Construction Planners Research Articles

The Impact of Flow Patterns Due to the Cold Lahar Flooding of Mount Semeru on the Collapse of the Bridge Connecting Malang District and Lumajang District

The flow patterns that occur in rivers as a result of falling cold lava often cause damage here and there. This incident cannot be separated from the large volume of water mixed with material that crosses the open channel which is caused by input water supply or water supply from river reservoirs crossed by cold lava. by water researchers for water mixed with volcanic eruption material suspended above. The event of water flowing through a river is influenced by the presence of the surface profile of the river bed and the various widths of the river that occur. If a volume with a certain viscosity is given, a thick flow will be formed that can be seen on the surface of the river, while that which is not visible to the naked eye above the water surface is called thick viscosity. If the runoff of cold lava material that occurs in the channel is not measured, it will result in wild jumps. The wild and viscous jumping structure that has been arranged can be observed as to how the flow pattern occurs. To avoid not detecting the flow pattern, water measuring structures are needed, one of which is a threshold with openings below or what is known as flow above the threshold along with existing bridge buildings around it. This sluice gate is easy to operate manually. The need for water operations with excess water availability is not an easy thing to calculate, because of the influence of depth and jumps that occur around the bridge, hydraulic jump patterns often ignore this measurability, this will be an obstacle if there is a large supply of cold lava. mixed with rainwater during peak conditions in the drainage process. Observations of this completion need to be proven by carrying out model tests using a tool known as the Threshold which produces a water jump along with the material. This requires further investigation for research in the model channel. For modeling thresholds and bridges connecting between plains, this tool provides instruments and many threshold treatments as well as regulating pressurized water with a pump at a certain flow rate in a measurable manner. To analyze the height of building damage, determine the flow pattern, speed by observation, test results with valve openings on certain pumps, researchers tested and measured the position of cold lava deposits one by one, the position of the slope of the river in certain sections, starting with an opening of 0.5; 0.75, read the instrument, move the threshold position from a bridge distance of 20 cm, 40 cm, to the furthest distance of 240 cm. Make graphs of test results for the threshold of the bridge opening transfer tool by testing the tool and opening 3 times for each pump opening, recording, mapping the depth values, jump length and travel time of the instrument on the test tool. Recommend the results of the analysis of the Threshold and Bridge tests to provide information to bridge construction planners that the test results with various threshold positions in certain conditions have the value of the Glidik II bridge collapse, the jump with the travel time of the speed of passing cold lava. Next, the bridge is determined and the next threshold can be used to determine how severe the damage is to the river. This research is laboratory research with threshold and bridge models. The target of this output is a journal article resulting from a simulation of determining the flow pattern that occurs in the channel by shifting the position of the threshold relative to the location of the bridge from the channel model with various diameter sizes of the model material, the results of which are in the form of a table and graphed on the part modeled in the water laboratory, especially flow with sediment and cold lava material. The results of this section were observed up to the collapse of the bridge at a depth of 4.5 cm with an opening of ½ second to 37 (on the model scale) observed or a depth of 45 meters (on the empirical scale). to then be written in the form of an article to be included in an international journal.

Modeling of GPM and LPM in Centrifugal Pump for Obtaining Hydraulic Flow Pattern Types

The types of hydraulic flow patterns in laboratory testing through the use of physical modeling tools often encounter several challenges when confronted with the use of empirical model scales, namely, the issue of scale. Water structures in the horizontal dimension do not experience highly complex issues because there are many measuring instruments available, whether self-made, home industry-produced, or industrial-grade. The presence of water volume in storage can only be tested at a clear scale, especially when it is already within a water tower (reservoir) installation with a specific height. Determining the need for water storage in a water tower is not an easy task to calculate due to differences in height, diameter, and storage capacity. Hydraulic experts often overlook these differences, which can become a problem when there is a demand for the volume of water during peak flow conditions. The solution to this issue needs to be verified by conducting model tests using a device known as the Centrifugal Pump, which has not been previously explored for laboratory research. GPM LPM model tests on this device make use of instruments and numerous pressure measuring tools supplied with pressurized water by a pump at specific, measurable volumes. To analyze the flow rate, flow coefficients, flow velocity, Reynolds number, Froude number, and test results with various speeds (speed meter), researchers test and measure the capacity of GPM LPM for each valve opening, starting with openings of 0.5, 0.75, 1.00, reading the instruments, shifting the speed from 1, 2, 3, 4, up to the highest speed, which is 12. A graph is created to display the test results of the GPM LPM speed booster device, which contains an electric motor. The test is conducted with three repetitions for each valve opening, and the speed and travel time values from the instruments on the test device are recorded and mapped. Subsequently, the analysis results of the GPM LPM test are recommended to provide information to construction planners of water structures. These results show that, under specific conditions of different speeds and valve openings, there are variations in the volume and travel time values. This information can be applied to determine the required storage capacity for each water tower building with a hydraulic flow pattern based on Reynolds number (Re) and Froude number (Fr).

