Journal of the Civil Engineering Forum

Enhancing Urban Resilience through Strategic Parking Pricing in Jakarta’s Bus Rapid Transit Corridors

Tue, 01 Oct 2024 20:25:33 +0700

Although Jakarta has invested in various mass transport systems, these efforts have not successfully reduced private vehicle use. Due to this, this study aims to analyze the impact of implementing TransJakarta bus rapid transit corridor-based high parking tariffs on travel mode choice, including road- and rail-based public transport, ride-hailing, taxi, car, and motorcycle. Involving 478 private vehicle users and implementing a nested logit model, some variables, including respondents’ income, travel time, egress time, parking costs, parking distance, travel cost, and parking surcharge, are considered to understand to what extent these variables influence the use of proposed travel mode in the future. The nested logit model shows that not all variables significantly influence travel mode use, specifically related to rail-based public transport choice among motorcyclists. Meanwhile,
parking distance insignificantly influences the choice of all travel modes except cars among car users. The results also indicate that increasing parking tariffs insignificantly influences the likelihood of both motorcyclists and car users shifting to public transport. Motorcyclists and car users tend to continue using motorcycles but change parking locations with higher tariffs. Additionally, some shifts towards ride-hailing services and TransJakarta Bus Rapid Transit are found, meaning that there is potential for these alternatives to play a significant role in reducing private vehicle use. Based on the model results, additional push-based policies, such as the odd-even license plate rule, are necessary to effectively support the transition from private vehicle use to public transport. Implementing these policies is expected to significantly contribute to reducing traffic congestion and promoting a sustainable and resilient urban environment.

Field Study of Deposit and Erosion Patterns around Pandanus Clusters Driven by Hydrodynamic Waves: A Preliminary Field Investigation

Nizam, Benazir, Muhammad S. I. Ibrahim, Oki Setyandito, Purnomo — Mon, 07 Oct 2024 12:53:30 +0700

Coastal zones are inherently dynamic, often resulting in long-term cumulative impacts such as erosion, which can potentially escalate into disasters. Discussions regarding nature-based solutions, particularly the utilization of coastal forests, have gained prominence due to their environ[1]mental benefits. This paper investigates the role of vegetated coasts in mitigating the effects of wave attacks on land, focusing specifically on Coastal Pandanus species. We conducted a systematic monitoring effort to quantify land changes directly around these species in the field. The southern coast of Java, characterized by significant coastal processes, served as the investigation site. We monitored the changes in the foredunes of eight Pandanus clusters identified along a 1 km stretch of the Pandansari and Samas coasts in the Special Region of Yogyakarta, Indonesia. Our systematic monitoring, conducted biweekly from September to December 2023, involved precise measurements of land elevation, sediment deposition, and erosion around the Pandanus clusters. We utilized manual leveling surveys and installed erosion pins to enhance the precision of our topographic assessments. These monitoring techniques allowed us to thoroughly examine the relationship between Pandanus cluster characteristics and coastal processes. Our findings illuminate the pivotal role of Pandanus clusters in shaping coastal profiles, which depend on cluster area and growth characteristics. Additionally, we underscore key points regarding their success rates, limitations, and future strengthening efforts through the implementation of this nature-based solution. This research contributes to a deeper understanding of the complex interactions between coastal dynamics and vegetative elements, paving the way for informed coastal management strategies in the future.

Debris Flow Debris Flow Detection by Combinations of LVP Sensors and Wires: Examples in Sakura-jima Island in Japan

Takahiro Itoh, Satoshi Tagata, Takahisa Mizuyama — Mon, 02 Dec 2024 14:00:50 +0700

