A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the u...A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the ultimate equilibrium method. Based on the results of finite element analysis, the stress contour graphs and displacement vector graphs at different construction steps were obtained, and the behavior of the slope during stabilization construction process was analyzed quantitatively. Based on the analysis of safety factors of three different schemes of stabilization and two different construction schemes, the assessment of stability and bracing design of the construction process were performed. The results show that the original reinforcement design is improper; the stability of the rock slope is controlled by a developed structural plane, the stability factor after excavation is less than 1, and the free surface should be braced in time; for stability, the construction sequence should adopt that bracing follows excavation step by step up to down; the local slide occurred during the construction process agrees with the dangerous slide determined by the numerical analysis, which proves the validity and rationality of the adopted method.展开更多
Quality traceability plays an essential role in assembling and welding offshore platform blocks.The improvement of the welding quality traceability system is conducive to improving the durability of the offshore platf...Quality traceability plays an essential role in assembling and welding offshore platform blocks.The improvement of the welding quality traceability system is conducive to improving the durability of the offshore platform and the process level of the offshore industry.Currently,qualitymanagement remains in the era of primary information,and there is a lack of effective tracking and recording of welding quality data.When welding defects are encountered,it is difficult to rapidly and accurately determine the root cause of the problem from various complexities and scattered quality data.In this paper,a composite welding quality traceability model for offshore platform block construction process is proposed,it contains the quality early-warning method based on long short-term memory and quality data backtracking query optimization algorithm.By fulfilling the training of the early-warning model and the implementation of the query optimization algorithm,the quality traceability model has the ability to assist enterprises in realizing the rapid identification and positioning of quality problems.Furthermore,the model and the quality traceability algorithm are checked by cases in actual working conditions.Verification analyses suggest that the proposed early-warningmodel for welding quality and the algorithmfor optimizing backtracking requests are effective and can be applied to the actual construction process.展开更多
In order to improve the efficiency of EPS integral thermal insulation building design and optimize the construction process of insulation construction, this paper uses experiment parts and simulation form to design th...In order to improve the efficiency of EPS integral thermal insulation building design and optimize the construction process of insulation construction, this paper uses experiment parts and simulation form to design the thermal insulation construction process, and evaluates the effect of heat preservation. Based on the finite element theory this paper designs adding process of insulation material EPS in the thermal insulation layer, and establishes the radiation heat conduction model of EPS material, finally obtains the solid heat conduction equation. Finally this paper uses ANSYS software to do simulation on the strength and temperature of EPS construction, and evaluates the quality of construction works, which provides technical reference for the design of integrated thermal insulation buildings.展开更多
The complexity of geotechnical engineering and variability in construction circumstances of large extra caissons make the problem of maintaining appropriate sink attitude quite difficult, especially in keeping sink un...The complexity of geotechnical engineering and variability in construction circumstances of large extra caissons make the problem of maintaining appropriate sink attitude quite difficult, especially in keeping sink uniformity and achieving the expected final sink depth. A new construction control method is presented using ∞H theory, considering uncertainties in the mechanics model and external noise in the construction site parameters. The design method of an ∞H controller has consequently been obtained for large extra caissons. Control results using only constructor experiences are compared with simulation results using the ∞ H controller for a practical engineering situation, which indicates that the ∞H controller is successful in maintaining sink uniformity, avoiding sink as well as in achieving the expected final sink depth.展开更多
Within the project preparation phase, experienced professionals manually map design information onto process information with the aim to develop realistic and practical schedules. Unfortunately, the mapping itself is ...Within the project preparation phase, experienced professionals manually map design information onto process information with the aim to develop realistic and practical schedules. Unfortunately, the mapping itself is neither part of any underlying data model nor is it supported by current scheduling tools. As a consequence the process of setting up the data model for a schedule is still not supported formally. Huhnt and Enge described a modelling technique that addresses the missing linkage between design and process information[1]. The approach makes use of so called component types. These are template sub-processes that describe the fabrication procedure of typical building components. Decomposing the building into com-ponents and assigning a component type to each component allows for formal support while scheduling. Depending on the decomposition of the building into components and the complexity of the involved component types the specification effort differs. The question about optimal component types arises: Which layout of building components and component types results in minimal specification effort? This paper presents a branch and bound algorithm to determine optimal component types. For a given schedule, which has been modelled based on component types, all possible decompositions into sub-processes are determined. During the decomposition process the encountered configurations are compared. Those with minimal specifica-tion effort are registered. Theoretical and practical examples are examined and discussed.展开更多
