Reduce Construction Costs Research Articles

ADDITIVE TECHNOLOGIES IN CONSTRUCTION: TECHNICAL, ECONOMIC AND MANAGEMENT ANALYSIS

The study is devoted to a comprehensive analysis of the introduction of additive technologies into modern construction production, revealing the technical, economic, and managerial aspects of concrete 3D-printing of architectural structures. The work systematically analyzes the evolution of additive manufacturing technologies and identifies the main structural types of 3D-printers (an additive machine for layer-by-layer construction of objects), including portal, robotic, mobile, and hybrid systems. A detailed study of the technological parameters of concrete 3D-printing with concrete mixtures is presented, in particular, optimal printing speed modes, layer parameters, criteria for shaping and quality of building structures. A comparative analysis of the technological capabilities of leading world equipment manufacturers, such as ICON, COBOD International, Apis Cor, and WinSun, is conducted. The economic analysis demonstrates significant advantages of additive technologies: reduction of construction time by 2-6 times, reduction of construction cost by 20-35%, and increase in the load-bearing capacity of structures. The study comprehensively explores the structure of capital and operational expenses associated with technology implementation. Special emphasis is placed on the management aspects of introducing additive technologies, highlighting the critical need for an interdisciplinary approach and knowledge integration across architecture, engineering, management, and computer modeling. The study determines the prospects for the development of concrete 3D-printing technology in the construction industry and outlines the main directions of further scientific research and practical implementation of innovative solutions. This study was developed between the Department of "Integrated Technologies of Mechanical Engineering" named after M. Semko of NTU "KhPI" and "Geopolimer" LTD to implement innovative technologies in the construction industry.

Optimization of water distribution networks using simulated annealing (SA) with variable neighbourhood search (VNS): a case study in the city of Malard

ABSTRACT Water distribution networks (WDNs) are essential for modern cities, as effective design can reduce construction costs and ensure reliable service. As cities expand, optimizing these large networks becomes increasingly complex. In this work, we introduce a novel approach by combining simulated annealing (SA) with variable neighbourhood search (VNS) into a single heuristic algorithm for WDN optimization, marking the first use of the SA-VNS method in this context. Additionally, we apply Taguchi's design of experiments (DOE) to tune the parameters of the SA-VNS algorithm specifically for water networks. We tested our new algorithm on four standard benchmark networks and a real-world WDN, including a case study of a large city. Our results demonstrate that the SA-VNS algorithm outperforms existing methods in terms of cost, speed, and overall effectiveness, making this research a significant advancement in both heuristic methods and parameter-tuning techniques for WDN optimization.

Risk−Based Cost−Benefit Optimization Design for Steel Frame Structures to Resist Progressive Collapse

The design of structures to resist progressive collapse primarily focuses on enhancing structural safety and robustness. However, given the low probability of accidental events, such designs often lead to a negative cost–benefit. To address this problem, this paper uses risk analysis to optimize the progressive collapse resistance design of steel frame structures. The elements’ cross-section design for the progressive collapse resistance of steel frame structures is optimized using genetic algorithms and SAP2000 23, which identify the structural model with the minimum robustness index while ensuring safety. The results show that the risk-based robustness index can effectively assess the cost of progressive collapse design. More importantly, the optimization model can rapidly identify the most cost-effective structural design solution that complies with progressive collapse resistance guidelines, enhancing the simplicity and usability of the structure design optimization process. Additionally, the integration of the SAP2000 API with Python 3.8 automation streamlines the parameterization process, minimizes manual errors, and enhances the precision and efficiency of the structural design optimization. Finally, the model’s effectiveness is validated through a case study, where the refined single-frame structure shows a reduction in initial construction and collapse-related costs by 2.4% and 9.1%, respectively. Meanwhile, the three-dimensional frame shows a 2.9% rise in initial costs but a 13.5% decrease in total collapse-resistant design costs, illustrating the model’s ability to balance safety with cost-effectiveness.

