Construction Technologies and Architecture Vol. 16

Abstract: Indonesia faces heightened vulnerability to flooding, making it one of the most frequent natural disasters in the country. In 2020, flood incidents peaked at 1,531, with 1,198 recorded in 2021. Makassar City, in South Sulawesi, experienced severe flooding, particularly at the junction of the Mangalarang and Kajenjeng Rivers, where hydrodynamic interactions exacerbate flood conditions. Nipa-nipa regulation ponds were established to mitigate these issues by focusing on hydraulic behavior during floods. This study examines hydraulic streamline flow at this junction using hydrographic surveys, topographic data, and 2D hydrodynamic simulations via Hec-Ras 6.4. The hydrological analysis incorporates frequency analysis and the Gama synthetic unit hydrograph method, while hydrodynamic modeling adheres to NRCS guidelines, employing a 2D transient flow model for accuracy. Results reveal that the Mangalarang River is the sole source of inflow into the nipa-nipa reservoir spillway, impeding the Kajenjeng River's discharge.

Abstract: Reclamation is a development process that extends towards the sea with the addition of new land on the coast. The reclamation of the Center of Point Indonesia Makassar made the current flow pattern change from the direction of the sea. The aim of this research is to analyze tidal current patterns around the Center Point Of Indonesia Makassar beach and analyze the influence of Center Point Of Indonesia (CPI) beach reclamation on tidal current patterns on Losari beach. This research method is by collecting secondary data and primary data. The data required includes tidal data, wind data, current data and thopography and bhatimetry data. The collected data is complete, so the next step is to process the data using Mike 21 with Flow Model FM 2D modeling to get results that show changes in current patterns due to tides and wind. As for the results obtained, the current speed at high tide conditions on 2/8/2023 at 05.00 Am showed that the current speed was 0.13 m/s in front of the Indonesian Center of Points reclamation and the lowest current speed was in the area within the reclamation or precisely in the area in front of Losari Beach. with a speed of 0.022 m/s. in spring tide conditions or conditions where the moon is not aligned with the sun on 8/8/2023 the current speed in front of the Losari beach area is 0.032 m/s.

Abstract: Flooding in the Latuppa Watershed almost always occurs when the rainy season arrives which is influenced by various factors. Starting from quite high rainfall, soil type, land use, to topographic conditions, slope, and river flow density. This study aims to determine the distribution zone of potential flood hazards at the research location using a Geographic Information System (GIS). The method used is Multi-Criteria Evaluation (MCE) analysis which combines Flood Hazard Index (FHI) related to GIS environment. This study also uses Analytical Hierarchy Process (AHP) in determining the weight of each flood parameter. Research data in the form of secondary data was taken through Indonesia Geospatial Data Portal of the Geospatial Information Agency and Watershed Management Information System data of the Ministry of Environment and Forestry. The results of the study were in the form of a flood hazard map showing the distribution of potential flood locations. The location of high flood hazard occurs in almost all downstream parts of the Latuppa atershed which covers most of Wara Timur, Wara Selatan, Wara, Sendana and Mungkajang Districts with an area of 1847.31 ha (27.06%) with Ammasangan, Dangerakko and Lagaligo Districts dominating the most. Then, moderate vulnerability is evenly distributed in all urban villages with an area of 3199.54 ha (46.87%) and the low-level vulnerability class category has a distribution of 1779.23 ha (26.07%) which is dominated by forest land use. The results of this study are expected to be a reference in future research, and can be a literature study to take policies related to flood management in the Latuppa Watershed.

Abstract: Morphological changes in shoreline areas are typically induced by the construction of structures in their vicinity. At Sanur Beach, the impact of the harbor's development is evident in shoreline changes, primarily in the form of accretion in the northern part of the breakwater. This study examines shoreline changes from 2018 to 2023, utilizing a remote sensing approach with Sentinel-2 Satellite Imagery. Sentinel-2 satellite image data in the Sanur Beach area undergo a process to generate a shoreline change map. The analysis is carried out using the Digital Shoreline Analysis System (DSAS) plugin in ArcGIS to determine the rate of change in meters/year and the area in m². The simulation results indicate shoreline changes as follows: in the period of 2018-2019, there was a tendency towards erosion with an average rate of-4.28 m, continuing into 2019-2020 with a rate of-4.62 m. The most significant change occurred in 2020-2021, characterized by erosion, with the highest rate being-7.28 m compared to the previous year. However, in 2021-2022, the change pattern shifted towards accretion at a rate of 11.88 m, and in 2022-2023, there was a tendency towards accretion at a rate of 4.01 m. These changes are influenced by the hydrodynamic factors at Sanur Beach, where the dominant wind directions are towards the east and southwest, resulting in the prevailing seaward flow from north to south. After the construction of Sanur Harbor, the shoreline changes tended to exhibit accretion, in contrast to the pre-construction period dominated by erosion.

Abstract: The selection of a procurement system through Design-Build is one of the alternatives for reducing the project implementation schedule, but time delays still occur. This study aims to determine the priority of risk sources and risk control strategies using the house of risk method through a questionnaire given to experts as respondents. Forty risk events and 17 risk agents will be assigned to contractors experienced in design-build construction on building projects. Based on the analysis results, the highest risk priority was that the contract between the project owner and the design-build contractor was unclear or contained ambiguities. The highest risk management strategy priority is on Strong and continuous communication and collaboration among all parties involved, including project owners, designers, contractors, and subcontractors, while the lowest risk control strategy is negotiation and agreement when facing unclear or inaccurate information, involving the owner in an open and constructive negotiation process. The findings will provide deeper insight into the effectiveness of risk control strategies for contractors and owners. not only that, the results of this study can be used as material in making improvements to the Design-Build method in minimising the potential for construction project delays.

Abstract: Buton Island is one of the largest Islamic Sultanate territories in Indonesia. One of the remains of the Buton Sultanate is the Grand Mosque of the Buton Sultanate (TGMOTSOB). TGMOTSOB was founded in 1537 and 1929 and renovated by the 37th Sultan of Buton. Over time TGMOTSOB has experienced changes in the appearance of the building. Changes in form in architecture fall within the scope of synchronic and diachronic. Changes in architecture and morphology correlate synchronically and diachronically. This correlation is important to explore to explain changes in ideas and meanings in the history of the building. This systematic review aims to: 1) gain a deeper understanding of the architectural morphology at TGMOTSOB; and 2) This systematic review can identify the instruments used to measure TGMOTSOB architectural morphology. This research concludes that TGMOTSOB can be studied by architectural morphology with building materials, building color, and changes in building shape based on factors of need and demand, technology, and political needs. Keywords: Changes in building shape, building materials, building colour.

Abstract: South Sulawesi is one of Indonesia's provinces with great potential in the construction sector. However, South Sulawesi faces various challenges in the construction sector, including construction disputes. This study aims to analyze the factors that cause construction disputes between small, medium, and large construction companies in South Sulawesi. Data were collected using questionnaires to project stakeholders and previous research. The method used was Structural Equation Modeling with a Partial Least Squares system. Seven factors cause disputes in construction projects, namely the problem of completeness of working drawings, changes in plan drawings, administration of approval of drawing changes, legal factors, weather change time factors, non-achievement of planned building quality, and increases in material prices and wages. The influential factors are time 67.8%, administration 53.8%, cost 48.0%, quality 45.2%, human resources 44.4%, technical 39.8%, and legal 39.2%. Thus, the time factor is the most influential in construction disputes in South Sulawesi.