高速鐵路預制拼裝箱梁橋抗彎及接縫抗剪試驗研究與理論分析
發(fā)布時間：2019-06-12 18:07
【摘要】：節(jié)段預制拼裝技術(shù)是將結(jié)構(gòu)整體分段預制后利用預應力技術(shù)再組裝為整體的手段,主要應用在大跨橋梁結(jié)構(gòu)中,具有預制標準、質(zhì)量可控、對施工機械要求低、施工工期短、受環(huán)境影響小等優(yōu)點,是橋梁結(jié)構(gòu)一個十分重要的施工技術(shù)。預制拼裝結(jié)構(gòu)與整體現(xiàn)澆結(jié)構(gòu)本質(zhì)的區(qū)別是普通鋼筋在接縫處不連續(xù),接縫處主要通過不同的形式進行拼接連接,極限狀態(tài)下結(jié)構(gòu)的受力性能有較大的差別,需要對其進行系統(tǒng)的研究�，F(xiàn)有的設計理論主要集中在幾個關(guān)鍵問題上：節(jié)段預制拼裝橋梁的抗裂性能,不同荷載階段下梁體的剛度,極限狀態(tài)下的抗彎承載能力,極限狀態(tài)下的抗剪破壞模式及其承載力�？箯澐矫姹疚幕趯�(jié)段預制拼裝梁與整體梁破壞本質(zhì)認識的基礎上建立了節(jié)段預制拼裝簡支梁及節(jié)段預制拼裝連續(xù)梁的體外預應力筋應力增量計算公式,并通過有限元模型對節(jié)段預制拼裝連續(xù)梁的內(nèi)力重分布進行了分析,建立了不同荷載階段下的抗彎剛度計算公式�？辜舴矫鎸捂I剪力鍵受剪破壞形式以及多鍵剪力鍵破壞形式進行了系統(tǒng)的分析,提出了相應的數(shù)值計算模型并進一步提出了簡化計算模型,對節(jié)段預制拼裝梁的抗剪破壞模式進行了探討并形成了抗剪承載力的計算公式。設計了10個剪力鍵抗剪試驗以及4根簡支梁、1根三跨連續(xù)梁進行試驗并對理論分析進行了驗證,本文的主要研究內(nèi)容及成果如下：(1)推導了節(jié)段預制拼裝橋梁受力全過程的剛度計算公式�；谡辰Y(jié)-滑移理論提出了接縫截面剛度影響范圍的概念,以節(jié)段為單位,按等效后轉(zhuǎn)角相同的方法推導了不同荷載等級下的節(jié)段預制拼裝梁等效剛度計算公式,其采用三折線形式-分為未開裂階段,正常使用階段,極限狀態(tài)階段,物理意義明確,結(jié)果精度高。(2)推導了節(jié)段預制拼裝梁體外預應力筋的極限應力增量的計算公式。討論了現(xiàn)有的簡支梁體外預應力筋應力增量的計算方法,基于等效塑性鉸理論,建立體外預應力整體簡支梁應力增量與極限位移的計算模型。提出了節(jié)段簡支梁與整體簡支梁極限位移的比例系數(shù)概念,推導了節(jié)段預制拼裝簡支梁極限位移的計算公式。根據(jù)梁體跨中位移與體外預應力筋應力成線性比例的關(guān)系,得到預制拼裝簡支梁體外預應力筋的極限應力增量計算公式,并形成了簡化計算公式。(3)提出了連續(xù)梁塑性鉸位置修正系數(shù)χ概念,基于等效塑性鉸理論推導了連續(xù)梁跨中極限位移的計算公式,并形成了體外預應力節(jié)段預制拼裝連續(xù)梁體外預應力筋極限應力增量的計算公式,通過試驗結(jié)果進行了驗證。采用纖維梁單元模型,考慮了節(jié)段梁截面剛度影響區(qū)域長度,建立了節(jié)段預制拼裝連續(xù)梁力學模型,并進行了內(nèi)力重分布影響因素分析,為節(jié)段預制拼裝連續(xù)梁的考慮內(nèi)力重分布的塑性設計提供了依據(jù)。(4)受彎方面進行了4個簡支梁(1個整體、3個節(jié)段)及1個三跨節(jié)段連續(xù)梁受彎試驗,根據(jù)試驗結(jié)果提出了節(jié)段預制拼裝梁抗裂分析的參數(shù)取值,并對建立的應力增量計算公式等進行了驗證。進行了10個不同接縫形式節(jié)段預制拼裝梁接縫抗剪試驗,考慮了水平壓力大小、干結(jié)與膠結(jié)、鍵齒大小、平接與鍵齒接縫等因素,對建立的簡化計算公式進行了驗證。(5)采用ABAQUS有限元軟件自帶混凝土CDP材料模型進行了初步分析,了解了剪力鍵抗剪破壞的機理,并與現(xiàn)有單鍵破壞試驗進行比對,給出了抗剪分析時CDP模型的參數(shù)設置建議。針對CDP模型的缺點,在分析剪力鍵受剪破壞原理的基礎上,開發(fā)了基于ABAQUS有限元軟件VUMAT子程序的混凝土抗剪模型,模型中體現(xiàn)了混凝土破壞準則、Ⅱ型斷裂能、剪斷后摩擦剪應力對剪力鍵受剪破壞的影響,通過已有剪力鍵受剪破壞試驗確定了混凝土抗剪模型參數(shù)取值,并驗證了模型的正確性,揭示了剪力鍵受剪破壞的原理。(6)利用開發(fā)的混凝土抗剪模型對剪力鍵受剪構(gòu)件進行了參數(shù)分析,考慮鍵齒形狀、水平壓力大小、鍵齒數(shù)目、接縫連接方式等因素對剪力鍵受剪承載力的影響,建立了接縫抗剪破壞承載力計算模型,形成了不同接縫形式接縫抗剪破壞承載力的計算公式,公式物理意義明確,形式參數(shù)統(tǒng)一,與試驗結(jié)果相比具有較高的精度。(7)在分析了節(jié)段預制拼裝梁與整體梁抗剪差異的基礎上,歸納了節(jié)段預制拼裝梁抗剪破壞的不同破壞形式及破壞機理。分析了不同接縫形式對混凝土部分抗剪承載力影響,根據(jù)混凝土的壓剪破壞準則,考慮了受壓翼緣對抗剪承載力的貢獻,編制了接縫抗剪破壞的計算分析程序,并采用簡化方式利用平衡方程對混凝土的抗剪承載力進行推導,形成接縫抗剪破壞的抗剪承載力計算公式,并進行了試驗數(shù)據(jù)的驗證。根據(jù)不同算例的試算結(jié)果給出了節(jié)段預制拼裝梁接縫抗剪破壞的產(chǎn)生條件,可用于橋梁的初期抗剪設計。
[Abstract]:The segment pre-assembly technology is a method for reassembling the whole structure of the structure by using the pre-stress technology, and is mainly applied to the large-span bridge structure, has the advantages of the prefabricated standard, the controllable quality, low requirements on the construction machinery, short construction period, small environmental impact and the like, It is a very important construction technology for bridge structure. The difference between the prefabricated assembly structure and the integral cast-in-place structure is that the common steel bar is not continuous at the joint, the joint is mainly spliced and connected in different forms, and the stress performance of the structure under the limit state is greatly different, and the system research is needed. The existing design theory is mainly focused on several key problems: the crack resistance performance of the segment pre-assembled bridge, the stiffness of the beam body at different load stages, the bending