發(fā)布時間：2019-06-10 13:19

【摘要】：裝配式空心板梁橋具有施工速度快、造價低等優(yōu)點,是中國、美國、日本等國中小跨徑橋梁的主要橋型之一。隨著服役時間的增長,國內(nèi)空心板梁橋普遍出現(xiàn)鉸縫混凝土開裂的病害,導致橫向連接能力降低,最終造成單板受力的情況,威脅橋梁的結構和行車安全。針對存在單板受力病害的空心板梁橋,基于摩擦抗剪原理,本文提出了在梁高中心位置設置橫向預應力的加固方法,以恢復開裂混凝土鉸縫的剪力傳遞能力,進而改善空心板梁橋的橫向分布,達到加固目的。基于數(shù)值試驗,本文的主要研究內(nèi)容如下:首先,利用有限元軟件ANSYS建立空心板梁橋的有限元模型,以接觸單元模擬鉸縫混凝土的開裂面,計算分析荷載作用下橫向預應力、板間摩擦系數(shù)、板梁豎向撓度三者之間的相互關系。同時,給出空心板梁橋鉸縫在不同受壓高度時的橫向分布影響線,并與鉸接板法計算結果和鉸縫完好時的有限元計算結果進行對比分析。其次,以雙孔空心板梁為代表,詳細分析了橫向預應力作用下,接觸單元的應力分布規(guī)律,探討橋寬、橋長、預應力束數(shù)和大小、車輛荷載對鉸縫應力分布規(guī)律的影響。結果顯示,梁高方向,受空心板梁空腔和恒載作用影響,鉸縫壓應力主要分布于鉸縫頂部20 cm范圍內(nèi);橋長方向,相同鉸縫的受壓范圍基本不隨預應力的增大而變化。車輛荷載作用下,當預應力足夠時,開裂界面間相對滑移值趨于零,板梁處于共同受力狀態(tài)。最后,以我國13 m標準跨徑空心板梁橋為例,給出加固設計和計算過程。先分析預應力的有效作用范圍,結合橋梁跨度確定預應力布置方式,以車輛荷載作用下接觸單元的最大相對滑移值為控制目標,確定橫向預應力數(shù)值。并從加固后的空心板梁橋橫向分布和單點加載兩方面檢驗加固方案的可靠性,結果表明加固后的空心板梁橋橫向分布規(guī)律與鉸接板法計算結果吻合較好。
[Abstract]:The assembled hollow slab beam bridge has the advantages of fast construction speed and low cost. It is one of the main bridge types of small and medium-sized span bridges in China, the United States, Japan and other countries. With the increase of service time, the cracking disease of joint concrete generally occurs in hollow slab beam bridges in China, which leads to the decrease of transverse connection capacity, and finally leads to the stress of veneer, which threatens the structure and driving safety of bridges. Aiming at the hollow slab beam bridge with veneer stress disease, based on the friction shear principle, this paper puts forward a reinforcement method of setting transverse prestress at the center of beam height in order to restore the shear transfer capacity of cracked concrete joint. Then the transverse distribution of hollow slab beam bridge is improved to achieve the purpose of reinforcement. Based on numerical experiments, the main research contents of this paper are as follows: firstly, the finite element model of hollow slab beam bridge is established by using finite element software ANSYS, the crack surface of joint concrete is simulated by contact element, and the transverse prestress under load is calculated and analyzed. The relationship between friction coefficient between plates and vertical deflection of plates and beams. At the same time, the transverse distribution influence lines of hollow slab beam bridge joints at different compression heights are given, and the results are compared with those of the joint method and the finite element method when the joints are in good condition. Secondly, taking the double hole hollow slab beam as the representative, the stress distribution law of the contact element under the action of transverse prestress is analyzed in detail, and the influence of bridge width, bridge length, number and size of prestressed beam and vehicle load on the stress distribution law of the joint is discussed. The results show that the compressive stress of the joint is mainly distributed in the range of 20 cm at the top of the joint under the influence of cavity and dead load in the direction of beam height, and the compression range of the same joint does not change with the increase of prestress in the long direction of the bridge. Under the action of vehicle load, when the prestress is enough, the relative slip value between the cracking interfaces tends to zero, and the plate beam is in the common stress state. Finally, taking the 13 m standard span hollow slab beam bridge in China as an example, the reinforcement design and calculation process are given. Firstly, the effective action range of prestress is analyzed, and the prestress arrangement mode is determined according to the bridge span. The maximum relative slip value of contact element under vehicle load is taken as the control goal, and the transverse prestress value is determined. The reliability of the reinforcement scheme is tested from two aspects of transverse distribution and single point loading of the strengthened hollow slab beam bridge. The results show that the transverse distribution law of the strengthened hollow slab beam bridge is in good agreement with the calculation results of the bonded plate method.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：U445.72
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本文編號：2496480