Comparative Analysis of Bearing Capacity of Pile Foundation Using Van Der Ween, Philipponnat, and Meyerhof Methods

Soil has different characteristics so that it becomes a lot of problems in Civil Engineering construction, especially in foundation planning, it must be done carefully and use several methods as a comparison. This research is to compare the three methods of calculating the bearing capacity of bored pile foundations: Van Der Ween, Phillipponnat, and Meyerhof. The selection of an apposite method in bearing capacity analysis is important to confirm the safety of the building structure. The Van Der Ween Method is a more modern and detailed approach compared to the Meyerhof Method, it takes into account the negative impact of the lateral deformation of the pile, which improves the accuracy of its calculation. The Philipponnat Method is a method that combines aspects of both the Meyerhof Method and the Van der Ween Method, it considers load characteristics and soil properties like Meyerhof, while also accounting for lateral deflection of the piles like Van der Ween. The results show that each method has advantages and disadvantages in determining the bearing capacity of bored pile foundations. Analysis revealed factors such as pile diameter, soil depth, and maximum applied load affect the accuracy of the three methods. This research provides important insights for construction planners in selecting a suitable method for bored pile foundation bearing capacity analysis. It is recommended that soil characteristics and pile geometry be considered before selecting the most appropriate calculation method. This research can be extended by considering other methods and conducting validation through experimental analysis.

Assessment of the Significance of Identified Attributes Affecting the Rebar-Fixing Productivity Using Multiple Regression

Reinforced concrete structures are an inherent part of the construction sector. Every in situ reinforced concrete structure cardinally involves rebar-fixing works, which entails activities like transporting, marking, laying, and tying the rebar for the components under construction. Rebar-fixing absorbs a significant number of man-hours during the operation. Therefore, productivity of rebar fixers is a critical concern in construction. Several attributes influence rebar-fixing productivity. Former studies have investigated the impact of the attributes separately and predominantly using qualitative data. A few studies have assessed rebar productivity quantitatively but ignored the effects of some crucial parameters, such as congestion, crew composition, and construction delays. Moreover, studies are limited to account for all time proportions like productive, semiproductive, and nonproductive while assessing rebar productivity. Therefore, this study addresses the aforementioned research gaps by assessing the impact of diverse attributes using direct measures of rebar-fixing productivity and its attributes. Initially, hypotheses were developed to determine the influence of eight attributes identified in this study on rebar-fixing productivity. Next, the data were recorded from one large construction project in Gujarat, India. The work sampling approach was adopted for the productivity assessment of rebar fixers at the project site to evaluate each time proportion. Furthermore, the stepwise regression analysis was performed on the data set to examine the hypotheses. Results indicate that attributes such as quantity of reinforcement, characteristic rebar diameter, and congestion have a significant positive impact on rebar-fixing productivity, whereas work duration has a significant negative impact on it. The outcomes of this research can aid the site management, structural engineers, and construction planners in decision-making to enhance the productivity of rebar fixers, thereby adhering to the budget and schedule constraints of the project.