bearing capacity under the extreme state, the shear failure mode in the extreme state and the bearing capacity thereof. In the aspect of bending, this paper establishes the calculation formula of the stress increment of the in-vitro pre-stressed bar of the section pre-assembled simply-supported beam and the section pre-assembled continuous beam based on the understanding of the nature of the section-section pre-assembled beam and the whole beam's failure. The internal force redistribution of the continuous beam is analyzed by the finite element model, and the calculation formula of the bending stiffness at different load stages is established. The shear failure form of the single bond shear key and the damage form of the multi-key shear key are analyzed in the shear field. The corresponding numerical calculation model is proposed and the simplified calculation model is further put forward. The shear failure mode of the section precast assembly beam is discussed and the calculation formula of the shear bearing capacity is formed. Ten shear-key anti-shear tests and four simple and three-span continuous beams are tested and the theoretical analysis is verified. The main contents and results of this paper are as follows: (1) The formula for calculating the stiffness of the whole process of the segmental pre-assembled bridge is derived. Based on the theory of bond-slip, the concept of the influence range of the joint cross-section stiffness is put forward, and the equivalent stiffness calculation formula of the segment pre-assembled beam at different load levels is derived in the same way as the equivalent rear corner. The formula of the three-fold line-divided into the non-cracking stage, The normal operation stage, the limit state stage, the physical meaning is clear, and the result precision is high. (2) The calculation formula of the limit stress increment of the pre-stressed bar of the segmental pre-assembled beam is derived. In this paper, the calculation method of the stress increment of the in-vitro pre-stressed bar of simply-supported beam is discussed, and the calculation model of the stress increment and the limit displacement of the in-vitro pre-stressed integral simple-supported beam is established based on the equivalent plastic hinge theory. The concept of the ratio coefficient of the limit displacement of the simply-supported beam and the integral simple-supported beam is proposed, and the calculation formula of the limit displacement of the simple-supported beam is derived. According to the relationship between the displacement of the span of the beam body and the stress of the external prestressed tendon in a linear proportion, the formula for calculating the ultimate stress increment of the pre-assembled simple-supported beam external prestressed rib is obtained, and a simplified calculation formula is formed. (3) The concept of the position correction coefficient of the continuous beam plastic hinge is proposed, and the calculation formula of the limit displacement of the continuous beam span is derived based on the equivalent plastic hinge theory, and the formula for calculating the limit stress increment of the external prestressed tendon in the external prestressed section is formed. The results of the test were verified. In this paper, the section length of the section beam section is considered, the mechanical model of the section pre-assembled