Research On Reliability Of Shear Capacity Of Reinforced Masonry Shear Walls Based On Database

This paper compared the design formula of reinforced masonry shear wall's shear strength in the China and the United States and New Zealand three countries' current national masonry codes. It has been found that Chinese code design formula was more conservative when considering the contribution of masonry to wall's shear strength and overestimated the contribution of horizontal reinforcing to wall's shear strength while compared to the United States and New Zealand code design formula.This paper have collected data from masonry shear wall shear test around the world and set up a database including a total of 118 pieces of test wall. This database has been used to calculate and compare the deviation and reliability of three countries' code design formula. Results showed that Chinese code design formula was more conservative in calculating the contribution of masonry to wall's shear strength and overestimated the contribution of horizontal reinforcing to wall's shear strength. The three counties' code design formula could meet the requirement ofreliability, Chinese code design formula had the most safety margin withconservative design. The United States code design formula was more reasonable, and New Zealand code design formula was in between.Referring to the results of the comparative analysis and the fitting analysis results from database, some adjustments for parameters in the average calculation formula of Chinese code have been made. The deviation of the modified formula has been calculated and compared with the original formula. It has been found that the modified formula could reflect the shear strength of reinforced masonry shear wall more accurately and reasonably.A new design formula based on the modified formula has been set up, and the deviation and reliability of new design formula have been calculated and compared with the original design formula. Results demonstrated that the new design formula could slightly reduce the conservation existed in the original design formula when calculating the contribution of masonry to wall's shear strength and still overestimated the contribution of horizontal reinforcing to wall's shear strength. Even though the reliability has been decreased, it still meets the requirements of specification. Therefore, the new design formula could be more reasonable in the design.