Research on the optimization of proportions for synchronous grouting material in composite muck during shield tunneling

To tackle the challenge of onsite resource reuse of composite muck, which relies on a shield tunneling section in the case of Nanjing Metro Line 7, this paper examines the effects of component substitution and varying proportions of factors on slurry properties through laboratory tests and multiobjective modeling. From a practical application perspective, the potential of using composite muck as a synchronous grouting material for shield tunneling was explored. In reference to the common mixed strata encountered in shield tunneling construction in the Nanjing area, a general slurry mixing ratio suitable for various mixed strata conditions was derived. The research results indicate the following optimized mixing ratios for the composite muck slurry: a water-to-binder (cement + fly ash) ratio of 0.76, a cement-to-fly ash ratio of 0.53, a binder-to-soil (silty clay + silty fine sand + river sand) ratio of 0.67, a clay (i.e., silty clay)-to-sand (i.e., silty fine sand + river sand) ratio of 0.4, and a substitution ratio (i.e., silty fine sand/silty fine sand + river sand) of 0.2. This slurry is feasible for practical applications and can reduce construction costs by 38.13%. The obtained general mixing ratio for the composite muck slurry, suitable for various mixed stratigraphic conditions, essentially meets onsite construction requirements (the bleeding rate is controlled within a low range of 1.1–3.1%, and the maximum compressive strength reaches up to 6.76 MPa at 28 days), with reasonable costs. It streamlines construction by eliminating the need for onsite screening of muck, allowing for the direct onsite reuse of composite muck in shield tunneling.

COMPARATIVE ANALYSIS OF TECHNICAL, ECONOMIC, WEIGHT, AND SIZE CHARACTERISTICS OF HORIZONTAL AND VERTICAL STEAM GENERATORS FOR 1000 MW NUCLEAR POWER PLANT UNITS

A comparative analysis of the technical characteristics and parameters of horizontal and vertical steam generators for reactorinstallations with water coolant in modern 1000 MW NPP power units has been conducted. It is noted that the peculiarities of thedesign schemes and constructions of steam generators in NPP power units with water coolants are significantly influenced by thestrong dependence between the coolant temperature at the steam generator inlet and the pressure in the reactor circuit. Thedependencies of coolant and working substance temperature changes and the amount of heat transferred in steam generatorelements have been considered. The t-Q diagram of a steam generator with a water coolant featuring a non-boiling economizer,evaporator, and superheater is presented. The parameters of water coolants and working substances in nuclear power plant steamgenerators are provided. The t-Q diagram for steam generators without a superheater section is shown, because in modern 1000MW nuclear power plant units with steam generators which use water as the working substance in the steam-turbine cycle,saturated steam without superheating is used. This is because minor superheating of the steam does not significantly increase theefficiency of the steam-turbine cycle but requires significant complexity in the design of the steam generators. It is noted that thecorrect choice of their structural schemes is crucial in the creation of steam generators with water coolants. It has been proven thatthe characteristics determining the structural schemes of steam generators with water coolants are: the scheme of washing the heatexchange surface with the coolant, the form of the heat exchange surface, the layout of steam generator elements, the principle ofworking substance movement, and others. The technical characteristics of a horizontal-type steam generator for 1000 MW nuclearpower plant units are presented, which have proven to be quite effective in operation. However, their designs and characteristicslimit the potential for further improvement of the technical and economic indicators of nuclear power plants. It is noted thatimproving the technical and economic efficiency of 1000 MW nuclear power plant units while simultaneously reducing capitalcosts for their construction is possible by increasing the unit capacity of powerful vertical-type steam generators installed on them.Compared to horizontal steam generators, vertical steam generators allow for a more rational layout of the primary circuitequipment in the reactor department, thus reducing the volume and cost of construction and installation works. The maindimensions and weight characteristics of possible designs of vertical steam generators for nuclear power plants with VVER-1000reactors are provided. It is concluded that once-through vertical steam generators with spiral wound heat exchange tubes and watercoolant in the first circuit tubes weigh approximately 1.5 to 2 times less than vertical steam generators with natural circulation. It isdetermined that once-through vertical steam generators with a hydraulic scheme involving the movement of the working substancein the tubes and the water coolant in the inter-tube space significantly lag behind once-through vertical steam generators with watercoolant in the tubes in terms of dimensional and weight characteristics and also vertical steam generators with natural circulation interms of weight. It is concluded that for VVER-1000 nuclear power plants, the most promising of all options are vertical once-through steam generators with the movement of the water coolant in spiral wound heat exchanger tube bundles. These steamgenerators occupy approximately four times less area in the reactor department than horizontal ones with the same steamproduction, which significantly reduces construction costs for nuclear power plants.