Optimizing the Planning of Airport Airside Expansion Projects to Minimize Air Traffic Disruptions and Construction Cost

This paper presents the development of a novel multiobjective model for optimizing the planning of airport airside expansion projects that provides the capability of minimizing both airport operations disruption cost and total construction cost. The model computations are performed in four main modules: (1) a simulation module that calculates and quantifies the impact of airport construction activities on airport operations, (2) a multiobjective genetic algorithms optimization module that identifies an optimal schedule for airport airside expansion projects, (3) a scheduling module that calculates the start and finish times of each construction activity, and (4) a cost module that computes the total cost of construction-related disruptions in airport operations and the total construction cost. A real-life case study of an airport airside expansion project is analyzed to illustrate the use of the model and highlight its original contributions to the body of knowledge including its novel methodologies for (1) quantifying and minimizing the impact of construction activities on airport operations, (2) analyzing and minimizing the impact of air traffic data and airport operations on total construction cost, and (3) generating a set of optimal construction plans including optimal project start time, activities start time, and weekly and daily work plans for all activities. The results of the case study clearly illustrate the original contributions of the developed model and its novel capabilities that are expected to support airport and construction planners in their efforts to improve the cost-effectiveness and functional performance of airports during airside expansion projects.

Civil Study Club : Pelatihan Software SAP2000 pada Mahasiswa Teknik Sipil Universitas Teuku Umar

The development of sustainable construction technology requires construction planners to continue to follow technological innovations in the completion of infrastructure projects. One of the basic principles of construction technology that must be carried out is to apply construction technology based on industry 5.0. Therefore, this service aims to provide socialization and training to Teuku Umar University students to be able to use applications that can be used to facilitate the field of construction in the world of technology, namely SAP2000. This service is carried out offline via zoom. The method in this service is that each participant is trained to use the SAP2000 software to master the tools in the software, so that they can model bridges with steel materials, and can produce good designs for construction by providing material, questions and answers, and discussions. The result of this service is the existence of civil study club activities: socialization and training of the SAP2000 software, in the future it is expected to create superior human resources who can master the use of SAP2000 in completing infrastructure construction technology in the world of construction.

Damping transformation modeling on wheel suspension using pneumatic cylinder thrust force as a substitute for vehicle weight

This study aims to produce a vertical dynamic load transformation model, FDV of medium weight vehicles that burden the road structure, the form of suspension work characteristics on vehicle wheels that experience disturbances and vertical loading, and the relationship between vehicle vertical dynamic loads and road structure strength, FA0 in the form of a dimensionless parameter. The experiment was carried out at the Pneumatic and Hydraulics Laboratory of the State Polytechnic of Ujung Pandang using pneumatic actuators as a substitute for vehicle weight. The dynamic load fluctuation of the medium weight category vehicle is equivalent to a pressurized air setting from 1 bar to 6 bar which puts a direct load on the suspension system on the vehicle’s wheels. The deviation, Y (cm) that occurs when there is compression on the Spring and Shock Absorber can be measured using a distance sensor, while the vertical dynamic load, FDV which burdens the road surface using a Load Cell. The data were analyzed using the vehicle dynamic load equation with pressure variable, P2 (bar), spring constant, k2 and damping fluid coefficient, c. A mathematical study of the vibration characteristics of the vehicle suspension was obtained using the Mat Lab program. The results showed that the vibration characteristics of the vehicle body experienced an overshot at a deviation of Y is 0.534 m for 0.131 seconds. The role of the shock absorber in the suspension mechanism can reduce 26.43 % of the vertical dynamic load FDV (N), and in the time interval, t is 3 seconds with acceleration deviation, is 0.25 m/s2 begins to feel comfortable. The relationship between vehicle dynamic load, FDV and road structure strength, FA0 is 0.0178. The data from the comparative analysis is then recommended as a consideration for road construction planners to determine the strength and service life of the road.

