Laporan ini meninjau keanekaragaman benthos dan nekton di hutan mangrove Pulau Sembilan, Sumatera Utara. Tujuannya adalah mengetahui jenis-jenis organisme yang hidup di mangrove serta hubungan antara vegetasi dan kondisi lingkungan terhadap kelimpahan spesies. Berbagai jenis moluska dan crustacea ditemukan yang bergantung pada mangrove sebagai habitat dan sumber makanan.
This document discusses a marketing solution involving Facebook message marketing. It will utilize Facebook mobile, desktop, and profile data as well as page, company and group information to target potential customers. The solution aims to engage customers through personalized messages.
This document describes Edition 3.1 of the Association of Geotechnical and Geoenvironmental Specialists' (AGS) format for the electronic transfer of geotechnical and geoenvironmental data. The AGS format was created to standardize the electronic transfer of subsurface investigation data between different software programs and users. This updated edition includes new groups, fields, pick lists, and determinand codes added based on user suggestions. It aims to incorporate commonly used additions to the format while maintaining compatibility with previous versions.
This document contains 17 references related to rock mechanics and rock engineering. The references span from 1931 to 1994 and include journal articles, conference proceedings, books, theses, and reports. The references cover topics such as rock mass classification systems, shear strength of rock joints, rockfall analysis, tunnel support, and case histories of rock engineering projects.
The document discusses blasting damage in rock excavations and methods to control it. It begins with a brief history of blasting and how the understanding of its effects on rock stability has lagged behind other areas of rock mechanics. Blasting can damage rock through dynamic stresses, gas pressure, and fracturing from the release of compressed rock. Precisely controlling blasting techniques from the initial cut through the full blast sequence is necessary to minimize damage extending several meters into the surrounding rock. Methods discussed include pre-splitting, smooth blasting, and the use of delays to allow broken rock to clear before subsequent holes detonate. Proper blasting design is crucial for ensuring the stability of underground excavations and rock slopes.
Shotcrete is a cement-based concrete that is pneumatically projected at high velocity onto underground excavation surfaces for rock support. There are two main types - dry mix, where materials are conveyed dry to the nozzle and water added, and wet mix, where materials are pre-mixed with water. Recent developments include adding steel fibers for reinforcement and microsilica for strength. Shotcrete provides effective support in mining when applied correctly using proper equipment and experienced operators. It is increasingly used for permanent openings and offers advantages over traditional rockbolt and mesh support.
Laporan ini meninjau keanekaragaman benthos dan nekton di hutan mangrove Pulau Sembilan, Sumatera Utara. Tujuannya adalah mengetahui jenis-jenis organisme yang hidup di mangrove serta hubungan antara vegetasi dan kondisi lingkungan terhadap kelimpahan spesies. Berbagai jenis moluska dan crustacea ditemukan yang bergantung pada mangrove sebagai habitat dan sumber makanan.
This document discusses a marketing solution involving Facebook message marketing. It will utilize Facebook mobile, desktop, and profile data as well as page, company and group information to target potential customers. The solution aims to engage customers through personalized messages.
This document describes Edition 3.1 of the Association of Geotechnical and Geoenvironmental Specialists' (AGS) format for the electronic transfer of geotechnical and geoenvironmental data. The AGS format was created to standardize the electronic transfer of subsurface investigation data between different software programs and users. This updated edition includes new groups, fields, pick lists, and determinand codes added based on user suggestions. It aims to incorporate commonly used additions to the format while maintaining compatibility with previous versions.
This document contains 17 references related to rock mechanics and rock engineering. The references span from 1931 to 1994 and include journal articles, conference proceedings, books, theses, and reports. The references cover topics such as rock mass classification systems, shear strength of rock joints, rockfall analysis, tunnel support, and case histories of rock engineering projects.
The document discusses blasting damage in rock excavations and methods to control it. It begins with a brief history of blasting and how the understanding of its effects on rock stability has lagged behind other areas of rock mechanics. Blasting can damage rock through dynamic stresses, gas pressure, and fracturing from the release of compressed rock. Precisely controlling blasting techniques from the initial cut through the full blast sequence is necessary to minimize damage extending several meters into the surrounding rock. Methods discussed include pre-splitting, smooth blasting, and the use of delays to allow broken rock to clear before subsequent holes detonate. Proper blasting design is crucial for ensuring the stability of underground excavations and rock slopes.
Shotcrete is a cement-based concrete that is pneumatically projected at high velocity onto underground excavation surfaces for rock support. There are two main types - dry mix, where materials are conveyed dry to the nozzle and water added, and wet mix, where materials are pre-mixed with water. Recent developments include adding steel fibers for reinforcement and microsilica for strength. Shotcrete provides effective support in mining when applied correctly using proper equipment and experienced operators. It is increasingly used for permanent openings and offers advantages over traditional rockbolt and mesh support.
