Construction and Practice of First-Class Courses on Virtual Simulation Experimental Teaching of Urban Overpasses

Virtual simulation experiment,as a new way to promote the digital transformation of education,has a broad development prospect and application value.The civil engineering experimental volume and space are huge,it has a long construction period,is highly dangerous,and is difficult to experiment with.In order to solve the contradiction between the traditional theory teaching of civil engineering and the engineering training of students,the construction of virtual simulation experimental teaching courses with a high degree of realism,intuition,and accuracy can be used as a useful supplement and innovation of experimental and practical teaching.This paper takes the virtual simulation experimental teaching course of urban overpasses as an example,introduces the necessity and practicability of the course construction,and describes the experimental principle structure of the course,the simulation scene design,the experimental teaching process,the experimental method,etc.The course has achieved good application results,and it has been recognized as the first-class virtual simulation teaching course of the Chongqing Municipal Government,which provides certain references to the construction of the same type of courses in the civil engineering profession.

Experimental Study and Simulation Principles of An Oil-Gas Multiphase Transportation System

Presented is an experimental study on the performance of an oil-gas multiphase transportation system, especially on the multiphase flow patterns, multiphase pumping and multiphase metering of the system. A dynamic simulation analysis is conducted to deduce simulation parameters of the system and similarity criteria under simplified conditions are obtained. The reliability and feasibility of two-phase flow experiment with oil and natural gas simulated by water and air are discussed by using the similarity criteria.

Application of system dynamics for assessment of sustainable performance of construction projects

Sustainable performance is expected to become a major factor when examining the feasibility of a construction project in terms of its life cycle performance. The study on which this paper is based developed a simulation model, using system dy- namics methodology, to assess the sustainable performance of projects. Three major factors are used to examine project sus- tainable performance (PSP): the sustainability of economic development (E), the sustainability of social development (S), and the sustainability of environmental development (En). Sustainable development ability (SDA) was used as a prototype to evaluate the degree of sustainable performance. The simulation software ‘ithink’ was used to help with the application of the model to a real life case. This paper explains and demonstrates the procedures used to develop the model and finally offers an approach for assessing the feasibility of a construction project in terms of its sustainable performance.

3D Finite Element Simulation of Tunnel Boring Machine Construction Processes in Deep Water Conveyance Tunnel

Applying stiffness migration method,a 3D finite element mechanical model is established to simulate the excavation and advance processes.By using 3D nonlinear finite element method,the tunnel boring machine(TBM) excavation process is dynamically simulated to analyze the stress and strain field status of surrounding rock and segment.The maximum tensile stress of segment ring caused by tunnel construction mainly lies in arch bottom and presents zonal distribution.The stress increases slightly and limitedly in the course of excavation.The maximum and minimum displacements of segment,manifesting as zonal distribution,distribute in arch bottom and vault respectively.The displacements slightly increase with the advance of TBM and gradually tend to stability.

The structure and elasticity of phase B silicates under high pressure by first principles simulation

The structures and elasticities of phase B silicates with different water and iron（Fe） content are obtained by firstprinciples simulation to understand the effects of water and Fe on their properties under high pressure.The lattice constants a and b decrease with increasing water content.On the contrary,c increases with increasing water content.On the other hand,the b and c decrease with increasing Fe content while a increases with increasing Fe content.The decrease of M（metal）–O octahedral volume is greater than the decrease of SiO polyhedral volume over the same pressure range.The density,bulk modulus and shear modulus of phase B increase with increasing Fe content and decrease with increasing water content.The compressional wave velocity（Vp） and shear wave velocity（Vs） of phase B decrease with increasing water and Fe content.The comparisons of density and wave velocity between phase B silicate and the Earth typical structure provide the evidence for understanding the formation of the X-discontinuity zone of the mantle.

Simulation analysis of construction process of high rock slope's stabilization

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.

Simulation and experimental study on hydraulic driving fan cooling system for construction machinery working on plateau

Overheating of the engine, the transmission and the hydraulic device is a problem when the construction machinery works on plateau. To solve this problem, we proposed an electro-controlled hydraulic driving fan cooling system (ECHDFCS). The system was applied to a 50-wheel loader. We carried out the coolant temperature simulation using fluid modeling software FLOWMASTER, followed by laboratory experiments and road tests. The results show that ECHDFCS can adjust the cooling capability of the system automatically based on machine heat dissipation requirements. The coolant temperature is consequently remained within an appropriate range. The simulation results are consistent with the experiment results when the experiment is performed on the plain, but are different from the road tests in some investigated parameters on the plateau.