This paper presents an approach to handle different types of subsequent modifications in construction processes. It is focused on a formalized approach with the objective that effects of subsequent modifications are d...This paper presents an approach to handle different types of subsequent modifications in construction processes. It is focused on a formalized approach with the objective that effects of subsequent modifications are detected automatically. The approach presented in this paper makes use of an existing modeling technique specifically focused on construction processes. The modeling techniques result in a process description where all technological interdependencies between construction activities are considered and where consistency between the sequence of activities and the history of components is guaran-teed. This modeling technique is expanded by an existing concept for handling versions and dependencies between objects. The integration of these different concepts makes it possible to track effects of relevant types of subsequent modifications in construction processes on a formalized basis. Effects of subsequent modifications are detected by algorithms, different versions can be compared by algorithms and different versions are stored so that subsequent modifications are documented. The innovation of the approach presented is the completeness. Effects of different relevant types of subsequent modifications in construction processes are tracked on a formalized basis.展开更多
The three-hinge precast arch culvert consists of two segmental precast units and three hinge points.It harnesses the passive resistance of an embankment by permitting deflection,resulting in a mechanically stable stru...The three-hinge precast arch culvert consists of two segmental precast units and three hinge points.It harnesses the passive resistance of an embankment by permitting deflection,resulting in a mechanically stable structure.However,the design of the three-hinge precast arch culvert differs from that of a conventional culvert,prompting the mechanical behavior of the culvert to become an important issue.In this study,therefore,1/5 scale model tests were conducted on a three-hinge precast arch culvert to measure the changes in the inside width and earth pressure acting on the culvert at each step in order to investigate the culvert’s mechanical behavior at each construction stage.Moreover,the deflection measurement of the culvert was obtained at the in-situ construction site.The results indicate that the arch members were displaced according to the embankment depth in a similar manner to the design load.Therefore,the horizontal earth pressure,which was larger than the earth pressure at rest,acted on the culvert at the end of its construction.展开更多
Urbanization has led to the rapid development of the construction industry.However,this has also led to higher requirements for the construction engineering management.Other than the quality monitoring of engineering ...Urbanization has led to the rapid development of the construction industry.However,this has also led to higher requirements for the construction engineering management.Other than the quality monitoring of engineering construction,the energy-saving properties of the building should also be considered.Therefore,a scientific management approach should be adopted to improve green building management.This paper primarily examines the importance of quality management in green building construction,along with the factors influencing it.It also identifies the quality issues present in current green building construction.Finally,it proposes measures for quality management in the green building construction process to facilitate the industry’s healthy development.展开更多
In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expan...In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expansion of highway construction,power supply,and distribution has led to several challenges in mechanical and electrical engineering technology.Ensuring the safe,stable,and cost-effective operation of the power supply and distribution system to meet the diverse requirements of highway operations has become a pressing issue.This article takes an example of a highway electromechanical engineering power supply and distribution construction project to provide insight into the construction process of highway electromechanical engineering power supply and distribution technology.展开更多
A newnumerical method based on vector form intrinsic finite element（VFIFE） is proposed to simulate the integral lifting process of steel structures. First, in order to verify the validity of the VFIFE method, taking...A newnumerical method based on vector form intrinsic finite element（VFIFE） is proposed to simulate the integral lifting process of steel structures. First, in order to verify the validity of the VFIFE method, taking the steel gallery between the integrated building and the attached building of Nanjing M obile Communication Buildings for example, the static analysis was carried out and the corresponding results were compared with the results achieved by the traditional finite element method. Then, according to the characteristics of dynamic construction of steel structure integral lifting, the tension cable element was employed to simulate the behavior of dynamic construction. The VFIFE method avoids the iterative solution of the stiffness matrix and the singularity problems. Therefore, it is simple to simulate the complete process of steel structure lifting construction.Finally, by using the VFIFE, the displacement and internal force time history curves of the steel structures under different lifting speeds are obtained. The results show that the lifting speed has influence on the lifting force, the internal force, and the displacement of the structure. In the case of normal lifting speed, the dynamic magnification factor of 1. 5 is safe and reasonable for practical application.展开更多
Time and cost are two of the most important factors to consider in each construction project. In order to maximize performance, both the client and the contractor will work to optimize both the duration of the project...Time and cost are two of the most important factors to consider in each construction project. In order to maximize performance, both the client and the contractor will work to optimize both the duration of the project and its cost. We show a model of linear entire mixed programming to solve the considered problem. The aim is to minimize the project total time, by means of the assignment of equipments of work to the different production lines of the activities to realizing. The fundamental beginning is to support the same production （rate of production in meters/day of the activity in view of the equipment of work） for tbe different equipments to achieve the maximum efficiency in each period of time. With the limited availability of resources, the work must be continuous and the period of time between operations and final must be kept. However, this paper also presents the bibliographical study on methodologies of the optimization of construction processes in response to the two objectives： time and cost. This will consider the use of recta-heuristic techniques, such as population based algorithms.展开更多
