Study On Static-dynamic Characteristics And Construction Technology For The Inclined Large Cantilevered Concrete Beam With Variable Cross-section

The inclined large cantilevered concrete beams with variable cross-section arewidely used to meet the demands for engineering applications, which promotes thecontinuous development of theoretical research and construction technology in thefield. The cantilevered grandstand for some school library lecture hall was taken asresearch subject, and the study on static-dynamic characteristic and constructiontechnology was carried out by theoretical analysis in combination with numericalsimulation and engineering verification, which not only can meet the engineeringdemands, but also accumulate the research results.The research results are summarized as follows:1. By using the theoretical analysis the simplified diagram was put forwardaccording to the mechanical characteristics of the inclined beam with variablecross-sections; and the equations for determining the location with maximumnormal stress and maximum shear stress was derived; and the method waselaborated to find out the most dangerous location in combination with the actualengineering cases; and the normal section bearing capacity, inclined section bearingcapacity, maximum crack width and deflection for the large cantilevered concretebeam with variable cross-section was calculated; in addition finite element analysiswas carried out to verify the numerical simulation results with theoretical results,and the sensitivity analysis of the density, the concrete strength and otherparameters on the static performance was carried on.2. Modal analysis of the actual cantilevered grandstand was carried out to findout its vibration characteristics; And combined with the characteristics of its loadstatus, the dynamic response of the inclined large cantilevered concrete beam withvariable cross-section was analyzed when subjected different human-inducedvibration cases, such as rose load, slow walking load, jumping load; In addition thetime history analysis when the beam is subjected to vertical seismic load was putforward to prove that it satisfies the requirement of seismic design.3. The construction technology was elaborated from the aspects of the template works, steel works and concrete works; Based on an engineeringbackground, the study on the case for removing temporary support for the inclinedcantilevered beams was carried out, and the universal uninstall principle wasproposed; The integrated utilization of testing data and model updating technologynot only can quantitatively evaluate the construction results, but also provide apreliminary technical approach for afterwards evaluation.