Study on Earthquake Damage Distribution of Multistory Masonry Buildings
The main components which affect the earthquake damage grades classification of multistory masonry build- ings and the damage characters are summarized and analyzed through the statistics and analysis of a large number of pre- vious earthquake damage data. According to the standard of earthquake damage grades classification, the damage num- bers of each component of multistory masonry buildings under different earthquake damage indexes are analyzed quanti- tatively and the calculation formulas based on the relationship between the damage numbers of components and the earth- quake damage index under different cases are given; Based on the structural analysis of multistory masonry buildings and the research of earthquake damage data, the calculation formulas of the earthquake damage distributions in different floors and main components' different positions on the same floor of multistory masonry buildings are given, which provides us a platform to objectively understand the earthquake damage distribution of multistory masonry buildings; The earthquake damage distribution is an important factor to affect the realistic degree of the 3-D damage models in the scene simulation system for earthquake disaster, this paper also provides a theoretical basis for the modeling of the 3-D damage models of multistory masonry structure; Finally, the earthquake damage distribution of the bearing wall of a five-storey masonry building in the minor damage has been given as an example.
Allowable Torsional Eccentricity for the Simplified Method for the Seismic Analysis of Low-Rise Confined Masonry Shear-Wall Buildings of Mexican Codes
A parametric study devoted to assess the limiting value for the static eccentricity (es) for the application of the simplified method for seismic analysis (SMSA) of bearing-wall confined masonry structures of Mexican Building Codes is presented. Based upon the results of a comprehensive parametric study, limiting values for es for the use of the SMSA are proposed for three different performance levels for the structure: (a) elastic response, (b) completely nonlinear (cracked) response of all walls along the building height and, (c) partially nonlinear (cracked) response along the height. The criterion used to propose limiting values for es was that the underestimation of shear forces predicted for the first story walls with the SMSA was within reasonable limits with respect to those shear forces computed with a rigorous 3D static analysis using an equivalent linearization for the nonlinear (cracked) response of the walls, in order to insure reasonably safe designs of such structures.
Interaction of Diclofop-Methyl and MCPA on Wild Oats (Avena fatua)
Diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoate} loses part of its activity on wild oats (Avena fatua L.) when it is applied in combination with ester or amine formulations of MCPA {[4-chloro-o-tolyl)oxy] acetic acid.} Uptake of diclofop-methyl is reduced in the presence of commercial formulations of MCPA, particularly amine formulations, which are only partly compatible with the diclofop-methyl formulation. With added MCPA, regardless of formulation, hydrolysis of diclofop-methyl to the acid diclofop is slowed down, both in intact wild oat plants and in a crude leaf extract. At the same time, conversion of any acid formed to inactive conjugates is accelerated in the presence of MCPA. It is concluded that the loss of activity of diclofop-methyl by MCPA can be accounted for by the effects of MCPA on uptake and metabolic conversion of diclofop-methyl.