Optimum Geometry of Double-skin Self-Shading Facade of Classrooms with the Aim of Creating Energy Saving and Visual Comfort in Isfahan Province, Iran

The significant energy consumption in educational spaces worldwide and its environmental impact greatly influence the quality of space, learning levels, and student comfort. Despite offering free school energy costs, developing countries like Iran have not established specific design principles to ensure student comfort. Additionally, the poor design of school building exteriors, such as the common installation of large, unshaded windows in Iranian schools, causes glare issues. The primary objective of this study is to control direct sunlight and increase shading, thereby reducing its impact on energy consumption and enhancing visual comfort. This paper proposes a novel solution that combines a self-shading facade with a double-skin facade for classroom spaces. The study variables, involving the modification of the geometry of the double-skin self-shading facade via DesignBuilder software and the Daysim plugin, were compared to a simple double-layer facade. Based on the results, the optimal scenario for the self-shading double-skin façade with the specifications of a triangular pyramid module shape, ridge position fold 3/2 the module height, cavity depth 7.0, and number of module 2×2 exhibited 40% lower cooling load, 25% lower heating load, and 95% lower lighting load than a simple double-skin facade. At the same time, all scenarios of the new solution provided better visual comfort and daylighting criteria compared to the simple double-skin facade. The modularity and use of indigenous brick materials in the double-skin self-shading facade design reduce construction costs.

Numerical simulations of floating offshore wind turbines with shared mooring under current-only conditions

In recent years, with the continuous development of offshore wind power, reducing construction costs has become one of the key issues. Among them, the mooring system cost accounts for about 20%–30 % of the entire floating offshore wind turbine investment. The concept of shared mooring systems can potentially reduce the cost of floating offshore wind farms (FOWF). In this paper, research is carried out on the dynamic response of an FOWF under representative current conditions of the South China Sea. The comparative analysis focuses on the motion response of a single-spar Floating Offshore Wind Turbine (FOWT)and a dual-spar FOWF. A sensitivity analysis was performed on the length of the shared mooring line. The NREL 5-MW wind turbine with a spar platform is taken as a basis FOWT model for this work. The frequency-domain hydrodynamics is computed based on potential flow theory. The time domain analysis was simulated in a software for marine operations: SIMA(DNV). The viscous effect on the floater is modeled by the drag term in Morison's equation and the hydrodynamic force acting on the mooring line is computed using Morison's equation. Based on the finite element method, the mooring line is defined by a sequence of segments with homogeneous cross-sectional properties. The result shows that with the increase of the current return period, the two platforms move synchronously, and the movement increases almost linearly. Moreover, the motion response of the shared mooring platform is smaller than that of the single mooring platform under the same conditions, especially in the vertical direction. This paper contributes to improved fundamental understanding of shared mooring systems under complex marine environmental loads.

Geotechnical, Mineralogical, Petrographic and Microstructural Characterization of Two Lateritic Gravels from Congo

The recovery of lateritic gravel contributes to the reduction of road construction costs and environmental impact. These materials are of particular interest in road construction because of their abundance, especially in tropical countries, as in the case of Congo. The results obtained on the soils of ʽʽTSANGA and TSIAKIʼʼ show an identical appearance of the two particle size curves, with more fines in the TSANGA sample. Both soils are moderately plastic and their properties predispose them to mechanical treatment (TSIAKI soils) and hydraulic binders (TSANGA soils). The lateritic gravels of TSIAKI can be used as road sub-base for medium traffic while those of TSANGA as sub-base for low traffic. The geotechnical properties of the two samples differ due to the mineralogy, petrography and microstructure which vary from one deposit to another. The SEM microstructure study shows two matrices completely made of kaolinite and the matrix facies are cemented by hematite. X-ray microscopy and SEM allowed the differentiation of goethite and hematite to distinguish the two forms of iron oxides. The TSIAKI soil has a normal iron oxide content (mainly goethite), and has less quartz and kaolinite, which could justify its high CBR index.

Comparative Study on the Prevention and Control Effects of Rockburst Between Hydraulic Fracturing Sections and Blank Sections.