STUDI KOMPARASI PEDOMAN DESAIN SEBAGAI REFERENSI INOVASI DAN DESAIN BENDUNGAN BETON GRAVITY

Concrete gravity dams continued to develop in Indonesia even though the population is still smaller than embankment dams. Until 2021 there consist of 16 concrete gravity dams or about 7% of all dams in Indonesia. The utilization of concrete gravity dams in Indonesia is 75% for hydropower or as many as 12 dams. Concrete gravity dam is a high-risk structure so the design of concrete gravity dams must be referred to the guidelines where applicable in Indonesia and internationally with approval from Dam Safety Organization. In Indonesia, the construction of concrete gravity dams cannot be separated from the participation of design consultants from developed countries such as the UK, Japan, US, Canada, Korea, and China. Indonesian Water Resource Guidelines 2009 is formal reference that must be adhered to by all design and construction planners in Indonesia, so that designs that refer to the guidelines and manuals from foreign countries must go through a comparison and evaluation process to meet the design acceptance criteria in accordance with the Indonesian Water Resource Guidelines 2009. Comparison processes include load conditions, design concepts, seismic analysis methods, stability and stress analysis methods, and stability and stress acceptance criteria. As a results of comparison, we can get information that the Indonesian Water Resource Guidelines 2009 apply stability and stress acceptance criteria more conservative. As consequence, the investment cost for the construction of concrete gravity dams in Indonesia is becoming more expensive.Keywords: dams, concrete gravity, guidelines, comparation, stability.

Landslide hazard assessment using analytic hierarchy process (AHP): A case study of National Highway 5 in India

Slope failure along highways is a crucial problem in hilly regions. Landslide hazard maps are very efficient and effective tools for planning and management of landslide disasters. Aim of this study is to prepare a landslide hazard map along national highway 5 (197.600–283.200 Km) using analytic hierarchy process (AHP) model. The different causative factors of landslides considered in this study are slope, aspect, curvature, relative relief, fault density, drainage density, geology, topographic wetness index (TWI), distance from road and lithology. The causative factors are divided into sub-factors and weightage are assigned according to analytic hierarchy process (AHP). The causative factor layers are overlaid using weighted linear combination (WLC) technique and a landslide hazard map is prepared. A landslide inventory of 215 landslides is used for validation of the landslide hazard map. The map shows a prediction rate of 0.825 on area under curve (AUC) technique. The study can be used by the construction planners and decision makers.

Quantification of Particulate Emission from Construction Activities Using Discrete-Event Simulation

Construction activities generate a significant number of airborne pollutants. Particulate matter (PM) is one of the important emissions arising throughout construction, especially in large-scale projects due to the utilization of heavy-duty equipment. Nevertheless, there is no competent approach that is capable of quantifying PM emissions from construction equipment operations at the pre-planning stage. Therefore, the development of a sufficiently accurate and simple quantification model is pressingly needed as the first step to help construction planners in identifying potential mitigation opportunities toward sustainable construction. This paper introduces a PM emission estimation model in an integrated application with a discrete-event simulation (DES) technique, namely EZStrobe. The model is developed with the aim of improving the current body of knowledge in the aspects of simplicity and practicality to address the restriction of input data availability in the initial phase of construction projects. A case study of a real highway project in Thailand is used to demonstrate the use and performance of the developed model in evaluating the environmental impacts in terms of diesel exhaust emissions. The findings identify critical construction activities and factors potentially affecting the environment. This approach enables construction planners to obtain a holistic, sustainable viewpoint in efficiently managing existing construction resources.

Cost-oriented analysis of fibre reinforced concrete column-supported flat slabs construction

Fibre reinforced concrete (FRC) is increasingly being used in elements with high structural responsibility, the constructed FRC column-supported flat slabs (CSFSs, hereinafter) with partial or even total substitution of reinforcing steel bars being a supporting evidence for that statement. These pioneer experiences provide encouraging results with respect to resource optimization and construction time reduction without jeopardising the structural reliability. Despite such promising achievements, the use of FRC in CSFSs is still limited in the building sector. To provide an additional impulse for the use of FRC, a comprehensive comparison between FRC and traditional reinforced concrete (RC) technologies for CSFSs in terms of execution procedure and overall costs is needed. With this in mind, an industrial-oriented study was carried out with the main objective of elaborating a simplified method for the preliminary comparison of RC and FRC solutions. This method permits to assess the major amount of the required reinforcement (flexural reinforcement) followed by an evaluation of the time saving effect due to the partial or total substitution of reinforcing steel bars by fibres. For this purpose and for the sake of generalization, several databases were examined and 33 interviews with experts on in situ construction were conducted so that a wide range of productivity rates and other particularities could be identified. Based on the proposed method, a case study was analysed in order to indicate the potential direct costs (materials + labour) for a number of RC and FRC solutions using data from the examined databases and conducted interviews. The results reflect an increment of direct costs for both fibre and hybrid (fibre + reinforcing steel bars, HFRC) solutions; however, these increment can be compensated by the reduction of the construction period and, as a consequence, time-dependent costs (i.e., preliminaries, equipment costs, overheads, and finance costs). The outcomes of this research are meant to provide support to designers and construction planners with regard to the suitability of using FRC for CSFSs.