continuous beam is established, and the influence factor analysis of the internal force re-distribution is carried out, and the basis for considering the plastic design of the inner force redistribution of the section pre-assembled continuous beam is provided. (4) The bending test of four simple-supported beams (one whole, three sections) and one three-span section was carried out in the bending, and the parameter value of the crack-crack analysis of the segmental pre-assembled beam was put forward according to the test results, and the calculation formula of the stress increment was verified. In this paper, the shear test of the joint in 10 different joint-type segments is carried out. The simplified calculation formula is verified by considering the factors such as the horizontal pressure, the dry-knot and the cementation, the size of the key teeth, the flat-joint and the key-tooth joint. (5) The initial analysis of the concrete CDP material model with ABAQUS finite element software is carried out, the mechanism of shear-key anti-shear failure is understood, and compared with the existing single-bond failure test, the parameter setting suggestion of the CDP model is given. A concrete shear model based on the ABAQUS finite element software VUMAT subprogram is developed on the basis of analyzing the shear failure principle of the shear bond, and the effect of the shear stress on the shear failure of the shear bond is shown in the model. The parameter value of the shear model of the concrete is determined by the shear failure test of the existing shear key, and the correctness of the model is verified, and the principle of shear failure of the shear key is revealed. and (6) using the developed concrete shear model to perform the parameter analysis on the shear key subject to shear, taking into account the influence of the key tooth shape, the horizontal pressure size, the number of the key teeth, the joint connection mode and the like on the shear bearing capacity of the shear key, and establishing a calculation model of the shear failure bearing capacity of the joint, The calculation formula of the shear failure bearing capacity of the joint in different joint forms is formed, the formula is of clear physical meaning and the formal parameters are uniform, and the formula has higher precision compared with the test result. (7) On the basis of the analysis of the difference between the segmental pre-assembled beam and the overall beam, the different types of damage and the failure mechanism of the section pre-assembled beam's anti-shear failure are summarized. The influence of different joint forms on the shear bearing capacity of the concrete part is analyzed. According to the criterion of the compression and shear failure of the concrete, the contribution of the pressure flange to the shear bearing capacity is considered, and the calculation analysis program for the shear failure of the joint is developed. In this paper, the shear bearing capacity of the concrete is derived by using the equilibrium equation in a simplified way, and the calculation formula of the shear bearing capacity of the joint shear failure is formed, and the verification of the test data is carried out. According to the test results of different examples, the generation condition of the joint shear failure of the segment pre-assembled beam is given, and the initial shear design of the bridge can be used.