Influenced by various factors such as the complex environment and high key layers in coal mines, hydraulic fracturing technology has gradually become the main means of controlling the hard roof strata to prevent and control rockburst in recent years, which can effectively release the stress on the roof, reduce the intensity of pressure, and ensure the safe and efficient mining of the working face in coal mines. However, the current research on hydraulic fracturing to prevent and control rockburst is mostly limited to optimizing fracturing parameters and monitoring and evaluating fracturing effects, and there are few studies on blank sections, which cannot guarantee the overall prevention and control effect of rockburst, or increase unnecessary construction costs. In this paper, for the directional long borehole staged hydraulic fracturing project, triangular-type blank sections and regular-type blank sections are defined, and the rockburst prevention and control effects of fracturing sections and triangular-type blank sections during fracturing are compared and analyzed by the underground-ground integrated microseismic monitoring technology and transient electromagnetic detection technology, and the rockburst prevention and control effects of fracturing sections and regular-type blank sections during the coal extraction period are compared and analyzed by the underground-ground integrated microseismic monitoring data such as microseismic energy level and frequency as well as the online stress monitoring data. The results show that leaving the triangular-type blank sections can result in reduced construction costs without compromising the effectiveness of rockburst prevention and control. Additionally, the performance of rockburst prevention and control in regular-type blank sections is notably superior to that observed in other working faces without hydraulic fracturing. However, when compared to fracturing sections, the efficacy of rockburst prevention and control in regular-type blank sections remains relatively inferior. Therefore, during the design of fracturing boreholes, it is imperative to strive for maximum coverage of regular-type blank sections. The research findings of this paper comprehensively summarize two prevalent types of blank sections encountered in directional long borehole staged hydraulic fracturing projects. A rigorous comparative analysis is undertaken to evaluate the rockburst prevention and control effects between fractured sections and blank sections. This comparative evaluation serves as a valuable reference for the optimal design of fracturing boreholes, ensuring a balance between achieving effective rockburst prevention and control measures and minimizing economic costs.

Utilization of coalmine overburden-furnace slag and fly ash mixed cement-treated subbase/base course material for sustainable flexible pavements: mechanical performance and environmental impact.

The scarcity of conventional aggregates with tremendous growth in highway construction and the indiscriminate dumping of industrial waste materials in precious landfills has become a huge global concern. This study is aimed at utilizing wastes from various industries, including coalmine overburden (OB) dump, basic oxygen furnace (BOF) slag, and fly ash to produce suitable and sustainable cement-treated subbase/base course layers (CBSB/CTB) for flexible pavement construction. Response surface methodology was used to optimize the composition of the blended material considering unconfined compressive strength (UCS) and Poisson's ratio. Results demonstrated that 50% OB dump, 40% slag, 5% fly ash, and 5% cement achieved a 7-day UCS of 4.84MPa and Poisson's ratio of 0.25, in line with IRC:37-2018 guidelines. X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) analysis confirmed the presence of ettringite crystals, calcium-silicate-hydrate (C-S-H), and calcium-aluminosilicate-hydrate (C-A-S-H) gels which are the source of strength development in the blend. Further, a soaked California bearing ratio (CBR) of 136.08% and flexural strength of 2.06MPa after 7days and 28days of curing, respectively, demonstrates the overall strength of the stabilized waste. Approximately 4% weight loss was observed after wet-dry durability tests, indicating exceptional performance of the optimal blend in inclement weather conditions. Furthermore, the environmental impact of the blended material was studied through a leaching study. Fly ash had a high zinc (Zn) level, while BOF slag showed a rich concentrationof chromium (Cr), manganese (Mn), and iron (Fe) in the acid digestion test. In spite of this, the toxicity characteristics leaching procedure (TCLP) test indicated that the levels of heavy metals that leached from the stabilized material stayed considerably below the permissible limits set forth in Indian Standard, IS:10500 (2012). Finally, cost analysis showed a 51.6% reduction in construction cost with cement-treated industrial wastes instead of granular base/subbase made with conventional aggregates. The study recommends the suitability of the stabilized waste material as an alternate construction material for large-scale field applications, which could encourage the construction of flexible pavements that are environmentally benign, economical, and sustainable.