Stochastic scheduling optimization of repetitive construction projects to minimize project duration and cost

Considering risk and uncertainty during the scheduling optimization of repetitive construction projects is a challenging task. This article presents the development of a novel multi-objective stochastic scheduling optimization model for minimizing the expected project duration and cost of repetitive construction projects. The developed model integrated Monte Carlo simulation with a multi-objective genetic algorithm to: (1) consider uncertainties associated with the production rates of the construction crews; and (2) identify an optimal crew formation and crew deployment date for each activity that minimize the project duration and cost. The performance of the developed model was analyzed using a real-life case study that highlighted the novel model capabilities in generating a set of optimal trade-off solutions between expected project duration and cost while considering all uncertainties in crew production rates. These novel capabilities of the developed model enable construction planners to identify and implement an optimal resource utilization plan that account for inherent project risks.

Minimizing transportation cost of prefabricated modules in modular construction projects

PurposeThe objective of this research study is to formulate and develop a novel optimization model that enables planners of modular construction to minimize the total transportation and storage costs of prefabricated modules in modular construction projects.Design/methodology/approachThe model is developed by identifying relevant decision variables, formulating an objective function capable of minimizing the total transportation and storage costs and modelling relevant constraints. The model is implemented by providing all relevant planner-specified data and performing the model optimization computations using mixed-integer programming to generate the optimal solution.FindingsA case study of hybrid modular construction of a healthcare facility is used to evaluate the model performance and demonstrate its capabilities in minimizing the total transportation and onsite storage costs of building prefabricated modules.Research limitations/implicationsThe model can be most effective in optimizing transportation for prefabricated modules with rectangular shapes and might be less effective for modules with irregular shapes. Further research is needed to consider the shape of onsite storage area and its module arrangement.Practical implicationsThe developed model supports construction planners in improving the cost effectiveness of modular construction projects by optimizing the transportation of prefabricated modules from factories to construction sites.Originality/valueThe original contributions of this research is selecting an optimal module truck assignment from a feasible set of trucks, identifying an optimal delivery day of each module as well as its location and orientation on the assigned truck and complying with relevant constraints including the non-overlap of modules on each truck, shipment weight distribution and aerodynamic drag reduction.

Critical considerations on tower crane layout planning for high-rise modular integrated construction

PurposeModular integrated construction (MiC) is the most advanced off-site construction technology. However, the application of MiC for high-rise buildings is still limited and challenging. One critical issue is tower crane layout planning (TCLP) to guarantee safe and efficient multiple crane-lifts for module installation, which, however, has been insufficiently explored. For filling this knowledge gap, this paper aims to systematically explore the critical considerations on TCLP for high-rise MiC to support contractors in determining the optimal crane layout plan.Design/methodology/approachThis study employed a multimethod strategy. First, previous studies on TCLP and critical features of MiC were reviewed to develop a conceptual model of TCLP considerations. Second, expert interviews with 15 construction planners were conducted to identify the critical TCLP considerations for high-rise MiC. Third, a multicase study with three high-rise MiC projects was undertaken to demonstrate and verify the identified considerations.FindingsThe paper characterises critical considerations on TCLP as performance criteria and influencing factors and identifies 7 critical performance criteria and 25 influencing factors for high-rise MiC. Specifically, the features of MiC (e.g. various modularised layout design, heavyweight and large size of modules) were found to significantly affect the crane layout performance (i.e. technical feasibility, safety and economic efficiency).Originality/valueThe paper is the first-of-its-kind study on crane layout planning for high-rise modular buildings, which contributes a two-stage multicriteria decision-making framework integrated with systematic TCLP considerations. The findings should help contractors determine safe and efficient tower crane layout plans for high-rise MiC projects.

