This paper proposes a modeling system developed in order to analyze the urban freight transport and logistics within urban and metropolitan areas. A review of models developed to simulate this segment of mobility is a...This paper proposes a modeling system developed in order to analyze the urban freight transport and logistics within urban and metropolitan areas. A review of models developed to simulate this segment of mobility is also reported. The review analysis highlights the limits of models for the ex-ante assessment of city logistics measures. For this reason this paper proposes a new modeling system approach for the assessment of city logistics measures. It is made of different steps approaching problems related to quantity OD （Origin-Destination） flows, restocking type OD flows, delivery OD flows, delivery OD flows for time slice and vehicle type, and vehicle OD flows. This modeling system has been specified and calibrated using some surveys carried out in the inner area of Rome where more than 500 truck drivers and more than 600 retailers have been interviewed.展开更多
There is a variety of PDSs （project delivery systems） in today＇s construction industry. This leads to confusion when it comes to selecting the most suitable PDS for a specific project. The wrong selection decision ...There is a variety of PDSs （project delivery systems） in today＇s construction industry. This leads to confusion when it comes to selecting the most suitable PDS for a specific project. The wrong selection decision might lead eventually to reduced profit margins or perhaps financial losses to PSFs （professional service firms）. This research proposes a conceptual framework that helps PSFs in the selection of one or more suitable PDSs for their construction operations. The framework uses SWOT （strengths, weaknesses, opportunities and threats） analysis as a tool for assessing each PDS considered in this research. The PDSs included in the framework are design-bid-build, design-build, construction management agency, public-private partnerships and integrated project delivery. The main aim of this research framework is to enhance decision-making efficiency in PDS selection for PSF operations.展开更多
The construction industry in Botswana has been identified as an industry with many problems. Currently the Botswana government uses the design-bid-build process, using prequalification and awards to the lowest bidder ...The construction industry in Botswana has been identified as an industry with many problems. Currently the Botswana government uses the design-bid-build process, using prequalification and awards to the lowest bidder for construction services. The government can also use the design-build delivery system. The current delivery system uses an engineering group that delivers designs and construction, uses a procurement group to award the contract and contract modifications. However, the analysis for all actions is done by the engineering group. The model is very similar to the Corps of Engineers traditional processes in the United States. Construction performance （on time and no contract deviations） has not been good. The authors propose that the delivery system and the paradigm of direction, control and decision making by the engineering group causes risk to the project and results in poor contractor performance. The authors suggest making modifications in the process and to use the design-build process. The authors also propose to change the paradigm using best value PIPS/IMT concepts.展开更多
The aim of this paper is to verify the existence of a clause in contracts of promise of property sale which defines the consequences of delay in the delivery of property, and to discover whether owners demanded any co...The aim of this paper is to verify the existence of a clause in contracts of promise of property sale which defines the consequences of delay in the delivery of property, and to discover whether owners demanded any compensation for delays occurred. The number of buildings delivered after the scheduled deadline in two cities between December 2009 and January 2011 was found （n = 542）, and a sample of 82 residential units was taken. In order to obtain the data, a semi-structured questionnaire was given to the homeowners. It was observed that only 35% （n = 29） of the contracts included a penalty clause for delay. However, in 19 of the 29 contracts the clause regarding delay came with other clauses that allowed the company to delay the delivery of the building for up to six months. This clause is considered null in Brazilian legislation. As for compensation, only one （1.82%） owner demanded that the company provide a rental property during the period of delay. It could be concluded that contractors are not observing Brazilian legislation regarding the delay in the delivery of residential units. In addition, conformism is perceived in the attitude of the homeowners.展开更多
Mosul dam is the biggest hydraulic structure in Iraq located on the River Tigris 60 km northwest of Mosul city. Its storage capacity is 11. 11 × 109 m3 and it had been in operation since 1986. A physical distorte...Mosul dam is the biggest hydraulic structure in Iraq located on the River Tigris 60 km northwest of Mosul city. Its storage capacity is 11. 11 × 109 m3 and it had been in operation since 1986. A physical distorted model with movable bed having a vertical scale 1： 100 and a horizontal scale 1：1000 was used to conduct the experiments relating the water level at the reservoir and water discharge upstream the reservoir with the bed load transport rate. The model represents the first 15 km of most northern part of Mosul dam reservoir. The construction of the model was based on bathymetric survey conducted in 2009. Twenty-four experiments were executed using four different discharges （0.5, 1.0, 1.5, and 2.0 L/s） which represent the average discharges in the flood period of River Tigris. At each individual discharge six operations were assumed where the reservoir＇s water level was 305, 307, 309, 310, 312, 315 meters above sea level respectively. In all the experiments conducted, bedload transport was measured in the physical model at section representing the River Tigris 1 km upstream the reservoir. The results showed that the bedload rate was decreasing when the water level within the reservoir was increasing. It was also evident that bedload transport rate dramatically decreased at level 310 meters above sea level onward. This is due to the fact that at this level represent the effect of backwater which was noticeable on the river cross section展开更多
Amman＇s land typology is characterized by hilly slopes, and this presents challenges and opportunities for architects and designers aiming at delivering sustainable buildings. The research focuses on the importance o...Amman＇s land typology is characterized by hilly slopes, and this presents challenges and opportunities for architects and designers aiming at delivering sustainable buildings. The research focuses on the importance of any site＇s given criteria, mainly its slope and topography on the delivery of sustainable buildings. Amman city consists broadly of two main types of buildings, apartment buildings and villas, by studying each type of building with regard to its environmental context on a given site in the city, the research seeks to identify the sustainable variables that site topography delimit or facilitate, using a set of attributes for each building type. The main objective of this research is to highlight the sustainable approach for building on sloped sites throughout the building project life-cycle in general, and to set a sustainability framework for designers during the initial design phase in particular. A number of case studies for both types of buildings are studied and analysed, and conclusions are given based on syntheses of available data from literature review or case analysis. At the end, the research provides a mechanism for the development of guidelines for sustainable and passive viability on preferred buildings orientation in hilly areas with regard to local climatic data.展开更多
文摘This paper proposes a modeling system developed in order to analyze the urban freight transport and logistics within urban and metropolitan areas. A review of models developed to simulate this segment of mobility is also reported. The review analysis highlights the limits of models for the ex-ante assessment of city logistics measures. For this reason this paper proposes a new modeling system approach for the assessment of city logistics measures. It is made of different steps approaching problems related to quantity OD （Origin-Destination） flows, restocking type OD flows, delivery OD flows, delivery OD flows for time slice and vehicle type, and vehicle OD flows. This modeling system has been specified and calibrated using some surveys carried out in the inner area of Rome where more than 500 truck drivers and more than 600 retailers have been interviewed.