Physico-mechanical characterization of compressed earth blocks reinforced with waste fibers from calamus rotang: Case of the elastic soil of western region of Cameroon

In order to enhance the value of local materials and contribute to reducing construction costs in Cameroon, rattan waste is used to reinforce compressed earth blocks (CEB). This main work’s objective is the study of the effect of rattan waste on the physical and mechanical properties of CEB. For this, a soil sample taken in the western region of Cameroon, more precisely in Bangangté, was analyzed, the analysis includes the granulometric analysis, the Atterberg limits, and the Proctor test. Then the CEB samples with different rattan waste contents, that is 0%, 2%, 4% and 6%, were developed for a compaction stress of 7.5 MPa. These different samples were characterized through mechanical and physical tests carried out in the laboratory. It appears that the blocks reinforced with 2% of rattan waste have better mechanical characteristics, respectively 0.70 MPa in three-point bending and 3.04 MPa in compression. On the other hand, the presence of rattan wastes has a positive effect on the mechanical behavior of the composite, by increasing its ductility compared to the fragile behavior of the control block, which is observed during crushing. Thus the mechanical properties of CEB improve with the incorporation of rattan waste, which is optimal for a content of 2%. But they increase the material's porosity, and then its sensitivity to water unlike the control CEB.

Knowledge graph-driven mountain railway alignment optimization integrating karst hazard assessment

Karst hazard is a considerable threat that should be considered in railway alignment design for mountainous regions with dense water systems. Nevertheless, alignment design principles in karst regions have not been systematically studied. Moreover, a quantitative karst hazard assessment model is currently lacking for automated alignment optimization. To solve the above problems, based on the analyses of karst inducing factors and hazard representation, the railway alignment design principles in karst regions are summarized through an event tree. A highly-coupled knowledge graph (called KaRAD-KG) modeling method is proposed. Then, a bi-objective alignment optimization model considering railway construction cost and karst hazard (mainly including hazard components of synclinal karst, anticlinal karst and karst depression) is constructed. To solve the optimization model, a knowledge-driven distance transform algorithm incorporating a karst hazard assessment method and a multicriteria tournament decision method is customized. Finally, the application in a real-world case indicates that the proposed method can generate an alignment which reduces construction cost by 3.39 % and karst hazard by 18.73 % compared to the best manually-designed alternative, which verifies the effectiveness of this method for assisting actual railway alignment design in a karst-dense mountainous region.

Comprehensive Analysis of Implementing Robotics in the Indian Construction Industry

Implementing robotics in the Indian construction industry presents a significant opportunity to address longstanding challenges such as labour shortages, project delays, safety concerns, and quality inconsistencies. As India's urbanization accelerates, the demand for faster, safer, and more efficient construction processes is growing. This comprehensive analysis explores the potential benefits, obstacles, and strategies associated with adopting robotics in India’s construction sector. Key drivers include increasing automation trends, government initiatives like "Make in India," and the global shift toward smart infrastructure. However, challenges such as high initial investment, a fragmented industry structure, and the need for skilled operators and technicians could hinder widespread adoption. The analysis also highlights the role of robotics in enhancing productivity, reducing construction costs, and improving worker safety through a cost-benefit analysis, ultimately paving the way for more sustainable and advanced construction methodologies in India.

Sustainable bridge engineering: Cost reduction and durability enhancement in developing nations

This paper explores innovative approaches to sustainable bridge engineering, focusing on cost reduction and durability enhancement in developing nations. Drawing from my successful projects in Uganda and Guinea, where I reduced construction costs by 30% without compromising structural integrity, I will present detailed case studies that highlight the effective application of sustainable materials and techniques. In Uganda, through the use of locally sourced materials and optimized construction processes, I achieved significant cost savings while ensuring long-term durability in rural infrastructure. Similarly, in Guinea, I implemented advanced engineering practices that prioritized resource efficiency, leading to a reduction in project expenses and a strengthened bridge lifespan. The case studies demonstrate how sustainable engineering practices can be tailored to local conditions and still meet global standards for resilient infrastructure. By emphasizing cost-effective materials such as recycled aggregates and low-carbon concrete, and employing techniques such as modular construction and innovative foundation designs, my work offers a blueprint for reducing expenses while enhancing the longevity of infrastructure. The strategies I employed in Uganda and Guinea are adaptable to other developing nations and can be applied globally, including in the U.S., to build durable and sustainable bridges that address both budgetary constraints and environmental considerations. This paper aligns with the broader goals of sustainable infrastructure development by contributing to the global discourse on resource-efficient engineering solutions. The findings support national and international objectives to enhance infrastructure resilience while minimizing environmental impact and construction costs.

