapsed force from Box girder baseplate linear, baseplate broken line linear, baseplate cover thickness and so on, reach a conclusion that the main reason of baseplate cracking is Radial force caused by tension prestressing tendons, and the radial force of actual construction process is greater than design value. Draw the suggest formula for baseplate cover thickness and center critical distance of bellows.Simulate the influence factors of baseplate cracking by computer, summarizes the reason of baseplate cracking. Though the simulation of different baseplate thickness, different tension order, prestressing tendons chipping off in different place and Poisson effect, Put forward the design and construction suggestions of thickening baseplate cover and prestress tension method, and make a assessment about influence degree of these effect by computer.Finally based on preventing baseplate cracking key point of continuous rigid frame bridge, lists commonly used method of preventing baseplate cracking From the aspect of design and construction, And introduces the characteristics of various processing method. |
