Application of Smoothed Particle Hydrodynamics (SPH) for the Simulation of Flow-like Landslides on 3D Terrains

Flow-type landslide is one type of landslide that generally exhibits characteristics of high flow velocities, long jump distances, and poor predictability. Simulation of it facilitates propagation analysis and provides solutions for risk assessment and mitigation design. The smoothed particle hydrodynamics (SPH) method has been successfully applied to the simulation of two-dimensional (2D) and three-dimensional (3D) flow-like landslides. However, the influence of boundary resistance on the whole process of landslide failure is rarely discussed. In this study, a boundary algorithm considering the friction is proposed, and integrated into the boundary condition of the SPH method, and its accuracy is verified. Moreover, the Navier-Stokes equation combined with the non-Newtonian fluid rheology model was utilized to solve the dynamic behavior of the flow-like landslide. To verify its performance, the Shuicheng landslide event, which occurred in Guizhou, China, was taken as a case study. In the 2D simulation, a sensitivity analysis was conducted, and the results showed that the shearing strength parameters have more influence on the computation accuracy in comparison with the coefficient of viscosity. Afterwards, the dynamic characteristics of the landslide, such as the velocity and the impact area, were analyzed in the 3D simulation. The simulation results are in good agreement with the field investigations. The simulation results demonstrate that the SPH method performs well in reproducing the landslide process, and facilitates the analysis of landslide characteristics as well as the affected areas, which provides a scientific basis for conducting the risk assessment and disaster mitigation design.

Disain Mitigasi Risiko Penularan Covid-19 di Lingkungan Industri Padat Karya dengan Metode FMEA

Indonesia has confirmed its first case of Covid-19 transmission on March 2, 2020 and since then the transmission of the virus has become more widespread and has created new epicenters. The epicenter always involves a crowd, including in labor-intensive factory areas. This research method uses quantitative-descriptive. Companies that operating labor-intensive require the involvement of large numbers of people. In the production process, the distance between workers is not far apart, thus increasing the risk of virus transmission. The latest case in September 2020, 150 employees of a factory in the city of Purbalingga tested positive for the Covid-19 virus. It is strongly suspected that transmission occurs in the work area through asymptomatic labor. With the continued occurrence of Covid-19 transmission in industrial areas, this article aims to submit a proposal for the application of a risk mitigation design for the risk of Covid-19 transmission in labor-intensive industries using the FMEA method, which includes the layout of the work area, the flow of human movement in the factory area, and the application of health protocols in the hope of helping labor-intensive industries in suppressing and preventing the transmission of Covid-19

Analisis Karakteristik Wilayah Transmisi Covid-19 dengan Menggunakan Metode K-Means Clustering

Since the beginning of 2020, Indonesia has become one of the countries affected by the Covid-19 pandemic. Various efforts have been made by the government to prevent wider disease transmission. Large-scale social restrictions are one of the efforts that have been made by the Government. Bali Province is one of the areas where there are quite a lot of community activities, considering that Bali is a tourist destination that is in great demand by local and foreign tourists. This study aims to see the incidence of positive cases of Covid-19 based on the type of Covid-19 transmission that has occurred in all areas of Bali, so that the mitigation design can be adjusted based on the characteristics of the source of infection in various existing areas. The results show that based on the transmission source, it can be grouped into four clusters that have their respective characteristics. The proposed mitigation strategies include restrictions on local transmission and domestic travel for areas in clusters 1, 2, and 3. Meanwhile, restrictions on local transmission and overseas travel are in the 4th cluster. Sejak awal tahun 2020, Indonesia menjadi salah satu negara terkena pandemi Covid-19. Berbagai upaya telah dilakukan oleh pemerintah untuk mencegah transmisi penyakit yang lebih luas. Pembatasan sosial berskala besar menjadi salah satu upaya yang telah dilakukan oleh Pemerintah. Provinsi Bali merupakan salah satu wilayah yang cukup banyak terjadi aktivitas masyarakat, mengingat Bali merupakan kawasan destinasi wisata yang banyak diminati wisatawan lokal maupun mancanegara. Penelitian ini bertujuan untuk melihat kejadian kasus positif Covid-19 berdasarkan jenis transmisi Covid-19 yang terjadi di seluruh wilayah Bali, sehingga rancangan mitigasi dapat disesuaikan berdasarkan karakteristik sumber infeksi di berbagai wilayah yang ada. Hasil menunjukkan, bahwa berdasarkan sumber transmisi dapat dikelompokkan menjadi empat cluster yang memiliki karakteristik masing-masing. Usulan strategi mitigasi yang diberikan antara lain pembatasan transmisi lokal dan perjalanan dalam negeri untuk wilayah yang berada pada cluster 1, 2, dan 3. Sedangkan pembatasan transmisi lokal serta perjalanan luar negeri pada cluster ke-4.

Steep Creek Risk Assessment for Pipeline Design : A Case Study From British Columbia, Canada

ABSTRACT Pipelines in mountainous terrain often cross alluvial fans formed by steep creek processes of debris flows and debris floods and are thus exposed to their associated hazards. The design of new pipeline infrastructure and maintenance of existing pipelines necessitates steep creek risk assessments and appropriate mitigation design. We present methodology for assessing steep creek risk along pipeline routes that evaluates the probability of such processes causing a pipeline loss of containment or disruption in service. The methodology consists of estimating event frequency, scour potential, and the vulnerability of the pipeline to break if impacted by boulders. The approach can be adapted to other landslide geohazards so that different geohazard locations can be evaluated with a common metric. Steep creek process frequency is estimated based on field observations and review of documented events, historical air photo records, and terrain mapping based on LiDAR-generated topography. Scour potential is estimated based on channel morphology, presence of bedrock, and grain size distribution of channel bed material. Vulnerability is estimated based on flow width and velocity and can be modified for different pipe diameters and wall thicknesses. Mitigation options for buried pipelines include those intended to decrease the likelihood of the pipeline being exposed and to increase the resiliency of the pipeline to boulder or organic debris impacts, if exposed. The methodology presented is embedded in risk-informed decision making where pipeline owners and regulators can define probability thresholds to pipeline exposure or rupture, and pipeline designers can demonstrate that proposed mitigation measures achieve these threshold criteria.