基金Scientific and Technological Support and Guidance Plan Projects of Zhejiang Province(Grant No.2008C23019)
文摘A self-developed elasto-plastic finite element program was used to analyze the construction sequence of high rock slope's stabilization in a coal-coking plant, and the result was compared with that employing the ultimate equilibrium method. Based on the results of finite element analysis, the stress contour graphs and displacement vector graphs at different construction steps were obtained, and the behavior of the slope during stabilization construction process was analyzed quantitatively. Based on the analysis of safety factors of three different schemes of stabilization and two different construction schemes, the assessment of stability and bracing design of the construction process were performed. The results show that the original reinforcement design is improper; the stability of the rock slope is controlled by a developed structural plane, the stability factor after excavation is less than 1, and the free surface should be braced in time; for stability, the construction sequence should adopt that bracing follows excavation step by step up to down; the local slide occurred during the construction process agrees with the dangerous slide determined by the numerical analysis, which proves the validity and rationality of the adopted method.
基金funded by Ministry of Industry and Information Technology of the People’s Republic of China[Grant No.2018473].
文摘Quality traceability plays an essential role in assembling and welding offshore platform blocks.The improvement of the welding quality traceability system is conducive to improving the durability of the offshore platform and the process level of the offshore industry.Currently,qualitymanagement remains in the era of primary information,and there is a lack of effective tracking and recording of welding quality data.When welding defects are encountered,it is difficult to rapidly and accurately determine the root cause of the problem from various complexities and scattered quality data.In this paper,a composite welding quality traceability model for offshore platform block construction process is proposed,it contains the quality early-warning method based on long short-term memory and quality data backtracking query optimization algorithm.By fulfilling the training of the early-warning model and the implementation of the query optimization algorithm,the quality traceability model has the ability to assist enterprises in realizing the rapid identification and positioning of quality problems.Furthermore,the model and the quality traceability algorithm are checked by cases in actual working conditions.Verification analyses suggest that the proposed early-warningmodel for welding quality and the algorithmfor optimizing backtracking requests are effective and can be applied to the actual construction process.
文摘In order to improve the efficiency of EPS integral thermal insulation building design and optimize the construction process of insulation construction, this paper uses experiment parts and simulation form to design the thermal insulation construction process, and evaluates the effect of heat preservation. Based on the finite element theory this paper designs adding process of insulation material EPS in the thermal insulation layer, and establishes the radiation heat conduction model of EPS material, finally obtains the solid heat conduction equation. Finally this paper uses ANSYS software to do simulation on the strength and temperature of EPS construction, and evaluates the quality of construction works, which provides technical reference for the design of integrated thermal insulation buildings.
文摘The complexity of geotechnical engineering and variability in construction circumstances of large extra caissons make the problem of maintaining appropriate sink attitude quite difficult, especially in keeping sink uniformity and achieving the expected final sink depth. A new construction control method is presented using ∞H theory, considering uncertainties in the mechanics model and external noise in the construction site parameters. The design method of an ∞H controller has consequently been obtained for large extra caissons. Control results using only constructor experiences are compared with simulation results using the ∞ H controller for a practical engineering situation, which indicates that the ∞H controller is successful in maintaining sink uniformity, avoiding sink as well as in achieving the expected final sink depth.
文摘Within the project preparation phase, experienced professionals manually map design information onto process information with the aim to develop realistic and practical schedules. Unfortunately, the mapping itself is neither part of any underlying data model nor is it supported by current scheduling tools. As a consequence the process of setting up the data model for a schedule is still not supported formally. Huhnt and Enge described a modelling technique that addresses the missing linkage between design and process information[1]. The approach makes use of so called component types. These are template sub-processes that describe the fabrication procedure of typical building components. Decomposing the building into com-ponents and assigning a component type to each component allows for formal support while scheduling. Depending on the decomposition of the building into components and the complexity of the involved component types the specification effort differs. The question about optimal component types arises: Which layout of building components and component types results in minimal specification effort? This paper presents a branch and bound algorithm to determine optimal component types. For a given schedule, which has been modelled based on component types, all possible decompositions into sub-processes are determined. During the decomposition process the encountered configurations are compared. Those with minimal specifica-tion effort are registered. Theoretical and practical examples are examined and discussed.
