复合拱圈加固圬工拱桥模型试验及工程应用研究

发布时间：2019-06-24 22:01

【摘要】：圬工拱桥采用复合拱圈加固后，能够提高加固结构的整体性、耐久性、强度、刚度和承载力，同时，这种加固方法因其施工方便、造价低廉等优点，在我国应用前景广阔。但是，就圬工拱桥加固理论而言，国内外就此开展的理论研究很少。因此研究复合拱圈加固圬工拱桥的加固技术，具有十分重要的理论意义和实际工程应用价值。本文以某实施复合拱圈技术加固的圬工拱桥为工程背景，采用理论分析、数值模拟及模型试验相结合的方法，研究了加固后的拱段。针对加固拱段的受力特点，系统研究了理论分析方法、承载能力、破坏形态、应力-应变曲线、复合拱圈统一偏心受压本构关系和加固后正截面极限承载力计算方法。最后，将所研究的主要内容应用于复合拱圈加固石拱桥的设计示例中，促进了研究成果在工程实践中的应用。主要研究成果如下： 1、设计制作了9个典型的加固柱和2个未加固的对比柱，并进行阶段试验设计。制定完整试验计划，明确测试内容和试验目的，确定受压破坏的静力试验加载方案。上述工作是加固试验完成的前提条件，直接关系到整个试验的成败，为复合拱圈加固圬工拱桥提供分析基础和计算依据。 2、在试验室2000kN千斤顶上进行了11个模型的试验，加载过程中，观察各试件的破坏过程，采集了各试件的承载力、荷载-应变曲线。对影响试件极限承载力的各种因素，包括受压区高度、原拱圈裂缝高度、加固层宽度和初应力一一作了分析。发现各试件在测试截面处的荷载-应变曲线的整体测试值与局部测试值基本接近，验证了试验数据的准确性。通过对试验数据分析，加载初期时砌体和混凝土复合拱圈截面应变分布情况不满足平截面假定，随着荷载的不断增大，复合拱圈截面应力重分布，砌体和混凝土层协调变形、共同受力，加载至0.9Pu时截面应变分布仍近似满足平截面假定。因此可近似认为复合拱圈截面的变形满足平截面假定。 3、根据复合拱圈满足平截面假定的条件，基于4种常用的不同混凝土本构关系和1种常用的砌体本构关系，分别推导了4种复合材料的本构关系。将这4种复合材料本构关系应用于试件的有限元仿真模型中，比较有限元数值和实测数值，结果表明，采用混凝土Rüsch二次抛物线加水平直线模式推导出的复合材料本构关系的极限承载力有限元数值接近实测数值。以该复合材料本构关系模型为研究对象，分析应力-应变云图：发现理论破坏过程与实际破坏过程相近；对比理论荷载-应变数值和曲线与实际荷载-应变数值和曲线的，可以看出，砌体和混凝土偏压构件的荷载-应变曲线理论值和实际值能较好地吻合。说明混凝土采用Rüsch二次抛物线加水平直线模式推导出的复合材料本构关系还是比较符合实际情况的。从而，为复合拱圈加固圬工拱桥数值分析提供了准确的简化方法。 4、考虑加固前原拱圈的初应力，砌体、混凝土和钢筋的本构关系，针对加固前圬工主拱圈是否出现横向裂缝，以混凝土肋式截面加固圬工拱桥为例，推导了复合拱圈加固圬工拱桥的正截面极限承载力计算公式。采用适于工程师使用的mapple软件，可以快速计算所求截面极限承载力。算例表明，公式计算值与试验实测值相比，误差在9%以内，为该推导公式在工程实际应用中提供可靠的理论支撑，说明本文所推导的公式还是比较符合工程实际应用。因为推导的公式对于大、小偏心受压构件均适合，所以该公式具有较高的适用性。 5、基于平截面假定，复合材料本构关系和推导的复合拱圈加固圬工拱桥极限承载力公式，详细提出从截面设计到截面复核的加固设计流程。通过一个较为全面的复合拱圈加固圬工拱桥的设计示例，证明了本文推导的复合材料本构关系和极限承载力计算公式可以安全可靠的应用于复合拱圈加固圬工拱桥的正截面极限承载力计算中，把理论分析和工程实践完整的结合起来，促进了研究成果更好的推广应用于工程实践。综上所述，，文中具有的创新点为： 1、基于试验数据分析，验证了加固截面加载至破坏的平截面假定。加载初期由于砌体和混凝土的变形不同步，所以截面应变分布情况并不满足平截面假定。随着加载的不断增大，组合截面应力重分布，砌体和混凝土层协调变形、共同受力，加载至0.9Pu时截面应变分布近似满足平截面假定，因此可近似认为复合截面的变形满足平截面假定。 2、根据复合拱圈满足平截面的假定条件，基于4种常用的不同混凝土本构关系和1种常用的砌体本构关系，分别推导了4种复合材料的本构关系。将这4种复合材料本构关系应用于试件的有限元仿真模型中，通过有限元数值与相应的模型试验实测数值的对比，分析得出混凝土采用Rüsch二次抛物线加水平直线模式的复合材料本构关系计算的承载力与实际试验值接近。将该复合材料的本构关系应用于工程实例的有限元分析中，在精简有限元模型和简化计算工作量同时，仍能准确地计算极限承载力。 3、基于加固结构初应力和加固材料非线性，针对加固前圬工主拱圈是否出现横向裂缝，推导出的正截面极限承载力公式，并用试验进行验证。结果表明，公式计算值与试验实测值误差在9%以内，可以准确快速计算各截面极限承载力。再将该极限承载力公式应用于工程实例中，公式计算值与有限元计算值相近，说明推导公式能安全可靠应用于工程实践中。
[Abstract]:After the arch bridge is reinforced by the composite arch ring, the integrity, the durability, the strength, the rigidity and the bearing capacity of the reinforcing structure can be improved, and at the same time, the reinforcing method has the advantages of convenient construction, low manufacturing cost and the like, and has wide application prospect in China. However, in the case of the reinforcement theory of the arch bridge, there is little research on the theoretical research carried out at home and abroad. Therefore, it is of great theoretical significance and practical engineering application value to study the reinforcement technology of composite arch ring for strengthening the arch bridge. In this paper, by means of the combination of the theoretical analysis, the numerical simulation and the model test, the reinforced arch bridge arch bridge is used as the engineering background, and the arch-reinforced arch bridge is studied. In this paper, the theoretical analysis method, the bearing capacity, the damage form, the stress-strain curve, the unified eccentric compression constitutive relation of the composite arch ring and the calculation formula of the ultimate bearing capacity of the positive section after the reinforcement are studied for the stress characteristics of the reinforced arch section. Finally, the main content of the research is applied to the design example of the composite arch-ring reinforced stone arch bridge, and the research results are promoted in the engineering practice. The main research results are as follows: Next:1,9 typical reinforcement columns and 2 unreinforced contrasting columns were designed and staged Inspection