An overview of seismic ground response methods over the world and their applications in Vietnam

The estimation of the impact of earthquakes on buildings and mega structures in large urban areas is of extremely importance. That is why it always gets attentions from construction planners and policy makers who are concerned about construction rules. When earthquake occurs, the vibration is transferred to sites. Although the vibration intensity is at first not too strong, the motion probably becomes stronger and lasts longer under special conditions of the local site. Two famous examples for these effects occurred in Mexico City in 1985 and in Taiwan in 1999. There are a number of approaches to this problem, such as evaluations based on seismic field observations, the microtremor method, the method using the weak motion data, the method using the strong motion data, the one-dimensional wave propagation method or the three dimensional wave propagation method with simulation etc. In this paper, we will give an overview and discuss about the advantages and the disadvantages of the methods that have been commonly applied in the world. We also present the application of these methods in studies carried out in Vietnam in general and in particular, in Hanoi city. We found that the studies for Hanoi city were mainly carried out in the western areas of Hanoi and a few positions in the urban districts. In addition, the authors only gave comments about and assessments of the shear wave velocity, and classified the ground type without a detailed map of local site effects for the entire area of Hanoi. In order to obtain a full site effects evaluation for Hanoi city, future studies should focus on the application of 1D analysis for the central area of Hanoi city and combining 1D analysis with 2D or 3D to give a better picture about the impact of local site effects. This hybrid approach is necessary in order to compare and verify the data obtained by the empirical and the analytical methods. On the other hand, many problems need to be addressed, for instance, the construction of a detailed 3D geological model for Hanoi, the calculation of the dominant periods and the amplification of the local soil conditions for the urban areas.

Geotechnical Property Modeling and Construction Safety Zoning Based on GIS and BIM Integration

The increase in population and urbanization needs attention towards intense construction activities to meet the social and economic needs. Soil excavation is a primary step in every construction project that needs proper surface and subsurface information modeling since it is vulnerable to construction hazards. Geographic information system (GIS) provides significant information about the existing contextual surface information while building information modeling (BIM) gives information about the asset in a great detail that has been integrated into the construction industry for many applications. However, the integration of BIM and GIS for the subsurface geotechnical property modeling and classification into zones has been rarely explored. This paper presents the integration of BIM and GIS for modeling geotechnical properties and safe construction zones based on soil type. The use of open standard IFC classes such as IfcBorehole, IfcGeoslice, and IfcGeomodel enhances the collaboration and allows the exchange of geotechnical information among different stakeholders. The method has been applied to the in-situ and laboratory test dataset of the Peshawar, region, to validate the proof of concept. The results demonstrate that the proposed method successfully integrates BIM and GIS providing a three-dimensional surface and subsurface model. The 3D digital geotechnical model has excellent potential to provide information about soil type, properties, depth, and volume of each available soil layer that can be used by construction planners and managers to identify best construction practices and plan for safe construction.

The Tripartite Dynamic Relationship between Poverty, Unemployment and Construction Sector: Empirical Evidence from Nigeria

Abstract The increasing rate of poverty and unemployment in Nigeria has necessitated further efforts towards alternative means of reducing the trend, outside the government’s microeconomic mechanisms. As a sector with multiplier effects on other sectors of economy through its numerous activities, the construction sector is expected to reduce both poverty and unemployment. This study, therefore, examined the relationships between construction sector variables, poverty and unemployment rates in Nigeria. Using socio-economic data published by the Central Bank of Nigeria, National Bureau of Statistics, United Nations Development Program and World Bank from 1981-2019, the study deployed an Autoregressive Distributed Lag (ARDL) approach to analyze the relationships between construction sector variables, poverty, and unemployment rates. It also used Granger causality test to determine the direction of causation between the variables under investigation. The results showed that there are both long-run and short-run dynamic relationships between poverty rate and construction sector variables (F-stat. (3.93) > upper (3.67) and lower (2.79)) bounds. It showed that no long-run balanced relationship exists between the unemployment rate and construction sector variables (F-stat. (2.01) < lower (2.79) and upper (3.67)) bounds. The result further revealed that there are significant and positive linear correlations between construction sector variables, poverty, and unemployment rates; except between construction output and poverty rate, where an insignificant linear relation was established. Nevertheless, the relationships could not result to direct causal effect, except a unidirectional Granger causal relationship that flows from government capital expenditure to construction service recurrent expenditure and construction output, and from construction service recurrent expenditure to construction output. Consequently, the study suggested that construction sector expenditure and output should be directed towards poverty and unemployment reduction. This could be done through the diversification and integration of all construction sub-sectors, particularly the private sector into the nation’s economic equation. Thus, this study would direct the paths of policy makers and construction planners towards the right construction policies and plans that would lead to reduction in unemployment and poverty rates with a long-term economic transformation in Nigeria.