文摘This paper presents an approach to handle different types of subsequent modifications in construction processes. It is focused on a formalized approach with the objective that effects of subsequent modifications are detected automatically. The approach presented in this paper makes use of an existing modeling technique specifically focused on construction processes. The modeling techniques result in a process description where all technological interdependencies between construction activities are considered and where consistency between the sequence of activities and the history of components is guaran-teed. This modeling technique is expanded by an existing concept for handling versions and dependencies between objects. The integration of these different concepts makes it possible to track effects of relevant types of subsequent modifications in construction processes on a formalized basis. Effects of subsequent modifications are detected by algorithms, different versions can be compared by algorithms and different versions are stored so that subsequent modifications are documented. The innovation of the approach presented is the completeness. Effects of different relevant types of subsequent modifications in construction processes are tracked on a formalized basis.
基金supported by the National Institute for Land and Infrastructure Management,MLIT,Japan(grant for the research and development of technologies for improving the quality of road policies,no.24-4,2012-2015).
文摘The three-hinge precast arch culvert consists of two segmental precast units and three hinge points.It harnesses the passive resistance of an embankment by permitting deflection,resulting in a mechanically stable structure.However,the design of the three-hinge precast arch culvert differs from that of a conventional culvert,prompting the mechanical behavior of the culvert to become an important issue.In this study,therefore,1/5 scale model tests were conducted on a three-hinge precast arch culvert to measure the changes in the inside width and earth pressure acting on the culvert at each step in order to investigate the culvert’s mechanical behavior at each construction stage.Moreover,the deflection measurement of the culvert was obtained at the in-situ construction site.The results indicate that the arch members were displaced according to the embankment depth in a similar manner to the design load.Therefore,the horizontal earth pressure,which was larger than the earth pressure at rest,acted on the culvert at the end of its construction.
文摘Urbanization has led to the rapid development of the construction industry.However,this has also led to higher requirements for the construction engineering management.Other than the quality monitoring of engineering construction,the energy-saving properties of the building should also be considered.Therefore,a scientific management approach should be adopted to improve green building management.This paper primarily examines the importance of quality management in green building construction,along with the factors influencing it.It also identifies the quality issues present in current green building construction.Finally,it proposes measures for quality management in the green building construction process to facilitate the industry’s healthy development.
文摘In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expansion of highway construction,power supply,and distribution has led to several challenges in mechanical and electrical engineering technology.Ensuring the safe,stable,and cost-effective operation of the power supply and distribution system to meet the diverse requirements of highway operations has become a pressing issue.This article takes an example of a highway electromechanical engineering power supply and distribution construction project to provide insight into the construction process of highway electromechanical engineering power supply and distribution technology.
基金The National Natural Science Foundation of China(No.51308105)
文摘A newnumerical method based on vector form intrinsic finite element（VFIFE） is proposed to simulate the integral lifting process of steel structures. First, in order to verify the validity of the VFIFE method, taking the steel gallery between the integrated building and the attached building of Nanjing M obile Communication Buildings for example, the static analysis was carried out and the corresponding results were compared with the results achieved by the traditional finite element method. Then, according to the characteristics of dynamic construction of steel structure integral lifting, the tension cable element was employed to simulate the behavior of dynamic construction. The VFIFE method avoids the iterative solution of the stiffness matrix and the singularity problems. Therefore, it is simple to simulate the complete process of steel structure lifting construction.Finally, by using the VFIFE, the displacement and internal force time history curves of the steel structures under different lifting speeds are obtained. The results show that the lifting speed has influence on the lifting force, the internal force, and the displacement of the structure. In the case of normal lifting speed, the dynamic magnification factor of 1. 5 is safe and reasonable for practical application.
文摘Time and cost are two of the most important factors to consider in each construction project. In order to maximize performance, both the client and the contractor will work to optimize both the duration of the project and its cost. We show a model of linear entire mixed programming to solve the considered problem. The aim is to minimize the project total time, by means of the assignment of equipments of work to the different production lines of the activities to realizing. The fundamental beginning is to support the same production （rate of production in meters/day of the activity in view of the equipment of work） for tbe different equipments to achieve the maximum efficiency in each period of time. With the limited availability of resources, the work must be continuous and the period of time between operations and final must be kept. However, this paper also presents the bibliographical study on methodologies of the optimization of construction processes in response to the two objectives： time and cost. This will consider the use of recta-heuristic techniques, such as population based algorithms.
