A single-room,single-storey full-scale brick masonry building with precast RC roofing system was tested thrice under displacement controlled lateral cyclic loading,to assess the effectiveness of the basic repair and s...A single-room,single-storey full-scale brick masonry building with precast RC roofing system was tested thrice under displacement controlled lateral cyclic loading,to assess the effectiveness of the basic repair and seismic strengthening techniques.Initially,the virgin building specimen was loaded laterally to f^tilure.In the second stage,the damaged building was repaired by stitching across the cracks,and tested under the same lateral loading.In the third stage,the twice-damaged structure was repaired once more by stitching and strengthened by twin lintel belt in steel and vertical comer reinforcement, and re-tested.The building strengthened by twin lintel belt in steel showed about 28% higher strength under lateral loading than the virgin building.展开更多
In mountainous areas, geological disasters carrying large boulders can cause severe damage to the widely used masonry buildings due to the high impact forces. To better understand the damage of brick masonry buildings...In mountainous areas, geological disasters carrying large boulders can cause severe damage to the widely used masonry buildings due to the high impact forces. To better understand the damage of brick masonry buildings under the impact of boulders, a "block-joint" model is developed using threedimensional discontinuous deformation analysis(3-D DDA) to simulate the behaviour of the "brick-mortar" structure. The "block-joint" model is used to capture not only the large displacement and deformation of individual bricks but also the large-scale sliding and opening along the mortar between the bricks. The linear elastic constitutive model is applied to account for the non-plastic deformation behaviour of brick materials. Furthermore, the mechanical characteristics of the mortar are represented using the Mohr-Coulomb and Drucker-Prager criteria. To propose safe structural design schemes and effective reinforcement for brick masonry buildings, seven construction techniques are considered, includingdifferent grades of brick and mortar, effective shear areas and reinforced members. The proposed 3-D DDA model is used to analyse the velocity distribution and the key point displacements of the brick masonry building under the impact of boulders. The results show that upgrading the brick and mortar, increasing the wall thickness, making full use of the wall thickness, and adding a circular beam and structural column are very effective approaches for improving the impact resistance of brick masonry buildings.展开更多
Past earthquake disasters in Greece, during the last thirty years, demonstrate that the severity of destruction is not only due to the intensity of the seismic event but also to the urbanization of the affected region...Past earthquake disasters in Greece, during the last thirty years, demonstrate that the severity of destruction is not only due to the intensity of the seismic event but also to the urbanization of the affected region and the vulnerability of certain types of buildings. Considerable damage was sustained by both old unreinforced masonry structures as well as by relatively new multistory reinforced concrete structures with ＂soft story＂ at their ground floor level. The most important observations made during six past earthquake disasters are presented in a summary form and discussed. The most remarkable case of extensive structural damage was caused from the resent Athens 1999 earthquake. The consequent discussion focuses on the following issues： （1） Classification of structural damage and their underlying causes. （2） Repair and strengthening of damaged structures. （3） Upgrade the seismic design. （4） Plans for earthquake preparedness. （5） Assessing the vulnerability of certain type of structures （schools, hospitals, public buildings etc）. （6） Education specialized in earthquake engineering. （7） The enrichment of the strong motion data base.展开更多
文摘A single-room,single-storey full-scale brick masonry building with precast RC roofing system was tested thrice under displacement controlled lateral cyclic loading,to assess the effectiveness of the basic repair and seismic strengthening techniques.Initially,the virgin building specimen was loaded laterally to f^tilure.In the second stage,the damaged building was repaired by stitching across the cracks,and tested under the same lateral loading.In the third stage,the twice-damaged structure was repaired once more by stitching and strengthened by twin lintel belt in steel and vertical comer reinforcement, and re-tested.The building strengthened by twin lintel belt in steel showed about 28% higher strength under lateral loading than the virgin building.
基金sponsored by the National Science & Technology Pillar Programme of the Ministry of Science and Technology of China (Grant No. 2014BAL05B01)National Natural Science Foundation of China (Grant No. 51708420)+3 种基金Shanghai Pujiang Program (Grant No. 17PJ1409100)Natural Science Foundation of Shanghai (Grant No. 17ZR1432300)the Fundamental Research Funds for the Central Universities (Grant No. 2016KJ024)the Shanghai Peak Discipline Program for Higher Education Institutions (Class I)-Civil Engineering
文摘In mountainous areas, geological disasters carrying large boulders can cause severe damage to the widely used masonry buildings due to the high impact forces. To better understand the damage of brick masonry buildings under the impact of boulders, a "block-joint" model is developed using threedimensional discontinuous deformation analysis(3-D DDA) to simulate the behaviour of the "brick-mortar" structure. The "block-joint" model is used to capture not only the large displacement and deformation of individual bricks but also the large-scale sliding and opening along the mortar between the bricks. The linear elastic constitutive model is applied to account for the non-plastic deformation behaviour of brick materials. Furthermore, the mechanical characteristics of the mortar are represented using the Mohr-Coulomb and Drucker-Prager criteria. To propose safe structural design schemes and effective reinforcement for brick masonry buildings, seven construction techniques are considered, includingdifferent grades of brick and mortar, effective shear areas and reinforced members. The proposed 3-D DDA model is used to analyse the velocity distribution and the key point displacements of the brick masonry building under the impact of boulders. The results show that upgrading the brick and mortar, increasing the wall thickness, making full use of the wall thickness, and adding a circular beam and structural column are very effective approaches for improving the impact resistance of brick masonry buildings.
文摘Past earthquake disasters in Greece, during the last thirty years, demonstrate that the severity of destruction is not only due to the intensity of the seismic event but also to the urbanization of the affected region and the vulnerability of certain types of buildings. Considerable damage was sustained by both old unreinforced masonry structures as well as by relatively new multistory reinforced concrete structures with ＂soft story＂ at their ground floor level. The most important observations made during six past earthquake disasters are presented in a summary form and discussed. The most remarkable case of extensive structural damage was caused from the resent Athens 1999 earthquake. The consequent discussion focuses on the following issues： （1） Classification of structural damage and their underlying causes. （2） Repair and strengthening of damaged structures. （3） Upgrade the seismic design. （4） Plans for earthquake preparedness. （5） Assessing the vulnerability of certain type of structures （schools, hospitals, public buildings etc）. （6） Education specialized in earthquake engineering. （7） The enrichment of the strong motion data base.