An event tree-based distance transform algorithm for simultaneously determining mountain railway alignments and station locations

The concurrent optimization of railway alignments and station locations (RA&SL) is a complex task, especially for the main railway lines in mountainous regions. The intricate coupling constraints between RA and SL are very challenging for the conventional RA&SL search methods, which consider limited solution types to generate an optimized RA&SL solution. To solve this problem, an event tree-based distance transform (ET-DT) algorithm is proposed. The study area is first divided into grid cells, followed by a preprocessing step to identify infeasible areas for station locations. Next, an event tree (ET) is constructed to represent all the possible solution types during the RA&SL design process. Afterward, in the ET-DT method, a total of eight types of RA&SL search operators are integrated to generate diverse RA&SL alternatives. Ultimately, the proposed method is applied to a realistic case with significantly-undulating terrain. Results show that ET-DT generates 2.8 times more solutions than a contemporary DT-based method (PreDT) and further improves solution quality through an 8.7% reduction in construction cost compared to the best manually-designed alignment, while PreDT only achieves a 5.7% reduction.

Seismic isolation strategy via controlled soft first story with innovative multi-stage yielding damper: Experimental and numerical insights

While the presence of a soft story within a building is typically discouraged in structural engineering due to potential vulnerabilities, this research proposes a strategy that incorporates seismic isolation concepts by integrating a soft first story within the structural framework. This approach challenges traditional reluctance by demonstrating the potential benefits of such a configuration. The primary objectives are twofold: firstly, to diminish seismic responses and enhance structural resilience when subjected to earthquake forces, and secondly, to reduce construction costs as compared to conventional passive control methods. The seismic responses assessed and compared in this study encompass story displacements, story drifts, floor accelerations and base shear of the structure. Furthermore, an investigation is conducted into a replaceable or repairable shear fuse that serves as a controller in the Controlled Soft First Story (CSFS) strategy, namely, an innovative Multi-stage Steel Yielding Damper (MSYD). Notably, the numerical analysis of the introduced damper has been carried out, followed by rigorous validation testing under experimental conditions. This study elucidates the implementation of this strategy within the structural framework. The overarching principle behind employing the CSFS results in outcomes akin to those achieved with base isolation techniques. However, it distinguishes itself by significantly mitigating the construction costs around 70% associated with this system when juxtaposed with traditional base isolation systems.

How to combine different types of prefabricated components in a building to reduce construction costs and carbon emissions?

In the context of industrialized construction and carbon emission reduction globally, prefabrication has gained considerable attention. However, most studies cared the carbon emissions and construction costs from the perspective of a whole prefabricated building rather than the prefabricated components. It makes it difficult to understand the role of prefabricated components play and make improvements from the prefabricated components level. To fill this gap, this study proposes a model to optimize the selection and combination of prefabricated components in a building project to simultaneously reduce the construction costs and carbon emissions. Six common component types were considered: shear wall, beam, floor slab, stair, balcony, and air-conditioning slab. Their costs and carbon emissions were quantified when adopting prefabrication and cast-in-situ technologies. To obtain the optimal solution, we developed an improved multi-objective mayfly algorithm (IMOMA), which incorporates enhanced circle chaos mapping and a global best guiding strategy to generate Pareto solution sets. The performance of IMOMA was evaluated using the Zitzler-Deb-Thiele series test functions, demonstrating its advantages in convergence, diversity, and comprehensive performance through metrics such as generation distance, diversity metric Δ, and inverse generational distance. A case study validated the effectiveness of this proposed method, demonstrating an average reduction of 9.05 % in total construction costs and 8.04 % in carbon emissions when compared to the initial scheme. Further study revealed that different prefabrication rates correspond to different optimal components combination schemes, with different trends in the costs and carbon emission curves as the prefabrication rate increases. Additionally, carbon trading policies influence the components combination, with construction costs reduced by 10.88 % at a carbon trading price of 42.80 CNY/t CO2eq. This study provides valuable guidance for general contractors to design optimal component combinations and for governments to promote the sustainable development of prefabricated construction.

