Progressive Collapse Resistance of a New Staggered Story Isolated System

A new staggered isolated system developed from the mid-story isolated system is the new staggered story isolated system. There are not many studies on this structure currently. In this study, an 18-story new staggered story isolated system model is established using SAP2000. The dynamic nonlinear dynamic alternate method is used to analyze the structure against progressive collapse. Results show that the structure has good resistance to progressive collapse, and there is no progressive collapse under each working condition. The progressive collapse does not occur for the case of removing only one vertical structural member of the new staggered of isolated system. The side column has big influence on this isolated structures’ progressive collapse;the removal of vertical structural member of the isolation layer has less impact on the structure than the removal of the bottom vertical structural member. After the removing of the member, the internal force of the structure will be redistributed, and the axial force of the adjacent columns will change obviously, showing a trend of “near large and far small”.

Economic Valuation of Emission Impact Reduction by Using Alternative Path in Yogyakarta Urban Area, Indonesia

The urban economic development needs transportation facilities. People move form one location to the other rapidly. The amount of vehicle increases, it also increases lead content in the air. The human health cost increases as lead content in the air increases. The reduction of lead content for 10 percent, it gives economic value as much as Rp. 11.828.365.993,- （US$ 985,697.17）. And if lead content decreases for 25 percent, it yields economic benefit as much as Rp. 34.509.073.173, - （US$ 2,875,765.10）. The analysis of benefit uses exposure-response function method. Analysis of people awareness for keeping the environment uses contingent valuation method survey and willingness to pay. People awareness to keep their environment and to decrease lead content is not good enough, despite the fact that there is some increase of awareness, for example the awareness of using alternative path- through ring road on peak hours.

Progressive Collapse Analysis of Concrete-Filled Steel Tubular Frames with Semi-rigid Connections

A 9-story concrete-filled steel tubular frame model is used to analyze the response of joints due to sudden column loss. Three different models are developed and compared to study the efficiency and feasibility of simulation, which include substructure model, beam element model and solid element model. The comparison results show that the substructure model has a satisfying capability, calculation efficiency and accuracy to predict the concerned joints as well as the overall framework. Based on the substructure model and a kind of semi-rigid connection for concretefilled square hollow section steel column proposed in this paper, the nonlinear dynamic analyses are conducted by the alternate path method. It is found that the removal of the ground inner column brings high-level joint moments and comparatively low-level axial tension forces. The initial stiffness and transmitted ultimate moment of the semi-rigid connection are the main factors that influence the frame behavior, and their lower limit should be guaranteed to resist collapse. Reduced ultimate moment results in drastic displacement and axial force development, which may bring progressive collapse. The higher initial stiffness ensures that the structure has a stronger capacity to resist progressive collapse.

Application of k-person and k-task maximal efficiency assignment algorithm to water piping repair

Solving the absent assignment problem of the shortest time limit in a weighted bipartite graph with the minimal weighted k-matching algorithm is unsuitable for situations in which large numbers of problems need to be addressed by large numbers of parties. This paper simplifies the algorithm of searching for the even alternating path that contains a maximal element using the minimal weighted k-matching theorem and intercept graph. A program for solving the maximal efficiency assignment problem was compiled. As a case study, the program was used to solve the assignment problem of water piping repair in the case of a large number of companies and broken pipes, and the validity of the program was verified.

A Review on Progressive Collapse Designing Based on UFC Regulation

Progressive collapse is a relatively rare event which happens due to unusual loading on a structure that lacks adequate continuity,ductility and indeterminacy which causes local collapse in that structure and then extends it to other structural parts.The US department of defense published UFC4-023-03 regulation regarding the building design against progressive collapse.This regulation,based on the ASCE 7-05 standard,introduces two general approaches to building design against progressive collapse,including direct design and indirect design approaches.In this study,a variety of structural design methods for progressive collapse have been investigated.Moreover,their strengths and weaknesses have been mentioned.In general,the results of this study show that design based on alternative path(AP)method is more economical than other methods.Moreover,application of AP method is much more commonly accepted by researchers and designers.

Injustice in Primitive Accumulation and Its Linearity： China＇s Alternative Path

Primitive accumulation refers to during industrialization. This article argues that the early phase of development this Marxist concept implicates a deeper notion of injustice, which contains logic of linearity that can be further dissected into a trichotomous part worthy of our discussion, namely, temporal ordering, harsh treatment, and inhumane consequences. This ＂linearity＂ as assumed in this concept, nevertheless, was not unchallenged in history. As a matter of fact, in Mao＇s era, China deliberately sought an alternative path to the capitalist mode by attending to social welfare, physical well-being and rights protection for workers. This part of history is well worth re-investigation and re-interpretation.

Deep reinforcement learning-based critical element identification and demolition planning of frame structures

This paper proposes a framework for critical element identification and demolition planning of frame structures.Innovative quantitative indices considering the severity of the ultimate collapse scenario are proposed using reinforcement learning and graph embedding.The action is defined as removing an element,and the state is described by integrating the joint and element features into a comprehensive feature vector for each element.By establishing the policy network,the agent outputs the Q value for each action after observing the state.Through numerical examples,it is confirmed that the trained agent can provide an accurate estimation of the Q values,and handle problems with different action spaces owing to utilization of graph embedding.Besides,different behaviors can be learned by varying hyperparameters in the reward function.By comparing the proposed method and the conventional sensitivity index-based methods,it is demonstrated that the computational cost is considerably reduced because the reinforcement learning model is trained offline.Besides,it is proved that the Q values produced by the reinforcement learning agent can make up for the deficiencies of existing indices,and can be directly used as the quantitative index for the decision-making for determining the most expected collapse scenario,i.e.,the sequence of element removals.

Investigation on a mitigation scheme to resist the progressive collapse of reinforced concrete buildings

This study presents the investigation of the approach which was presented by Thaer M.Saeed Alrudaini to provide the alternate load path to redistribute residual loads and preventing from the potential progressive collapse of RC buildings.It was proposed to transfer the residual loads upwards above the failed column of RC buildings by vertical cables hanged at the top to a hat steel braced frame seated on top of the building which in turn redistributes the residual loads to the adjacent columns.In this study a ten-storey regular structural building has been considered to investigate progressive collapse potential.Structural design is based on ACI 318-08 concrete building code for special RC frames and the nonlinear dynamic analysis is carried out using SAP2000 software,following UFC4-023-03 document.Nine independent failure scenarios are adopted in the investigation,including six external removal cases in different floors and three removal cases in the first floor.A new detail is proposed by using barrel and wedge to improve residual forces transfer to the cables after removal of the columns.Simulation results show that progressive collapse of building that resulted from potential failure of columns located in floors can be efficiently resisted by using this method.