Research On Design Method Of Frame-supported Shear Wall Structure Considering P-Δ Effect

As a widely used high-rise building structure,the second-order effect of frame-supported shear wall structure can not be ignored.How to reasonably consider the second-order effect of structure is an important issue in structural design.In recent years,scholars in various countries have made many achievements in the research of second-order effect,but due to the complexity of second-order effect and the structural particularity of frame-supported shear wall,the simplified calculation method of second-order effect of frame-supported shear wall structure which can be applied to engineering needs further analysis and verification.Therefore,on the basis of analyzing the lateral deformation law of structure and considering material and geometric nonlinearity,a simplified calculation method of second-order effect oriented to engineering practice is proposed,which will be of great significance to engineering analysis and structural design.The simplified calculation method for second-order effect of frame-supported shear wall structure is not clearly stated in the current code.If the simplified calculation method in the code is applied to analyze,the rationality of this method needs to be verified.Therefore,this paper will verify the applicability of simplified calculation method and corresponding stiffness reduction coefficient in frame-supported shear wall structure based on the calculation method of second-order effect in current code for Design of Concrete Structures(GB50010-2010)and Technical code for Concrete Structures of High-rise Buildings(JGJ3-2010),and suggestions on the application scope of simplified calculation method and the value of related stiffness reduction coefficient are put forward.On this basis,this paper has achieved the following research results:(1)Through a specific example,the lateral deformation of the structure is screened and compared,which further illustrates the lateral deformation characteristics of the frame-supported shear wall structure.That is,the structure is bounded by the transfer story,the lower frame structure shows obvious shear deformation,and the upper shear wall structure shows obvious bending deformation.With the increase of the number of transfer stories,the lateral deformation law of the structure has no obvious change.(2)The applicability of the simplified calculation method in the current code is verified and judged,and the applicable scope of the method is put forward as follows: the effective envelope of the actual internal force and displacement increment coefficients can be achieved by using Overall Increase Coefficient Method in the whole height range of the structure,but the calculation accuracy is not high and the results are too safe;The Overall Increase Coefficient Method and the Layer Increase Coefficient Method are used in the height range of the upper shear wall structure of the transfer story.For displacement analysis,the Overall Increase Coefficient Method can meet the requirements,while the layer increase coefficient method is no longer suitable for displacement calculation.For internal force analysis,the calculation results of Overall Increase Coefficient Method can completely envelop the actual internal force,but the calculation results of upper and lower shear wall structures are relatively safe;while the calculation results of layer augmentation coefficient method are more accurate on the basis of ensuring safety;and the variation of displacement and internal force can be well simulated by using the method of storey increase coefficient in the height range of the lower frame structure of transfer storey.(3)When the integral increase coefficient method is used in the height range of the upper shear wall structure of the transfer story,the calculation method of equivalent lateral stiffness is proposed.That is to say,by comparing the two methods of calculating the equivalent lateral stiffness of the structure,it is concluded that the accuracy of calculating the equivalent lateral stiffness of the structure with constraints on the horizontal displacement of the right side column of the lower frame structure is higher.(4)The applicability of stiffness reduction factor in frame-supported shear wall structure is analyzed.The results show that the current code can be applied to the frame-supported shear wall structure,whether it is the high-standard reduction scheme or the concrete standard reduction scheme.Only for the lower frame structure,the analysis results of concrete standard reduction scheme are more accurate.For the upper shear wall structure,the error of analysis results of high gauge reduction scheme is smaller.Therefore,a comprehensive stiffness reduction scheme is proposed,that is,stiffness reduction coefficient is 0.4 for beam reduction,0.6 for column reduction and 0.5 for upper shear wall reduction.Its rationality is verified by an example.