This document discusses design considerations for large underground caverns excavated in weak rock at depths of 100-300m below the surface for hydroelectric projects. It addresses the stability of caverns and surrounding rock mass given in situ stress conditions, effects of nearby slopes, and determining appropriate pillar sizes between excavations. The key design factors are the strength of the rock mass, influence of structural features like joints and bedding planes, sequence of excavation and support, and stress changes induced by nearby slopes and excavations. Pillar size between caverns must consider stresses imposed and stability of the rock mass.
The document discusses rock mass properties and the Hoek-Brown failure criterion for estimating the strength of jointed rock masses. It presents the generalized Hoek-Brown criterion equation and describes how to determine the intact rock properties of uniaxial compressive strength (σci) and the Hoek-Brown constant (mi) from triaxial test data or estimates. It also discusses estimating the Geological Strength Index (GSI) of the rock mass.
This document discusses rockfall hazards and analysis. It begins with an introduction noting that rockfalls are a major hazard for mountainous transportation routes and have resulted in numerous deaths. It then discusses the mechanics of rockfalls, noting that slope geometry and surface materials are most important in determining rockfall trajectories. Various measures to reduce rockfall hazards are discussed, including identification of problems, reducing energy from excavation, installing physical barriers like nets and ditches, and the Rockfall Hazard Rating System used to assess slopes.
The document introduces factor of safety and probability of failure in engineering design. It discusses using sensitivity studies to systematically vary parameters over their credible ranges to determine the influence on factor of safety. This allows a more rational assessment of design risks than relying on a single calculated factor of safety. The document then provides an introduction to probability theory and statistical concepts used in probabilistic analyses, including random variables, probability distributions, sampling techniques, and calculating the probability of failure for a slope design example.
The document describes a slope stability analysis of a steep rock slope in Hong Kong located near apartment buildings. Due to heavy rains causing landslides in the 1970s, the stability of this slope was analyzed. A simple limit equilibrium model was used to calculate the factor of safety under normal conditions and during earthquakes or heavy rains. The analysis found that instability could occur if the slope became fully saturated during an earthquake. However, as earthquakes and heavy rains are unlikely to occur simultaneously, it was concluded there was no serious short-term threat to stability. Evacuation of nearby apartments was deemed unnecessary based on this short-term stability assessment.
The Rio Grande project involves a 1000 MW pumped storage hydroelectric plant located in Argentina. It provides electrical storage for the local power grid. The main underground facilities are located within high quality gneiss rock. Support requirements were assessed during excavation and minimal support was needed due to the excellent rock quality. Rockbolts and shotcrete were used as needed based on geotechnical inspection. The UNWEDGE program was utilized to analyze wedge failures and determine support requirements.
The document discusses the shear strength of discontinuities in rock masses. It defines key terms like basic friction angle (φb), residual friction angle (φr), cohesion (c), and introduces Barton's method for estimating shear strength which accounts for joint roughness coefficient (JRC) and joint compressive strength (JCS). Small scale laboratory tests are used to determine φb, while JRC and JCS are estimated visually in the field. The shear strength of rough surfaces is higher than smooth surfaces due to surface asperities. Shear strength decreases if discontinuities are filled with soft materials like clay.
This document discusses when a rock engineering design can be considered acceptable. It notes that there are no universal rules and that each design is unique based on the site conditions, loads, and intended use. Acceptability is based on engineering judgment guided by analyses and studies. Tables provide examples of typical problems, parameters, analysis methods, and acceptability criteria for different rock structures. Case histories are also discussed to illustrate the factors considered and criteria used to determine acceptability, including ensuring stability and reducing deformation. One case examines slope drainage works to improve stability of landslides in a reservoir area. Another evaluates deformation control for a power tunnel by locating a replacement in a zone of small movements.
1. The development of rock engineering began in the late 18th century, but it was not established as a formal discipline until the 1960s after several catastrophic dam failures that demonstrated limitations in predicting rock mass behavior.
2. Early contributors to rock mechanics came from various fields like soil mechanics, mining, and geology. They made important contributions to understanding rock failure even if they did not consider themselves "rock mechanics engineers".
3. Major events like dam failures and mine collapses in the 1950s and 1960s highlighted the need for rock mechanics as a discipline and led to rapid advances in methods for designing rock structures and underground excavations.
This document provides guidance on ensuring geotechnical slope stability for post-mining landforms. It discusses designing stable slopes for landforms such as low wall spoil, out-of-pit dumps, and final void batters. It emphasizes the importance of geotechnical investigations and slope design to prevent issues like lost production, safety risks, and remediation costs. Data collection should consider factors like foundation strength, slope stability, and drainage for dumped materials.
This document summarizes three articles related to previous topics in Geotechnical Instrumentation News (GIN). The first article discusses distributed optical fiber sensing, which allows continuous strain measurement along an optical fiber cable. This is useful for geotechnical applications where soil loading is non-uniform. The second article compares different technologies for strain monitoring, including distributed optical fiber sensing. The third article provides examples of using distributed optical fiber sensing to monitor strain in pile foundations and detect cracks.
