A series of centrifuge model tests has been conducted to examine the behavior of laterally loaded pile groups in normally consolidated and overconsolidated kaolin clay. The pile groups have a symmetrical plan layout consisting of 2, 2ϫ2, 2ϫ3, 3ϫ3, and 4ϫ4 piles with a center-to-center spacing of three or five times the pile width. The piles are connected by a solid aluminum pile cap placed just above the ground level. The pile load test results are expressed in terms of lateral load-pile head displacement response of the pile group, load experienced by individual piles in the group, and bending moment profile along individual pile shafts. It is established that the pile group efficiency reduces significantly with increasing number of piles in a group. The tests also reveal the shadowing effect phenomenon in which the front piles experience larger load and bending moment than that of the trailing piles. The shadowing effect is most significant for the lead row piles and considerably less significant for subsequent rows of trailing piles. The approach adopted by many researchers of taking the average performance of piles in the same row is found to be inappropriate for the middle rows, of piles for large pile groups as the outer piles in the row carry significantly more load and experience considerably higher bending moment than those of the inner piles.

Indonesia is a country with large and dynamic economic activities reflected by an average economic growth reaching 6% per annum. Sunda Street Bridge (SSB) is one of the mega projects offered by the Indonesia government that would spend about US$ 25 billion. In line with the SSB main function as an efficient mean for transporting people and goods between two major islands in Indonesia, potential additional functions have been explored including installation of liquid and gas pipes, fiber optics, industrial area development and renewable energy utilization. This research establishes the approach to forecast demand in the case of conceptual design. The SSB is associated with innovations to determine the functions using value engineering methods. The approach involves forecasting demand with a System Dynamics simulation model that could provide a reliable estimate and generate scenarios to compare the financial feasibility of the project before and after the process involving innovation of project functions. Analysis involving demand forecasting with the System Dynamics Approach has confirmed that the Sunda Strait Bridge development with additional functions would increase the revenues of the overall project up to US$61.59 Million, in order to obtain an increased Internal Rate of Return (IRR) of the overall project up to 7.56% with a positive Net Present Value (NPV).

Estimation of land subsidence induced by groundwater extraction has been observed by some researchers using field instrumentation as well as a spatial mapping technique. Among six Asian cities previously studied (Bangkok, Jakarta, Manila, Osaka, Seoul, Taipei, and Tokyo), the rate of land subsidence in Jakarta is the highest in the period from 1900-2010. In order to improve the applicable monitoring system and obtain comprehensive results for subsidence measurement, tools for raising the government's and society's awareness of subsidence are needed. This paper aimed to determine a benchmark and perform an analysis of sustainable counter measures for land subsidence induced by groundwater extraction in the urban areas of Jakarta city, using a continuous monitoring system and integrated data management system. Land subsidence was measured using field monitoring techniques, such as an extensometer, a leveling survey (global positioning system,GPS; geodetic measurements), and observation wells; this was conducted in some locations in north Jakarta from 1990-2016. The results from the visual observation identified an average land subsidence rate of 1.65 cm/year, while the GPS geodetic measurements ranged from 0-12 cm/year. Monitoring from seven extensometer sensors installed in different borehole elevations revealed subsidence of 0.66 cm on average. Meanwhile, the groundwater surface level ranged from 0.6 m to 44 m from the surface, with the deepest being in the area of Bintaro, South Tangerang. Data analysis was conducted using a computer simulation to investigate the inter-connection between land subsidence and groundwater extraction. Consequently, land subsidence was found to have a strong association with groundwater extraction. Integrated data management systems, including data sharing, are needed to improve the appropriate monitoring system of land subsidence in Jakarta.

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This study discusses the evaluation of Hara's model to estimate seismic moment magnitude (M W ) by using teleseismic waveform data, and then presents the development of an extended Hara model. Both models use the maximum amplitude of displacement and epicenter distance, as well as the duration of high-frequency energy radiation, of the vertical component of earthquake P-wave records. Nineteen moderate-magnitude (5.0  M W  7.0), shallow (depths  70 km), Sumatra subduction megathrust earthquake data sets recorded by the KAPI seismograph station (Kappang, South Sulawesi) in 2010 and 2011 were used in this study. The analysis is performed to obtain the maximum amplitude of displacement, epicenter distance, and the duration of high-frequency energy radiation on the first arriving P-wave. The main results show that Hara's model (2007) overestimates M W to be less than 7.0 compared with that obtained from the Global Centroid Moment Tensor (CMT) catalog. The extended Hara model was developed with the use of the same basic equation, and the resulting coefficients are α = 0.538792, β = 0.783840, γ = 0.242616, and δ = 4.929095. The mean and standard deviation of the difference between the extended Hara model and the Global CMT catalog are 0.01 and 0.14, respectively.