Abstract Rainfall-induced slope failures frequently occurs in many urban areas around the world especially due to the impact of the global warming. Some slope failures result in casualties that have negative impacts on urban sustainability. The slope failures are normally observed near slope surface within the unsaturated zone above the groundwater table. Hence, it is important to incorporate the unsaturated soil mechanics principles in analysing the slope stability during rainfall. This study focuses predominantly on the regional stability analyses of residual soils within the Jurong Formation and Bukit Timah Granite in Singapore. The objective of the study is to develop slope susceptibility map as part of preventive measures against extreme rainfall conditions. The slope susceptibility map was evaluated using 2-D numerical analyses of slopes with historical failure. The recently developed sustainable retaining structure system, GeoBarrier System (GBS) is investigated to understand its suitability as a preventive measure for critical slopes with high risk as identified from the slope susceptibility map. Using Transient Rainfall Infiltration (TRIGRS) and Grid-Based Regional Slope Stability Analysis (Scoops3D), the pore-water pressure distributions and factors of safety (FS) within each zone are determined. The results from slope susceptibility maps and 2-D numerical analyses are consistent. Moreover, the incorporation of GeoBarrier System on the critical slope is demonstrated to be an effective slope stabilization measure based on the numerical simulations of two-dimensional analyses. 

Slope susceptibility map for preventive measures against rainfall-induced slope failure

Floods are an issue that results in losses, and thus attempts to solve the problem of flooding are attempts to minimize losses. To mitigate the losses incurred as much as possible, there are several approaches to deal with the loss through incident management and its impacts. The objective of this study is to investigate the variations in water level within Air Lakitan Watershed to monitor the fluctuations of water level for preventing flooding issues in the future. This research was carried out by analyzing the hydrodynamics of flow in irrigation canals in Irrigation Area II with an area of 928 hectares using the HEC-RAS program with rainfall data and flow hydraulics data. The study was carried out in Air Lakitan Watershed in Sumber Harta District, Musi Rawas Regency, Sumatra, Indonesia. Each portion of the studied irrigation canal’s water level and velocity, as measured by a current meter, are shown on graphs, as are the study’s overall conclusions for each observation station along the channel. Simulated data was acquired using a river crossing that is not filled and a discharge of 0.024 m3/s. From this research, it can be concluded that the Log-Pearson Type III distribution is the frequency distribution that matches the hydrological analysis in the research area. This method can be applied in analyses of river levels in other areas with heavy rainfall. Therefore, the water level upstream and downstream is the same at 0.41 m with a discharge of 1 m3/s; the river cross-section downstream with an existing discharge of 0.024 m3/s produces water height as high as 0.08 m and with a flow rate of 0.783 m/s, the water level at the downstream cross-section is filled up to 0.75 m high, and the water level downstream of the irrigation channel is up to 0.40 m.

/pdf/application-of-the-hec-ras-program-in-the-simulation-of-the-270l5u2s.pdf

Application of the HEC-RAS Program in the Simulation of the Streamflow Hydrograph for Air Lakitan Watershed

Mold growth on building materials not only affects the appearance of the buildings but also leads to poor indoor air quality, posing risks to occupants' health. Mold prediction models are the major way to help avoid mold growth in built environments, whereas the accuracy of mold prediction models highly depends on the input data from mold experiments. Although many studies have investigated the growth of molds on various building materials, there is a lack of homogeneity and consensus in the methods and protocols used, which hampers comparison of the results obtained. This review first summarizes the existing accelerated laboratory testing methods for mold growth on building materials, including both standard and derived methods. After that discussions are made on how experimental settings affect the reliability, repeatability, reproducibility, and comparability (3R1C) of mold experiments as well as their potential impact on mold risk evaluation. Finally, a guide for enhancing the 3R1C of the accelerated laboratory testing methods is made, with recommendations for experimental setups and an emphasis on building a universal agreement of evaluation methods and rating systems. Additionally, the need for concise and universally accepted standard testing methods is highlighted. Further research directions are also identified to advance the field. 

Comparison of mold experiments on building materials: A methodological review

The Moroccan road network is susceptible to multiple landslides annually, particularly in the northern regions due to high rainfall and specific geology. These events result in significant economic and social negative consequences, highlighting the need for sustainable and cost-effective solutions for network maintenance. This study outlines the methodology employed in addressing the issues within the RR410 regional road (Rifain region of Morocco), which entailed a thorough examination of the malfunctions, specific surveys, laboratory testing, and problem modeling. By incorporating long-term test-derived shear strength parameters, the model indicated that the road platform was stable, and back analysis using TALREN 4 software allows for model calibration. At kilometric point 23, using earthwork-based solutions (e.g., purging and replacing the base layer, employing granular water-insensitive substitution material) was found to provide a sustainable alternative to the expensive reinforced concrete-based solutions commonly used. Furthermore, these solutions contributed to the use of environmentally friendly and locally sourced materials. Road alignment rectification to anchor the platform in suitable soil was also an effective solution, as demonstrated at kilometric point 48. Additionally, enhancing the drainage and sanitation infrastructure, such as installing draining trenches, spurs, and reinforcing existing water structures, is a crucial aspect of addressing most landslides in the region.

