A Novel Experimental Study on the Effects of Soil and Faults’ Properties on Tunnels Induced by Normal and Reverse Faults

Due to the world population increasing considerably, there is a need for efficient public transportation, such as the subway. However, it has become a major concern to geotechnical engineers that the development and construction of subways are held underground where faults exist, as it will be a major risk to any structure if the fault is still active. Several seismic events, such as the earthquakes in Taiwan in 1999, China in 2008, and Malaysia (Sabah) in 2015, caused by fault ruptures, signify the importance of this study. In this paper, a physical model of 1000 mm in height, 3000 mm in length, and 1000 mm in width, which is the largest single gravity (1g) model for simulation faults (normal and reverse) ever built, was fabricated to evaluate the influence of various soil properties, various fault angles, and tunnel depths on tunnels affected by normal and reverse faults. The effects of various soil properties, such as water content, particle size, cohesion, and friction angle, had revealed major changes (approximately by 34%, 39%, 64%, and 39%, respectively) in tunnel displacements. Results also showed that increasing of fault angle could increase the tunnel displacement as much as two times. In addition, when a tunnel is located close to the ground surface, 22% less displacement was found to have occurred to the tunnel. With the results obtained from the physical model, simulation had been made using plane strain and axial symmetry (PLAXIS) software. The comparison made between rock and soft soil showed that soft soil imposed two times more displacements than rock, and an existence of foundation in soft soil and rock can decrease the tunnel displacements by 6% and 4%, respectively. This paper asserts that besides the structural design of a tunnel, the geotechnical design also has a major impact on the safety and robustness of the tunnel, in which aspects such as soil properties, tunnel depth, and fault angle have a strong influence on tunnel damages which were not considered in previous research, despite their importance.

The Eksperimentation Study of Wave Transmission Trough Type Of Hollow Cube Breakwater

Erosion that occurs in break water by wave sand currents is a serious problem along coastal and inland shore [1]. This study aimed to assess the effect of the model height (Hm) and the pole density on the model on the reduction of the wave height and on the relationship between the non-dimensional parameter. The research was experimental with 2D physical model simulation which was conducted in the laboratory of Marine Engineering Faculty, Hasanuddin University. Several of configurations of Hollow-type breakwater models were made with different densities and model heights. The model scale use was 1:10 for the three model variations ((M1KB, M2KB, and M3KB) with the variations of the periods and of the wave height, at 0,25 m water depth. The research results indicated that the parameters which showed significant effects were the model height and the model density. These parameters showed the t

Novel dual-redundancy electro-hydrostatic actuator research and controller design

The paper proposes a novel dual-redundancy motor pump for the electro-hydrostatic actuator. Rather than the traditional single motor pump electro-hydrostatic actuator system, the system proposed in this paper can operate in three working modes and automatically adjust its operating condition in accordance with task requirements. The novel dual-redundancy electro-hydrostatic actuator system prototype was developed, and a high-performance control method was proposed and applied to the system, combining proportional–integral–derivative and sliding mode control to study the control strategy and implementation method of double closed loop. In addition, a physical model simulation was conducted on the basis of Amesim for this electro-hydrostatic actuator under several working conditions. Results showed that the dual-redundancy electro-hydrostatic actuator can decrease power loss and demonstrate excellent performance and reliability.

Pengaruh Screen Layer Breakwater Terhadap Tinggi Run UP Gelombang pada Revetmen

Erosion that occurs in revetment by waves and currents is a serious problem along coastal and inland shore 1. The aims of the study are to obtain influential parameter, to reduce the height of run up in the revetmet and get a non dimensional parameter of the relationship between the wave height and the wave run up on the revetment. The research is an experimental research with 2D physical model simulation, conducted in the laboratory of with some configurations of screen layer breakwater configuration models made from textile fabric with density and number of layer of different models. The model scale was 1:10 with three variations for models ((M1SL, M2SL, and M3SL) with variations of wave length and wave height, on some level of depth: 20, 15, and 10 cm. The results of the research indicated that the parameters found in this study are wave period (T), wave height (H), water depth (d), screen density (), the number of layers (N) and the distanceof the screen (Xm). The run up tend to decrease as the screen density value has smaller number of layers (N) and the distanceof the screen (Xm). In general, the study indicated that the stake of the screen layer can reduce the height of the run up in the revetment structure . The slope tan300 was 33% and produces non regression equation that shows the relationship between the dimensionless parameterwith run up (Ru/H), obtained Ru/H =, where= (); a and b respectively 2.9935 and 0.1293.