GIS-Based Simulation of Engineering Construction Schedule

For its complexity, engineering construction schedule design is limited by various factors.Simulation-based engineering construction schedule takes critical path method (CPM) network as frame and calls complex cyclic operation network (CYCLONE) simulation model enclosed in advance for its simulation nodes. CYCLONE simulation model takes charge of simulating stochastic duration of activity and efficiency of resources, while CPM model performs project scheduling. This combination avoids the shortcomings of both models. Furthermore, geographic information system (GIS) technique is utilized to visualize the construction processes which are otherwise difficult to be understood by static results described. Application in practical project verifies the feasibility and advantage of the technique.

Research on Teaching Methods of Flight Control Principles

With the rapid development of China’s civil aviation industry,the teaching method of operating knowledge of flight principles has changed greatly,which creates a good implementation environment to improve the safety of civil aviation in our country.At present,the main training content of air route transport pilots in China is basic aviation theory,initial flight training,airline modification,etc.The principles of flight control are an important part of basic aviation theoretical knowledge training,which will involve a large number of flight technology training content,instructors will also be based on the pilot type.Teaching flight control theory and practical knowledge requires relatively high theoretical learning ability of students,and the learning effect of this part of theoretical knowledge will directly affect the quality of subsequent learning,but also directly affect the effectiveness of flight training.This paper focuses on the analysis of the basic concepts of flight control,studies the existing problems in the teaching of flight control principles,summarizes the teaching measures of flight control principles,aiming to provide a reference to teaching personnel.

Fast simulation of flexible multibody dynamics with electric-hydraulic drive system

Hardware in the loop simulation （HILS） has been investigated in the field of the multibody dynamics （MBD）, which combined the MBD simulation with the actual mechanical system. The fast simulation is necessary for the HILS system in order to require the real time simulation. This paper presents a fast simulation technique using the domain decomposition method with the iteration in the flexible multibody system in which flexible linkage system and electro-hydraulic drive system are coupled with each other. C 2013 The Chinese Society of Theoretical and Applied Mechanics.[doi：10.1063/2.1301301]

Dust Diffusion Simulation in the Third Layer Construction of Underground Powerhouse

Under forced ventilation,the dust diffusion of underground powerhouse construction is investigated using a 3D high Reynolds number k-ε model.The interfacial momentum transfers and the wall roughness in the wall function are considered.Ventilation in the third layer of underground powerhouse of Xiangjiaba hydropower station is used as a case.The geometric structure has a decisive effect on the airflow distribution.It is concluded that the dust concentration decreases gradually with the increase of the ventilation time.However,iso-concentration curves have the same tendency after 1 800 s.The dust concentration meets the ventilation and dust-prevention health standard after 2 300 s.The prediction by the present model is confirmed by the experimental measurement by Nakayama.

Exploration on 5E Teaching Principle-based Education for the Object-oriented Software Construction Course

Most current object-oriented programming courses offered by domestic colleges and universities generally focus on the object-oriented programming language itself,i.e.,the programming grammar of the language,but ignore the design pattern.However,design patterns are essential to software engineering because they can solve common problems in software design and improve code reuse,readability,extensibility,and reliability.Our Object-oriented Software Construction Course is creative since it aims at cultivating students’object-oriented thinking as well as basic abilities required to construct high-quality,object-oriented software.Specifically,we exploit the 5E teaching principle during the education of this course,and present the whole pipeline in the paper.We also provide one case of the factory pattern to further demonstrate the implementation of the 5E teaching principle in the course.The effect of the 5E teaching principle has also been demonstrated.

A Study of Challenges and Benefits of Lean Construction(LC)Principles in Omani Construction Industry

There are frequent failures in the project delivery in time and increasing the waste in Oman construction industry.Lean Construction(LC)principles which are lean thinking in design and construction process may be a possible solution.Hence,the paper is aimed on exploring the status of the LC practices and its impact on Omani Construction Industry(OCI).The paper presents barriers,potential benefits,and the measures of suitability and acceptability of LC principles.A quantitative research approach was adopted and research data was collected using an online questionnaire survey in Oman.The data were analysed and results are presented in tables and charts followed by critical discussions.The survey found that onethird of the construction professionals have a good awareness and half of them having a higher level awareness about LC practices.More than one third of the construction organisations are adopting LC principles with a high consensus on the suitability and acceptability,and they recognised that time commitment is necessary for the successful implementation and achieve benefits.The study concludes that the reduction in project delivery time and construction at site waste is the key advantage of implementing LC priciples in design and construction stages in the omani construction industry.

The Application of Principle of Automatic Control in the site Management of Electric Power Construction Enterprise

It is need to establish site project department during the construction of electric power project.The head office should design and build the main structure,continually improve structure of project department,meantime,positively apply principle of automatic control to improve the site management of electric power construction.In this article,the application strategy of principle of automatic control is analyzed focusing on the site work of electric power construction.