and design. Establish complete test plan, specify test content and test objective, and determine static test of pressure failure. The above-mentioned work is a prerequisite for the completion of the reinforcement test, which is directly related to the success or failure of the whole test, and provides an analysis foundation and a meter for the composite arch ring to reinforce the arch bridge Based on.2, the test and loading of 11 models on the 2000kN jack in the laboratory are carried out, and the damage process of each test piece is observed, and the bearing capacity and the load of each test piece are collected. -strain curve. Various factors that affect the ultimate bearing capacity of the test piece, including the height of the compression area, the height of the original arch ring, the width of the reinforcement layer and the initial stress. An analysis was made. The overall test value of the load-strain curve at the test section of each test piece was found to be close to the local test value and the number of tests was verified According to the test data analysis, the stress redistribution of the composite arch ring and the coordination and deformation of the masonry and the concrete layer are not satisfied by the analysis of the test data and the distribution of the section strain of the composite arch ring of the masonry and the concrete at the beginning of the loading. And the strain distribution of the cross-section is still nearly satisfied when the load is loaded to 0.9 Pu. The assumption of the flat section is that the deformation of the section of the composite arch ring can be considered to be satisfied. 3. According to the condition that the composite arch ring meets the assumption of the flat section, four kinds of composite concrete constitutive relation and one kind of common masonry constitutive relation are derived based on four commonly used constitutive relations of different concrete and one commonly used masonry constitutive relation. The constitutive relation of the material is applied to the finite element simulation model of the test piece, and the finite element value and the actual measurement are compared. The numerical results show that the finite element number of the ultimate bearing capacity of the composite material constitutive relation is derived by the secondary parabolic and horizontal linear mode of the concrete R-sch. The value is close to the measured value. The constitutive relation model of the composite material is the study object, and the stress-strain cloud picture is analyzed. The theoretical damage process is found to be similar to the actual failure process, and the theoretical load-strain value and the curve and the actual load-strain value and the curve are compared. As can be seen from the line, the theoretical and practical values of the load-strain curves of the masonry and concrete-biased components The results show that the constitutive relation of the composite material derived from the R-Ssch-quadratic parabola and the horizontal straight-line mode is a good agreement. According to the actual situation, the numerical analysis of the arch bridge reinforced by the composite arch ring is provided. 4. Considering the constitutive relation of the initial stress, the masonry, the concrete and the steel bar of the original arch ring before the reinforcement, whether the transverse crack is present in the main arch ring of the front arch ring before the reinforcement, and the concrete ribbed section In this paper, the positive cross section of the arch bridge reinforced by the composite arch ring is derived for example. Calculation formula for ultimate bearing capacity. The ultimate bearing capacity of the section is obtained. The example shows that the error is within 9% of the calculated value of the