Case Study of Stormwater Control by Permeable Road in Commercial Centre under Equatorial Climate

This paper describes the investigation into stormwater control measures of a 3,425 m2 commercial centre with 61% of the total areas which were tarred surfaces. Targeting these surfaces, permeable roads of various surface areas from 10 to 34% of the total areas were modelled using Storm Water Management Model version 5.0. Testing the permeable roads for very-short duration storms ranging from 5 to 15 minutes, the study found that the catchment area contributing water for detention purposes played a major role in stormwater control. Other than that, the orifice outlet attached to the storage facility was dominant in determining the flow than the storage depth

Modelling the Outlet of Multi-Chamber Stormwater Detention System

Outlet size influences the detention volume that is crucial in a stormwater system. This paper describes an application of improving the outlet size of such a system. A field test is built in a terraced house that consists of a 4.40m x 4.70m x 0.45m multi-chamber stormwater detention tank connected to 0.1m diameter inlet and 0.05m diameter outlet. During field monitoring, an overtopping event is observed that puts a quest to re-look into its design. The field test has enabled the data collection of ten storm events with peak rainfall ranging from 20-48mm. A stormwater detention model is developed using the US Environmental Protection Agency’s Storm Water Management Model (SWMM). Calibration of the model with the observed storm events has returned with good matches with R Square values more than 0.9.With the calibrated model, investigations into the outlet sizes of 0.050m, 0.055m and 0.063m are carried out. The existing field test setup with the outlet size of 0.050m has water levels in the detention tank higher than the expected design values; and therefore, overtopping is observed for rainfall depth over 40mm. By simulating a scenario of enlarging the outlet size to 0.055m, the system is improved to accommodate rainfall depth up to 45mm, but overtopping is expected for rainfall depth over 45mm. By simulating another scenario of enlarging the outlet size further to 0.063m, the possibility of overtopping is eliminated but at a cost of achieving only in average 10% of attenuation between peak inflow and peak outflow. It is the least attenuation rate compared to average 30% for 0.050m and 20% for 0.055m. In short, the modelling efforts are demonstrated as a practical solution to the improvement of the intended stormwater detention system

Environmental Performance of the Stormpav Permeable Pavement Using the Stormwater Management Model (SWMM)

Urban stormwater runoff is contaminated with a variety of pollutants, including total suspended solids (TSS) and total phosphorus (TP), as a result of non-source pollution from transportation, residences, and businesses, as well as sediment from human activities and construction sites. These pollutants are expected to degrade the water quality in local rivers and streams, impairing the quality of marine life and contaminating drinking water supplies. This study evaluates the environmental performance of a permeable pavement system in an urban catchment using the stormwater management model (SWMM). Two pavement systems with different hydraulic designs were compared to reduce runoff, increment of groundwater storage and the environmental parameters assessments on total suspended solids (TSS) and Total Phosphorus (TP). The first system comprises a StormPav, which is the UNIMAS innovated green pavement with subsurface hollow cylindrical micro-detention pond storage of about 70% void content. The second system consists of porous concrete (PC) pavement assembled in a layered of coarse and fine particles to ensure water can infiltrate through, with about 40% void content. The environmental impact assessment was applied at Padungan Commercial Centre in the Kuching City of Malaysia. The case study simulated  low impact development (LID) sub-catchment in SWMM to obtain the runoff, infiltration and environmental quality performance. In the assessment, it was found that, for both pavement systems, higher storms at shorter duration resulted in higher reduction efficiency. The StormPav is more effective in reducing runoff while presenting a lower value for environmental assessments in removing TSS and TP compared to PC

Environmental Performance of the Stormpav Permeable Pavement Using the Stormwater Management Model (SWMM)

Urban stormwater runoff is contaminated with a variety of pollutants, including total suspended solids (TSS) and total phosphorus (TP), as a result of non-source pollution from transportation, residences, and businesses, as well as sediment from human activities and construction sites. These pollutants are expected to degrade the water quality in local rivers and streams, impairing the quality of marine life and contaminating drinking water supplies. This study evaluates the environmental performance of a permeable pavement system in an urban catchment using the stormwater management model (SWMM). Two pavement systems with different hydraulic designs were compared to reduce runoff, increment of groundwater storage and the environmental parameters assessments on total suspended solids (TSS) and Total Phosphorus (TP). The first system comprises a StormPav, which is the UNIMAS innovated green pavement with subsurface hollow cylindrical micro-detention pond storage of about 70% void content. The second system consists of porous concrete (PC) pavement assembled in a layered of coarse and fine particles to ensure water can infiltrate through, with about 40% void content. The environmental impact assessment was applied at Padungan Commercial Centre in the Kuching City of Malaysia. The case study simulated  low impact development (LID) sub-catchment in SWMM to obtain the runoff, infiltration and environmental quality performance. In the assessment, it was found that, for both pavement systems, higher storms at shorter duration resulted in higher reduction efficiency. The StormPav is more effective in reducing runoff while presenting a lower value for environmental assessments in removing TSS and TP compared to PC