【學位授予單位】：東南大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：U446
，
本文編號：2498201
[Abstract]:The segment pre-assembly technology is a method for reassembling the whole structure of the structure by using the pre-stress technology, and is mainly applied to the large-span bridge structure, has the advantages of the prefabricated standard, the controllable quality, low requirements on the construction machinery, short construction period, small environmental impact and the like, It is a very important construction technology for bridge structure. The difference between the prefabricated assembly structure and the integral cast-in-place structure is that the common steel bar is not continuous at the joint, the joint is mainly spliced and connected in different forms, and the stress performance of the structure under the limit state is greatly different, and the system research is needed. The existing design theory is mainly focused on several key problems: the crack resistance performance of the segment pre-assembled bridge, the stiffness of the beam body at different load stages, the bending bearing capacity under the extreme state, the shear failure mode in the extreme state and the bearing capacity thereof. In the aspect of bending, this paper establishes the calculation formula of the stress increment of the in-vitro pre-stressed bar of the section pre-assembled simply-supported beam and the section pre-assembled continuous beam based on the understanding of the nature of the section-section pre-assembled beam and the whole beam's failure. The internal force redistribution of the continuous beam is analyzed by the finite element model, and the calculation formula of the bending stiffness at different load stages is established. The shear failure form of the single bond shear key and the damage form of the multi-key shear key are analyzed in the shear field. The corresponding numerical calculation model is proposed and the simplified calculation model is further put forward. The shear failure mode of the section precast assembly beam is discussed and the calculation formula of the shear bearing capacity is formed. Ten shear-key anti-shear tests and four simple and three-span continuous beams are tested and the theoretical analysis is verified. The main contents and results of this paper are as follows: (1) The formula for calculating the stiffness of the whole process of the segmental pre-assembled bridge is derived. Based on the theory of bond-slip, the concept of the influence range of the joint cross-section stiffness is put forward, and the equivalent stiffness calculation formula of the segment pre-assembled beam at different load levels is derived in the same way as the equivalent rear corner. The formula of the three-fold line-divided into the non-cracking stage, The normal operation stage, the limit state stage, the physical meaning is clear, and the result precision is high. (2) The calculation formula of the limit stress increment of the pre-stressed bar of the segmental pre-assembled beam is derived. In this paper, the calculation method of the stress increment of the in-vitro pre-stressed bar of simply-supported beam is discussed, and the calculation model of the stress increment and the limit displacement of the in-vitro pre-stressed integral simple-supported beam is established based on the equivalent plastic hinge theory. The concept of the ratio coefficient of the limit displacement of the simply-supported beam and the integral simple-supported beam is proposed, and the calculation formula of the limit displacement of the simple-supported beam is derived. According to the relationship between the displacement of the span of the beam body and the stress of the external prestressed tendon in a linear proportion, the formula for calculating the ultimate stress increment of the pre-assembled simple-supported beam external prestressed rib is obtained, and a simplified calculation formula is formed. (3) The concept of the position correction coefficient of the continuous beam plastic hinge is proposed, and the calculation formula of the limit displacement of the continuous beam span is derived based on the equivalent plastic hinge theory, and the formula for calculating the limit stress increment of the external prestressed tendon in the external prestressed section is formed. The results of the test were verified. In this paper, the section length of the section beam section is considered, the mechanical model of the section pre-assembled continuous beam is established, and the influence factor analysis of the internal force re-distribution is carried out, and the basis for considering the plastic design of the inner force redistribution of the section pre-assembled continuous beam is provided. (4) The bending test of four simple-supported beams (one whole, three sections) and one three-span section was carried out in the bending, and the parameter value of the crack-crack analysis of the segmental pre-assembled beam was put forward according to the test results, and the calculation formula of the stress increment was verified. In this paper, the shear test of the joint in 10 different joint-type segments is carried out. The simplified calculation formula is verified by considering the factors such as the horizontal pressure, the dry-knot and the cementation, the size of the key teeth, the flat-joint and the key-tooth joint. (5) The initial analysis of the concrete CDP material model with ABAQUS finite element software is carried out, the mechanism of shear-key anti-shear failure is understood, and compared with the existing single-bond failure test, the parameter setting suggestion of the CDP model is given. A concrete shear model based on the ABAQUS finite element software VUMAT subprogram is developed on the basis of analyzing the shear failure principle of the shear bond, and the effect of the shear stress on the shear failure of the shear bond is shown in the model. The parameter value of the shear model of the concrete is determined by the shear failure test of the existing shear key, and the correctness of the model is verified, and the principle of shear failure of the shear key is revealed. and (6) using the developed concrete shear model to perform the parameter analysis on the shear key subject to shear, taking into account the influence of the key tooth shape, the horizontal pressure size, the number of the key teeth, the joint connection mode and the like on the shear bearing capacity of the shear key, and establishing a calculation model of the shear failure bearing capacity of the joint, The calculation formula of the shear failure bearing capacity of the joint in different joint forms is formed, the formula is of clear physical meaning and the formal parameters are uniform, and the formula has higher precision compared with the test result. (7) On the basis of the analysis of the difference between the segmental pre-assembled beam and the overall beam, the different types of damage and the failure mechanism of the section pre-assembled beam's anti-shear failure are summarized. The influence of different joint forms on the shear bearing capacity of the concrete part is analyzed. According to the criterion of the compression and shear failure of the concrete, the contribution of the pressure flange to the shear bearing capacity is considered, and the calculation analysis program for the shear failure of the joint is developed. In this paper, the shear bearing capacity of the concrete is derived by using the equilibrium equation in a simplified way, and the calculation formula of the shear bearing capacity of the joint shear failure is formed, and the verification of the test data is carried out. According to the test results of different examples, the generation condition of the joint shear failure of the segment pre-assembled beam is given, and the initial shear design of the bridge can be used.
【學位授予單位】：東南大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：U446
，
本文編號：2498201
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