/pdf/design-of-cost-effective-and-sustainable-treatments-of-old-1h6sn6yr.pdf

Design of Cost-Effective and Sustainable Treatments of Old Landslides Adapted to the Moroccan Road Network: A Case Study of Regional Road R410 Crossing the Rifan Structural Domain

The thermal effect of pile foundation in frozen ground is crucial for the formation of its bearing capacity. To break through the problems of strong thermal disturbance and slow formation of bearing capacity in the existing pile foundations. In this paper, a new type of pile named Pre-bored Grouting Planted Nodular (PGPN) was first introduced to the permafrost area, which was a prefabricated composite pile. Its unique structure can reduce the amount of cementitious materials and improve the bearing capacity. To reveal the thermal performance of the PGPN pile to warm permafrost, and compare with that of bored concrete pile, the model experiment and numerical simulation of the pile were conducted in this paper. It was found that: 1) The refreezing time and thermal disturbance radius of the PGPN pile were 270 days and 1.8 m, respectively, which were one-third and half of those of cast-in-place pile. The cemented-soil around the PGPN pile could significantly reduce its hydration heat and reduce the thermal disturbance to frozen ground. 2) Because of the high cement concentration in cemented-soil, the early hydration reaction of the pile was strong, and the temporary high temperature provided a favorable environment for the strength maintenance of cemented-soil in frozen soil. On the contrary, the hydration reaction of bored concrete pile lasted a long time, which intensified the degree of thermal disturbance to permafrost; and 3) Affected by the cooling effect of the atmospheric environment and the self-recovery effect of the lower permafrost, the temperature field of the pile foundation refrozen from the upper and lower ends to the middle. The structure of the frozen soil was changed by hydration heat, making it difficult to return to its initial state. The research results can provide data support for the promotion and application of prefabricated pile foundation in permafrost regions. 

Thermal performance and applied evaluation of the pre-Bored grouting planted nodular pile in warm frozen soil

Nowadays, the application of Fungi as a bio-mediated soil improvement technique is developing. The hydraulic properties of Rhizopus Fungi-Mycelium Treated Soil are unknown, and the treated sample tends to have low durability. This article presents experimental results of hydraulic conductivity and shear strength of Fungi-mycelium-treated silica sand. The fungi used in the experiments are a combination of Rhizopus oligosporus and Rhizopus oryzae, which is popular for making Tempeh, a local soybean cuisine from Indonesia. The samples are made by mixing the sand with Tempeh inoculum with various treatments and Tempe inoculum and rice flour dosages for enhancing the durability of the treated soil. The results showed that the saturated permeability of the treated soil could decrease about 10 times compared with the untreated soil. In addition, the Soil-Water Characteristic Curve of treated soil also developed. The effect of fungi appears to fill the void of soil and hence increases the Air Entry Value and residual suction of soil. The curing method outside the mold (O-method) with 10% Tempeh inoculum, and 5% Tempeh inoculum with 5% rice flour is proven can extend the durability of the treated sample, the undrained compressive strength is about 40 kPa at day 14. Scanning electron microscope was performed on the samples that lasted 4 months. The mycelium and hyphae are still clearly seen covering all sand particles with different percentages of Tempeh inoculum and rice flour. When the mycelium covered all sand particles and filled the pores, the water flow would partially be blocked. It might be attributed to the strong hydrophobicity of fungi that could prevent water from penetrating the soil. 

Hydraulic Characteristics and Incubation Methods for Enhancing Durability of Fungi- Mycelium Treated Silica Sand using Rhizopus oligosporus and Rhizopus oryzae Combination

Many reclaimed areas in Indonesia have abandoned swampland or idle land which is attributed to various factors. One of the main factors is the unsuitability of the exiting flow system in this area since the condition of the canals and water structures in this area has not been rehabilitated for a long time. No study has been carried out to investigate the suitable model for simulating the appropriate criteria for assessment of erosion within the channel on Tidal lowland in Indonesia. This study focuses on the investigation of erosion occurring within the Rural Channel and Main Drainage Channel on Tidal lowland in Palembang, Indonesia which becomes the originality of this manuscript. The erosion was attributed to the accumulation of sediment transport within the channel of the reclaimed tidal delta region Telang I. The results of the research on the P8-13S scheme show that equilibrium on the accumulation of sediment transport in the channel was observed in the Rural Channel and Main Drainage Channel on average ranging from 3,301,859 m3 to 3,349,103 m3 while the average sedimentation ranged from 809,232–898,467 m3. This study is very important in minimizing the possible erosion near riverbank.