文摘There is a variety of PDSs （project delivery systems） in today＇s construction industry. This leads to confusion when it comes to selecting the most suitable PDS for a specific project. The wrong selection decision might lead eventually to reduced profit margins or perhaps financial losses to PSFs （professional service firms）. This research proposes a conceptual framework that helps PSFs in the selection of one or more suitable PDSs for their construction operations. The framework uses SWOT （strengths, weaknesses, opportunities and threats） analysis as a tool for assessing each PDS considered in this research. The PDSs included in the framework are design-bid-build, design-build, construction management agency, public-private partnerships and integrated project delivery. The main aim of this research framework is to enhance decision-making efficiency in PDS selection for PSF operations.
文摘The construction industry in Botswana has been identified as an industry with many problems. Currently the Botswana government uses the design-bid-build process, using prequalification and awards to the lowest bidder for construction services. The government can also use the design-build delivery system. The current delivery system uses an engineering group that delivers designs and construction, uses a procurement group to award the contract and contract modifications. However, the analysis for all actions is done by the engineering group. The model is very similar to the Corps of Engineers traditional processes in the United States. Construction performance （on time and no contract deviations） has not been good. The authors propose that the delivery system and the paradigm of direction, control and decision making by the engineering group causes risk to the project and results in poor contractor performance. The authors suggest making modifications in the process and to use the design-build process. The authors also propose to change the paradigm using best value PIPS/IMT concepts.
文摘The aim of this paper is to verify the existence of a clause in contracts of promise of property sale which defines the consequences of delay in the delivery of property, and to discover whether owners demanded any compensation for delays occurred. The number of buildings delivered after the scheduled deadline in two cities between December 2009 and January 2011 was found （n = 542）, and a sample of 82 residential units was taken. In order to obtain the data, a semi-structured questionnaire was given to the homeowners. It was observed that only 35% （n = 29） of the contracts included a penalty clause for delay. However, in 19 of the 29 contracts the clause regarding delay came with other clauses that allowed the company to delay the delivery of the building for up to six months. This clause is considered null in Brazilian legislation. As for compensation, only one （1.82%） owner demanded that the company provide a rental property during the period of delay. It could be concluded that contractors are not observing Brazilian legislation regarding the delay in the delivery of residential units. In addition, conformism is perceived in the attitude of the homeowners.
文摘Mosul dam is the biggest hydraulic structure in Iraq located on the River Tigris 60 km northwest of Mosul city. Its storage capacity is 11. 11 × 109 m3 and it had been in operation since 1986. A physical distorted model with movable bed having a vertical scale 1： 100 and a horizontal scale 1：1000 was used to conduct the experiments relating the water level at the reservoir and water discharge upstream the reservoir with the bed load transport rate. The model represents the first 15 km of most northern part of Mosul dam reservoir. The construction of the model was based on bathymetric survey conducted in 2009. Twenty-four experiments were executed using four different discharges （0.5, 1.0, 1.5, and 2.0 L/s） which represent the average discharges in the flood period of River Tigris. At each individual discharge six operations were assumed where the reservoir＇s water level was 305, 307, 309, 310, 312, 315 meters above sea level respectively. In all the experiments conducted, bedload transport was measured in the physical model at section representing the River Tigris 1 km upstream the reservoir. The results showed that the bedload rate was decreasing when the water level within the reservoir was increasing. It was also evident that bedload transport rate dramatically decreased at level 310 meters above sea level onward. This is due to the fact that at this level represent the effect of backwater which was noticeable on the river cross section
文摘Amman＇s land typology is characterized by hilly slopes, and this presents challenges and opportunities for architects and designers aiming at delivering sustainable buildings. The research focuses on the importance of any site＇s given criteria, mainly its slope and topography on the delivery of sustainable buildings. Amman city consists broadly of two main types of buildings, apartment buildings and villas, by studying each type of building with regard to its environmental context on a given site in the city, the research seeks to identify the sustainable variables that site topography delimit or facilitate, using a set of attributes for each building type. The main objective of this research is to highlight the sustainable approach for building on sloped sites throughout the building project life-cycle in general, and to set a sustainability framework for designers during the initial design phase in particular. A number of case studies for both types of buildings are studied and analysed, and conclusions are given based on syntheses of available data from literature review or case analysis. At the end, the research provides a mechanism for the development of guidelines for sustainable and passive viability on preferred buildings orientation in hilly areas with regard to local climatic data.