Structural evaluation and analysis of existing house renovation into shophouse based on Building Information Modeling

Indonesia's population and economic growth must be supported by adequate facilities and infrastructure, including residences and business premises. Renovating residential houses into shophouses offers an effective way to optimize land use and reduce construction costs. A thorough evaluation of existing structural elements is critical to determining which components can be retained, alongside accurate cost and scheduling assessments to ensure smooth renovation. This research utilizes Building Information Modeling (BIM) to integrate structural, architectural, and MEP work, as well as to streamline scheduling and cost estimation. ETABS is employed for structural design, while Autodesk Revit and Navisworks are used for cost and schedule planning. The assessment follows ASCE 41-17 guidelines to evaluate existing structures, and SNI 1726:2019 and SNI 2847:2019 standards for retrofitting and designing new structures. The evaluation reveals deficiencies in global strength and component ductility, necessitating structural retrofits using concrete jacketing. This study not only addresses the renovation of a residential house into a shophouse but also contributes to broader research in construction. The estimated cost for the structural renovation is Rp. 159,692,607.93, and the duration is projected at 58 days, with 11 days for demolition and 47 days for upper structure construction.

Sustainable architectural solutions for affordable housing in Nigeria: A case study approach

This study provides a critical examination of sustainable architectural solutions as a response to Nigeria's pressing affordable housing crisis. With the country facing rapid urbanization and a significant population increase, there is an urgent demand for housing solutions that are not only cost-effective but also environmentally sustainable. The research adopts a qualitative approach, utilizing a comprehensive review of existing literature, in-depth case studies, and the analysis of current trends to evaluate the feasibility and challenges associated with the implementation of sustainable architectural practices in Nigeria. The findings indicate that locally sourced materials, such as stabilized earth blocks and interlocking bricks, offer a viable means of reducing construction costs while supporting environmental sustainability. Moreover, the integration of renewable energy technologies, particularly solar power, has been identified as a key factor in lowering long-term energy expenses and enhancing the overall resilience of housing developments. Despite these promising strategies, the study identifies significant obstacles to widespread adoption, including financial constraints, a shortage of technical expertise and the gradual decline of traditional building practices. These challenges suggest the need for a holistic approach that includes the adoption of circular economy principles, the exploration of sharing economy models, and the deployment of advanced technologies like artificial intelligence and machine learning to improve the sustainability and affordability of future housing projects. The study emphasizes the importance of continuous professional development, robust policy frameworks and the active participation of all stakeholders to effectively address the housing challenges in Nigeria. These recommendations aim to foster a collaborative effort toward achieving sustainable and affordable housing solutions that meet the evolving needs of the population.

Seismic risk assessment of partially self-centering braced frames designed with multiple-objective-based method

Partially self-centering building structures are promising seismic resilient systems by balancing the reduction of residual deformations, nonstructural loss, and initial construction costs. This research seeks to establish a multiple-objective-design (MOD) approach for partially self-centering buckling restrained braced frames (PSBRBFs) and explore the risks associated with collapse, demolition, and nonstructural damage in PSBRBFs designed using the MOD approach. The peak displacement is set as an objective for achieving the desired collapse-prevention performance while the residual displacement is set as another objective to ensure the expected post-earthquake repairability. To this end, the step-by-step procedures of the MOD method are introduced based on the prediction models of peak and residual displacements of PSBRBFs. 6 building cases are designed with the MOD method. The dynamic results demonstrate that analyzed PSBRBFs can simultaneously achieve the targeted peak and residual displacements, validating the effectiveness of the MOD method. Seismic fragility assessments are conducted utilizing incremental dynamic analyses (IDAs) to investigate the influence of different performance objectives (i.e., different target peak and residual displacements) on the collapse, demolition, and nonstructural damage probabilities of PSBRBFs. And seismic risks of the designed PSBRBFs are investigated with the consideration of earthquake hazard risks. Results indicate that the demolition risks of the designed PSBRBFs are all larger than the corresponding collapse risks. Based on the analysis results, high PID and low RID design targets were recommended for practical applications to achieve excellent performance against demolition and comparable performance in avoiding collapse and nonstructural damage.