In view of the current situation of aging, functional decline and protection difficulties in historic blocks, the feasibility of commercial regeneration is discussed. Referring to the relevant theories of protection a...In view of the current situation of aging, functional decline and protection difficulties in historic blocks, the feasibility of commercial regeneration is discussed. Referring to the relevant theories of protection and renewal of historic blocks, field investigation and expert consultation, fuzzy evaluation method and analytic hierarchy process are introduced to carry out a research study on the spatial adaptability of historic blocks for commercial regeneration and establish a preliminary evaluation system. An example of Dongguan Street Historic Block in Dalian is used to test the evaluation system. This provides a basis for the formulation of commercial regeneration strategy in the next stage.展开更多
A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analy...A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analysis theory.The soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield criterion.Block analysis technique is employed to investigate the collapse of 3DRT.The model is divided into five different block types and added up to ten rigid blocks.According to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search proceeding.The results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square trapdoors.The critical stability ratios can be used in the design of underground excavation and support force.展开更多
The synergistic relationship between urban functions and street networks has al-ways been a focus in the field of urban research and practice.From the perspective of street networks,by adopting space syntax,this study...The synergistic relationship between urban functions and street networks has al-ways been a focus in the field of urban research and practice.From the perspective of street networks,by adopting space syntax,this study analyzed the deep structural characteristics and potential evolution rules of commercial blocks attached to street networks in different periods,as well as the corresponding economic,political,and cultural characteristics of an-cient Beijing city over the past 800 years.By combining these with changes in the street network,we further explained the function mechanism of layout and level adjustment in commercial blocks,and the influence of the street network on commercial blocks in the process of historical change.The main conclusions included the following:(1)The urban centripetal-centrifugal siphon effect:the layout form,topological structure,and traffic mode changes in the street network had corresponding guidance for the layout and hierarchical system of commercial blocks,while the centripetal development of the street network could guide the agglomeration effect of commercial blocks,although centrifugal development caused commercial blocks to display outward evacuation.(2)Stage transformation from mu-tation node to smooth development:the layout of commercial blocks came to depend on the ability to cross the commuting flow center,which originally relied on the accessibility of transportation nodes as local centers.Changes in traffic modes mainly affected the adjust-ment of the first-level commercial blocks,which easily led to overall layout mutation.Traffic levels have an obvious positive hierarchical relation with the second-and third-level com-mercial blocks.(3)The adaptation of traditional commercial blocks to the needs of a modern city:affected by the different emerging times and unevenness of the original commercial foundation,commercial blocks have formed various developmental models that meet the needs of modernization,and reach a balance between cultural continuity and functional ad-aptation.展开更多
文摘In view of the current situation of aging, functional decline and protection difficulties in historic blocks, the feasibility of commercial regeneration is discussed. Referring to the relevant theories of protection and renewal of historic blocks, field investigation and expert consultation, fuzzy evaluation method and analytic hierarchy process are introduced to carry out a research study on the spatial adaptability of historic blocks for commercial regeneration and establish a preliminary evaluation system. An example of Dongguan Street Historic Block in Dalian is used to test the evaluation system. This provides a basis for the formulation of commercial regeneration strategy in the next stage.
基金the Fundamental Research Funds for the Provincial Universities,China(No.702/000007020303)。
文摘A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analysis theory.The soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield criterion.Block analysis technique is employed to investigate the collapse of 3DRT.The model is divided into five different block types and added up to ten rigid blocks.According to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search proceeding.The results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square trapdoors.The critical stability ratios can be used in the design of underground excavation and support force.
基金National Natural Science Foundation of China,No.51778005Sino-German Center(National Natural Science Foundation of China and German Science Foundation),No.GZ1201
文摘The synergistic relationship between urban functions and street networks has al-ways been a focus in the field of urban research and practice.From the perspective of street networks,by adopting space syntax,this study analyzed the deep structural characteristics and potential evolution rules of commercial blocks attached to street networks in different periods,as well as the corresponding economic,political,and cultural characteristics of an-cient Beijing city over the past 800 years.By combining these with changes in the street network,we further explained the function mechanism of layout and level adjustment in commercial blocks,and the influence of the street network on commercial blocks in the process of historical change.The main conclusions included the following:(1)The urban centripetal-centrifugal siphon effect:the layout form,topological structure,and traffic mode changes in the street network had corresponding guidance for the layout and hierarchical system of commercial blocks,while the centripetal development of the street network could guide the agglomeration effect of commercial blocks,although centrifugal development caused commercial blocks to display outward evacuation.(2)Stage transformation from mu-tation node to smooth development:the layout of commercial blocks came to depend on the ability to cross the commuting flow center,which originally relied on the accessibility of transportation nodes as local centers.Changes in traffic modes mainly affected the adjust-ment of the first-level commercial blocks,which easily led to overall layout mutation.Traffic levels have an obvious positive hierarchical relation with the second-and third-level com-mercial blocks.(3)The adaptation of traditional commercial blocks to the needs of a modern city:affected by the different emerging times and unevenness of the original commercial foundation,commercial blocks have formed various developmental models that meet the needs of modernization,and reach a balance between cultural continuity and functional ad-aptation.