/pdf/sediment-transport-patterns-of-channels-on-tidal-lowland-298oyw4f.pdf

Sediment Transport Patterns of Channels on Tidal Lowland

Soil suction plays an important role in governing the stability of slopes. Environmental sustainability could be jeopardized by hazards, such as slope failures (forest destruction, landscape alteration, etc.). However, the quantification of the suction effect on slope stability is a challenging task as the soil suction is usually affected by the precipitation and evapotranspiration. Numerical simulation plays an important role in the estimation of contour in soil suction due to rainfall and evapotranspiration as long-term and widespread monitoring is rarely conducted. The result of numerical simulation is highly dependent on the accuracy of the input parameters. Hence, suction monitoring plays an important role in verifying the result of numerical simulation. However, as a conventional tensiometer is limited to 100 kPa soil suction, it is hard to verify the performance of numerical simulation where suction is higher than 100 kPa. The osmotic tensiometer developed by Nanyang Technological University (NTU) can overcome this problem. It is now possible to monitor changes in soil suction higher than 100 kPa (up to 2500 kPa) for an extended period in the field. In this study, a procedure was proposed to estimate suction changes in residual soil based on rainfall and evapotranspiration data. Numerical simulation was carried out based on the soil properties and geometry of a residual soil slope from Jurong Formation Singapore. Changes in soil suction due to rainfall and evaporation were simulated and compared with the readings from the NTU osmotic tensiometers installed at 0.15 m and 0.50 m from the slope surface in the field. It was observed that numerical simulation was able to capture the variations of suctions accurately at greater depths. However, at shallow depths, erratic suction changes due to difficulties in capturing transpiration.

/pdf/numerical-simulation-on-the-effect-of-infiltration-and-1g3e5j3c.pdf

Numerical Simulation on the Effect of Infiltration and Evapotranspiration on the Residual Slope

Mount Kaba is one of the active volcanoes located in the eastern part of Bengkulu Province. This research was conducted in Gunung Kaba Complex because the distribution location of the last eruption product is close to some monogenetic volcano and residential area. This is interesting to study considering because can be a potential threat of disaster. The results of this study are expected to support providing an overview of the potential threat of volcanic disasters in the Mount Kaba Complex. The research methods used include geomorphological, stratigraphic, petrographic, and geochemical analyses. The geomorphological unit of Mount Kaba consists of 6 units. The types of volcanic rocks in the research area are dominated by lava and pyroclastic rocks. Based on the petrographic analysis of 10 samples, the names of the rocks in the research area are basalt scoria, basalt, and andesite. Based on the geochemical analysis of 8 samples, it is known that silica content in the rocks ranging from 44.40925 - 63.2993 %. Based on the AFM diagram, all samples are included in the tholeiitic series. Based on the TAS (Total Alkali Silica) diagram, it is known that the igneous rocks of the study area consist of andesite, basalt, tephrite, and trachyandesite.

A Preliminary Volcanological Study of North Eastern Kaba Volcano, Bengkulu Province, Indonesia

Ignoring the role of soil suction and implementing unsaturated soil mechanics when assessing slope stability in Indonesia is a common practice. One of the main reasons is due to the precognition that incorporating soil suction means using higher shear strength, which leads to less conservative analysis, while it is difficult to practically obtain accurate input parameters for unsaturated soil analysis. However, a number of slope failures occur all over the world due to rainfall, which becomes evidence that ignoring the role of soil suction may not necessarily lead to a conservative result. On 9 January 2021, rainfall-induced slope failure occurred at Cimanggung after four hours of heavy rainfall and killed 32 people. Many of them were injured, and houses were destroyed. This event shows the significance of considering the interaction between infiltration and soil suction when conducting slope stability analysis. Difficulties in obtaining input parameters for unsaturated soil analysis experimentally hindered practitioners in applying unsaturated soil mechanics. While the parameters can be estimated, it is always of question whether the estimated parameters are sufficiently accurate for practical purposes. In this paper, conventional site investigations were carried out while unsaturated soil parameters were estimated to study the mechanism which triggers the landslide that occurred at Cimanggung. It will be shown that estimating unsaturated soil parameters can be practically accurate and manage to capture the failure mechanism such as critical rainfall duration and critical slip surface.

/pdf/practical-approach-for-assessing-wetting-induced-slope-3i3lm6uq.pdf

Practical Approach for Assessing Wetting-Induced Slope Failure

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

M. Wijaya

Author Tools

Chat about Author