formula, which provides a reliable theoretical support in the practical application of the engineering, and the formula or the ratio derived in this paper is explained. The proposed formula is suitable for large and small eccentric compression members, so the utility model The formula has high applicability.5. Based on the assumption of the flat section, the constitutive relation of the composite material and the formula of the ultimate bearing capacity of the composite arch ring reinforced by the composite arch ring, the design of the section from the section is proposed in detail. In this paper, the design example of a comprehensive composite arch ring for strengthening the arch bridge is proved, and the constitutive relation and ultimate bearing capacity of the composite arch bridge are proved to be safe and reliable. In the calculation of the ultimate bearing capacity of the positive section, the combination of the theory analysis and the engineering practice is integrated, and the research results are promoted. Good application in engineering practice. As stated above, the point of innovation in this paper is:1. Based on the data analysis of the test, it is verified The reinforced section is loaded into the flattened section of the failure. The section of the section is not synchronized due to the deformation of the masonry and the concrete at the beginning of the load, so the section The distribution of the strain is not satisfied with the assumption of the flat section. With the increasing loading, the stress redistribution of the combined section, the coordination and deformation of the masonry and the concrete layer, the joint force and the strain distribution of the section at the time of loading to 0.9Pu meet the assumption of the flat section, so it can be considered as an approximation. For the deformation of the composite section, the assumption of the flat section is satisfied.2. According to the assumption that the composite arch ring meets the flat section, the constitutive relation of four common types of concrete and the constitutive relation of one kind of common masonry are based on four kinds of common different concrete constitutive relation. In this paper, the constitutive relation of four composite materials is derived respectively. The constitutive relation of the four composites is applied to the finite element simulation model of the test piece, and the constitutive relation of the four composites is obtained by the finite element method. Based on the comparison between the numerical value and the corresponding model test, the composite material of the R-sch secondary parabola and the horizontal linear mode is obtained. The bearing capacity of the structural relationship is close to the actual test value. The constitutive relation of the composite material is applied to the finite element analysis of the engineering case, and the finite element model and the simplified calculation are simplified. At the same time, the ultimate bearing capacity can be calculated accurately.3. Based on the initial stress of the reinforcement structure and the non-linearity of the reinforcement material, the transverse crack appears in the main arch ring of the pre-reinforcement for reinforcement, and the result is derived. The formula of the ultimate bearing capacity of the positive section is calculated and verified with the test. The result shows that the error of the formula calculation value and the test measured value is 9%. the ultimate bearing capacity of each section can be accurately and quickly calculated, and the ultimate bearing capacity formula is applied to the engineering example, and the formula calculation value is similar to that of the finite element calculation value,
【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U448.22

【参考文献】