Discrete-Event Simulation of Viaduct Construction Methods in Riyadh Metro

The Riyadh metro project is one of the current megaprojects that aim to improve the transit systems in Saudi Arabia.It consists of several metro lines with a total length of 176 km and 85 stations.The viaducts are considered as one of the main construction elements in the metro lines.Four methods for viaducts construction have been used in the Riyadh metro project:precast beam,full span launching method,cast on-site,and segment method(precast segment method and BCM(balanced cantilever method)).The viaducts work consumes a large portion of a project’s time and cost.Furthermore,the competitive nature of the construction industry increases the need to improve the efficiency of construction performance.Accordingly,this paper takes the initial steps toward increasing the efficiency of viaduct construction methods through simulation.Simulation of construction processes provides a systematic tool that can be used for determining the resources,time,and cost of these processes.The simulation processes should focus on the main activities affecting this element’s execution for viaducts construction,such as segment storage,handling,transporting,and installation.This study highlights the viaducts construction methods and develops general discrete-event simulation models for the most commonly used viaducts construction methods in the Riyadh metro using AnyLogic simulation software.The simulation models visualize and capture the interaction between the different activities and resources in a viaduct construction.Consequently,the construction drawbacks can be identified.Furthermore,the simulation model can be manipulated by adding assumptions to develop more efficient construction methods in terms of time and cost in such projects.

Phase equilibrium of Cd_(1-x)Zn_xS alloys studied by first-principles calculations and Monte Carlo simulations

The first-principles calculations based on density functional theory combined with cluster expansion techniques and Monte Carlo （MC） simulations were used to study the phase diagrams of both wurtzite （WZ） and zinc-blende （ZB） Cdl_xZnxS alloys. All formation energies are positive for WZ and ZB Cdl-xZnxS alloys, which means that the Cdl-xZnxS alloys are unstable and have a tendency to phase separation. For WZ and ZB Cdl_xZnxS alloys, the consolute temperatures are 655 K and 604 K, respectively, and they both have an asymmetric miscibility gap. We obtained the spatial distributions of Cd and Zn atoms in WZ and ZB Cd0.sZn0.sS alloys at different temperatures by MC simulations. We found that both WZ and ZB phases of Cdo.sZn0.sS alloy exhibit phase segregation of Cd and Zn atoms at low temperature, which is consistent with the phase diagrams.

Application of BIM + Virtual Simulation Technology in Road Engineering Construction Technology and Organization Course

We focus on the goal of undergraduate talent training,consider the course features of Road Engineering Construction Technology and Organization,analyze the problems existing in the practical teaching of the course,use the advantages of BIM+virtual simulation technology,design a scientific and reasonable practical teaching content of Road Engineering Construction Technology and Organization,and address the contrast between the strong practical aspect of the traditional Road Engineering Construction Technology and Organization course and the lack of practical instruments in hope to improve students’learning autonomy,enhance the quality of practical teaching,achieve the training objectives of the course,and nurture applied technical talents.

Landscape Construction of Wetlands for Wastewater Treatment

By reviewing the development of wetlands used for wastewater treatment both in China and other countries, the definition and classification of wetlands for wastewater treatment are put forward and the guiding principle in the construction of wetlands for wastewater treatment is discussed in this paper. In view of the process of wastewater treatment of the wetlands, appropriate landscape structure of wetlands used for wastewater treatment is proposed which includes three sections as pre-treatment, wetlands and posttreatment. The discussion as well as conclusion is made upon the approaches of landscape construction of these three parts.

Mathematical Model and Simulation of Harmful Invasive Plant Control

Plant invasion refers to the phenomenon that some plants grow too fast due to they are far away from the original living environment or predators, affecting the local environment. With the development of tourism and trade, the harm caused by invasive plants will be more and more serious. Therefore, it is necessary to ex- plore an effective method for controlling plant invasion through qualitative and quan- titative research. In this paper, the models were established for the early and late harmful plant invasion control. The huge computation was completed by the com- puter programming to obtain the optimal solutions of the models. The real meaning of the optimal solution was further discussed. Through numerical simulations and discussion, it could be concluded that the quantitative research on the invasive plant control had a certain application value.

Enlightenment on the Construction of Modern Urban Plazas from Classical Chinese Gardens

Researches on modern urban plazas in China were reviewed,phenomena caused by the shortage of proper theoretical guidance such as blind imitation and fixed forms of urban plazas were pointed out,and it was emphasized that researches on urban plazas with Chinese characteristics should be enhanced.By analyzing features of traditional western plazas and classical Chinese gardens,this study proposed that by combining with their practical functions the construction of modern urban plazas in China should maintain traditional concepts and aesthetic characteristics of Chinese people on the basis of satisfying demands of the public to the best.The enlightenment on the construction of modern urban plazas from classical Chinese gardens was particularly analyzed,the application of garden aesthetics,components,and landscaping methods of classical Chinese gardens were highlighted,and moreover,it was put forward that the relationship between human and human,human and society,human and nature implied in classical Chinese gardens would surely bring profound inspiration to urban plazas.