Various kinds of sensors for debris flows detection have been proposed such as wire sensor, acceleration sensor, and so on. In Europe, a geophone that is based on a vibration meter is usually used though the applicability is not confirmed for debris flow detection in Japan. A wire sensor is still currently used for debris flow detection in Japan, because of its easy maintenance and measurement principle of disconnected wires. However, there is a drawback in that debris flow cannot be detected until manual maintenance is performed after the wires are disconnected. Sakura-jima is in southwest of Japan. Debris flows occur by rainfall and ash fall after eruption. Many debris flows occur and transport sediment by debris flow events. The number of debris flow occurrences is defined by the number of disconnected wires from a wire sensor, and three wires are set vertically at the height of 60 cm, 120 cm, 180 cm from the bed, respectively, to know magnitude of debris flow height. A LVP sensor has been developed and installed there for continuous detection of debris flows and modified based on technical information obtained by maintenance after debris flow events. The sensor consists of load cell (L), acceleration meter due to vibration (V) and pressure meter (P). The sensor is mainly for debris flow detection, though weight of debris flows on the bed is attempted to be measured using a small box with loadcell. Present studies introduce some examples of debris flow detections using the LVP and emphasize usage of the LVP sensor in combination with wires.

GIS-based calculation method to predict mining subsidence in flat and inclined mining: A comparative case study

Ibrahim Djamaluddin, Poppy Indrayani, Yue Cai, Yujing Jiang — Mon, 02 Dec 2024 14:11:56 +0700

Prediction of ground movements in the case of continuous subsidence is critically important for the planning of underground mining. Many calculation models are used to predict mining subsidence. A comprehensive method to render current calculation models superfluous can only come from a theoretical model, but the challenge remains in defining the parameters, given the great variety of rock structures found. Hence, innovation through a conceptual and technological study of the subsidence mechanism is needed to ensure that this problem can be solved satisfactorily. In this study, a new method is proposed to predict ground surface subsidence by combining a stochastic medium concept with Geographic Information System (GIS) technology. All subsidence computations are implemented within GIS, where spatial components are used to conduct the subsidence prediction analysis. This paper includes simulations of basic subsidence phenomena and a comparative study of the GIS-based calculation method’s suitability against the empirical method from the Subsidence Engineer Handbook (SEH), semi-empirical influence function models, and numerical modeling. First, the influence of basic extraction area categories on the character of mining subsidence at the surface for flat seam layers is verified. Second, subsidence and horizontal displacement profiles are compared for both gently and steeply inclined mining. Finally, the verification of calculated horizontal strain values for an actual case of inclined irregular mining is also conducted. The comparative results of subsidence predictions for flat and gently sloping mining demonstrate the suitability of the GIS-based calculation method for use in underground mining strategy.

Unveiling Differences in Seismic Response: Comparative Study of Equivalent Linear and Nonlinear Analyses in the Central Coastal Region of Bengkulu, Indonesia

Tue, 10 Dec 2024 16:05:50 +0700

Seismic response analysis is a key aspect in earthquake geotechnical engineering, as it provides important insights into the behavior of soils when exposedtoseismic forces. This research compares equivalent linear and non-linear models in the central coastal region of Bengkulu, which is known for its complex geology and high seismicity. By evaluating the accuracy and reliability of each model in predicting ground motion amplification, this research aims to provide useful recommendations for seismic design. The research method uses one-dimensional equivalent linear and nonlinear propagation modeling, namely Pressure Dependent Hyperbolic (PDH). The analysis resulted in the parameters of Peak Ground Acceleration (PGA), time history acceleration, spectral response acceleration, and amplification factor. The equivalent linear method consistently produced higher values for peak ground acceleration (PGA), spectral response acceleration, time history acceleration, and amplification factor compared to the nonlinear method. The analysis results show that the equivalent linear PGA values are in the range of 0.32g to 0.63g, while the nonlinear values range from 0.20g to 0.52g. The resulting spectral responses are averaged over the design spectrum within 0.2 s to 0.9 s, which can affect low- to high-ceilinged buildings. The equivalent linear amplification factor has a range of 1.59 to 1.91, while the nonlinear has a range of 0.80 to 1.59. Both methods have their advantages, with the nonlinear approach offering greater accuracy for large seismic events, while the equivalent linear model remains useful for preliminary analysis. Hopefully, these findings will improve the understanding of ground response in coastal areas and provide valuable data for improving infrastructure resilience in earthquake-prone areas around the world.