Hydrological impact assessment on permeable road pavement with subsurface precast micro-detention pond

The purpose of this paper is to study stormwater management potential of new permeable pavement with subsurface micro-detention storage (PPDS) at low-speed residential suburban area. The main features incorporated permeable pavement of a hollow micro cylinder precast structure with solid hexagon precast concrete as top and bottom covers. The purpose of hollow micro detention design is for rainwater holding and void between the sets is for self-drying through the side and bottom seepage during rain. The hydrological parameters were obtained from laboratory rainfall simulator experiment. The performance was evaluated via simulation with Storm Water Management Model (SWMM). The outcomes from the physical model matched well with SWMM. A case study was then developed to assess the hydrological impact of PPDS with the existing condition and other types of permeable pavements. Significant variance was observed, where PPDS displayed its best hydrological performances for stormwater management with the presence of subsurface detention storage

Engineering Mathematics I: A Case Study of First Year Students at Faculty of Engineering, UNIMAS

The subject of mathematics is important as a prerequisite and requirement as most topics in engineering courses widely employ these fundamentals. The paper will describe an analysis based on Engineering Mathematics I course results for first year student of Semester I 2009/2010 academic year at the Faculty of Engineering, University of Malaysia Sarawak (UNIMAS). The aim is to identify the topics within Engineering Mathematics I, which may cause some difficulties for new students to understand. The performance that directly related to the students’ weaknesses is obtained from the continuous assessments of the course, end of semester report analysis based on course outcomes and item analysis. The results will be used as the basis for improving the teaching and learning process for this course

Accommodating stormwater storage structure in the veranda of shop building

This paper describes the investigation to place water storage structure under the veranda of a shop building. A veranda is a commercial building feature in Southeast Asia with a narrow walkway about 3 m wide. Given the small space’s limited capability to hold rainwater from the building roof, a draining tank is, therefore, a more viable choice. Rainwaters flow in and out the tank simultaneously with an outlet control that enables water storage within. A modular-based stormwater storage system that could be assembled under the veranda was selected. Storm Water Management Model version 5.0 was used to model the system. The modular-based system's availability of field test data allowed calibration and verification exercises using the mentioned software and yielded R Square values between 0.97-0.99. As such, the parameters of the system as a storage unit were applied in the modelling of the same system in the veranda. Two cases were presented. The water storage structure was modelled in a single shop lot and a partial commercial area with six units of shop lots and surrounding streets. Modelling the single shop lot with 60% of its roof directing waters to the water storage structure was predicted to reduce 25-30% of its peak values comparing the post-development hydrographs with and without the intervention. The partial commercial area modelling yielded only 0.4-10% prediction in its reduction, suggesting additional intervention was required

ENVIRONMENTAL ASSESSMENT OF STORMPAV GREEN PAVEMENT FOR STORMWATER MANAGEMENT

This study evaluates the stormwater management potential of a green pavement technology for permeable road pavement with subsurface micro-detention storage (StormPav) from a water quality perspective. The system provides integration of permeable pavement with hollow spaces to attenuate peak discharge with design installation using precast products. The environmental assessment was gathered from field experiments to assess the water quality, mosquito breeding capability and infiltration rate in the StormPav. The water quality parameters were determined to assess environmental benefits, which are one of the components of sustainable development. The parameters consist of total suspended solids, pH and alkalinity and they showed identical results to other permeable pavement types. Larvae development was found as early as eight days in stagnant water in the cylindrical hollow section of StormPav. However, the StormPav showed a high permeability rate within 122.45 mm/hr to 168.12 mm/hr at subgrade soil of HSG A soils group with no stagnant water retained in the void section in less than two hours, which nullified the required retention time for larvae development. Hence, StormPav displayed a significant benefit in terms of environmental concern for a sustainable design invention in stormwater management with the presence of subsurface detention storage

Transforming Physical Hands-on Laboratory Practice to Remote Laboratory Experimentation : A COVID-19 Experience

KNS 2601 is a laboratory course for Hydraulics and Geotechnical taught to Second-year students. The course exposes students to the technical background of hydraulics and geotechnical standard tests. Students are expected to comprehend and apply the principles of analysis and the scope of works in the hydraulics and geotechnical field. It is aimed to enhance students understanding from hands-on experience through standardized procedure and equipment provided in the laboratory. The experiments conducted are open-ended laboratory experimentations, where students need to come out with their own procedure and hypothesis. The course covers the psychomotor domain of P4 (Mechanism) and Critical Thinking (CT) skills. However, due to the COVID-19 pandemic, the instructors needed to outline a practical solution that could satisfy the outlined learning outcomes and expected taxonomies as quickly as possible. The pandemic hit us during the mid-semester break, when most students have completed half of the laboratory experiments (total of eight laboratory sessions) – leaving the course half-finished. Hence, a digitalbased learning experience with an introduction to virtual laboratory practice was introduced. Demonstration videos were prepared for students to access and ‘experience’ the experiments whilst not being physically present in the laboratory