Optimizing the modularization of floor plans in modular construction projects

This paper presents an optimization model that enables construction planners to generate and analyze optimal tradeoffs between minimizing the total cost of modular construction projects and maximizing the functional performance of the floor plan. The model is developed in three main stages that are designed to formulate the model decision variables, objective function, and relevant constraints; implement the optimization computations using linear programming; and evaluate the model performance using a case study of a modular construction project of an office building. The results of the case study highlight the original contributions of the model to theory and its impact on practice. First, the model contributions to theory include its novel capabilities of quantifying the impact of room widths and lengths on the total modular construction cost and floor plan functional performance, identifying an optimal width and length for each room in modular construction projects from a range of feasible alternatives, and generating optimal tradeoffs between the two conflicting objectives of minimizing modular construction cost and maximizing floor plan performance. Second, the results of the case study highlight the impact of the model on practice and its ability to provide planners with much-needed support in optimizing the layout of modular construction projects in order to maximize floor plan functional performance while minimizing the total modular construction cost including its fabrication, transportation, assembly, and structural frame costs.

The nexus of transformational leadership, compensation and knowledge management towards employee performance: mediation role of work motivation

This research aimed to analyze the nexus of transformational leadership (TL), compensation (CM), and knowledge management (KM) on employee performance (EP) through work motivation (WM) on engineering consulting companies in Capital Region of Jakarta. This was a causality research which used survey approach. The analysis unit of this research was some engineering companies represented by the experts of construction planners. They had high qualification and they were the members of National Association of Indonesian Consultant (Inkindo) in Capital Region of Jakarta, Indonesia. The target sample of this research was consulting company organizations represented by permanent experts or skilled manpower who worked in construction planning services.  The data collection of this research was primary and secondary by using structural equation modeling with partial least squares method. The total respondent of this research was 106 who were the employees from selected engineering consulting companies in Capital Region of Jakarta. TL had a significant effect towards EP through work motivation. CM had a significant effect towards EP through WM. Lastly KM had a significant effect towards EP through WM. The importance of this research was taken from its context which was conducted in Capital Region of Jakarta, Indonesia. Moreover, this was one of initial efforts to indicate EP by considering TL, CM, and KM and to observe the use of EP for engineering consulting companies in Indonesia. The findings of this research could serve several inputs for organizations in developing the practices between WM dimension and KM expansion among consulting engineering companies in Capital Regional of Jakarta, Indonesia.  JEL Classification: D23, J30.

Optimizing the prefabrication finishing level in modular construction

Prefabricated modules in modular construction projects can have a wide range of finishing levels that range from partially completed with only structural frame to fully completed with all structural, wall, mechanical, electrical, finishing and furnishing components. A higher module finishing level increases the offsite fabrication and transportation cost and decreases onsite assembly cost and duration while a lower finishing level produces the opposite results. This paper presents an optimization model that enables construction planners to identify an optimal finishing level for prefabricated modules to minimize the total cost of modular construction projects that includes all offsite fabrication, transportation, and onsite assembly costs. A case study of a modular construction project for a healthcare facility was analyzed to illustrate the use of the model and evaluate its performance. The results of this analysis highlight the original capabilities of the model in minimizing the total cost of modular construction projects by identifying an optimal finishing level for each module type in the project from a set of feasible alternatives with varying building components, weights, and cost rates.