This study aimed to map forest fire risk zones in Quang Ninh province, Vietnam using remote sensing and GIS. Forest fire data from MODIS and field surveys were compared to validate the analysis. Factors like forest type, proximity to roads and settlements, slope, and aspect were used as inputs to a weighted overlay analysis. This generated a risk map classifying the area into very low to very high risk zones. Most fire locations fell within high or very high risk areas, validating the model. Improving input data resolution and incorporating additional social and weather factors could enhance future analyses. The study effectively mapped forest fire risk to aid decision-making for forest management in Quang Ninh province.
This document discusses design considerations for large underground caverns excavated in weak rock at depths of 100-300m below the surface for hydroelectric projects. It addresses the stability of caverns and surrounding rock mass given in situ stress conditions, effects of nearby slopes, and determining appropriate pillar sizes between excavations. The key design factors are the strength of the rock mass, influence of structural features like joints and bedding planes, sequence of excavation and support, and stress changes induced by nearby slopes and excavations. Pillar size between caverns must consider stresses imposed and stability of the rock mass.
The document discusses rock mass properties and the Hoek-Brown failure criterion for estimating the strength of jointed rock masses. It presents the generalized Hoek-Brown criterion equation and describes how to determine the intact rock properties of uniaxial compressive strength (σci) and the Hoek-Brown constant (mi) from triaxial test data or estimates. It also discusses estimating the Geological Strength Index (GSI) of the rock mass.
This document discusses rockfall hazards and analysis. It begins with an introduction noting that rockfalls are a major hazard for mountainous transportation routes and have resulted in numerous deaths. It then discusses the mechanics of rockfalls, noting that slope geometry and surface materials are most important in determining rockfall trajectories. Various measures to reduce rockfall hazards are discussed, including identification of problems, reducing energy from excavation, installing physical barriers like nets and ditches, and the Rockfall Hazard Rating System used to assess slopes.
The document introduces factor of safety and probability of failure in engineering design. It discusses using sensitivity studies to systematically vary parameters over their credible ranges to determine the influence on factor of safety. This allows a more rational assessment of design risks than relying on a single calculated factor of safety. The document then provides an introduction to probability theory and statistical concepts used in probabilistic analyses, including random variables, probability distributions, sampling techniques, and calculating the probability of failure for a slope design example.
The document describes a slope stability analysis of a steep rock slope in Hong Kong located near apartment buildings. Due to heavy rains causing landslides in the 1970s, the stability of this slope was analyzed. A simple limit equilibrium model was used to calculate the factor of safety under normal conditions and during earthquakes or heavy rains. The analysis found that instability could occur if the slope became fully saturated during an earthquake. However, as earthquakes and heavy rains are unlikely to occur simultaneously, it was concluded there was no serious short-term threat to stability. Evacuation of nearby apartments was deemed unnecessary based on this short-term stability assessment.
The Rio Grande project involves a 1000 MW pumped storage hydroelectric plant located in Argentina. It provides electrical storage for the local power grid. The main underground facilities are located within high quality gneiss rock. Support requirements were assessed during excavation and minimal support was needed due to the excellent rock quality. Rockbolts and shotcrete were used as needed based on geotechnical inspection. The UNWEDGE program was utilized to analyze wedge failures and determine support requirements.
The document discusses the shear strength of discontinuities in rock masses. It defines key terms like basic friction angle (φb), residual friction angle (φr), cohesion (c), and introduces Barton's method for estimating shear strength which accounts for joint roughness coefficient (JRC) and joint compressive strength (JCS). Small scale laboratory tests are used to determine φb, while JRC and JCS are estimated visually in the field. The shear strength of rough surfaces is higher than smooth surfaces due to surface asperities. Shear strength decreases if discontinuities are filled with soft materials like clay.
This document discusses when a rock engineering design can be considered acceptable. It notes that there are no universal rules and that each design is unique based on the site conditions, loads, and intended use. Acceptability is based on engineering judgment guided by analyses and studies. Tables provide examples of typical problems, parameters, analysis methods, and acceptability criteria for different rock structures. Case histories are also discussed to illustrate the factors considered and criteria used to determine acceptability, including ensuring stability and reducing deformation. One case examines slope drainage works to improve stability of landslides in a reservoir area. Another evaluates deformation control for a power tunnel by locating a replacement in a zone of small movements.
1. The development of rock engineering began in the late 18th century, but it was not established as a formal discipline until the 1960s after several catastrophic dam failures that demonstrated limitations in predicting rock mass behavior.
2. Early contributors to rock mechanics came from various fields like soil mechanics, mining, and geology. They made important contributions to understanding rock failure even if they did not consider themselves "rock mechanics engineers".
3. Major events like dam failures and mine collapses in the 1950s and 1960s highlighted the need for rock mechanics as a discipline and led to rapid advances in methods for designing rock structures and underground excavations.
This document provides guidance on ensuring geotechnical slope stability for post-mining landforms. It discusses designing stable slopes for landforms such as low wall spoil, out-of-pit dumps, and final void batters. It emphasizes the importance of geotechnical investigations and slope design to prevent issues like lost production, safety risks, and remediation costs. Data collection should consider factors like foundation strength, slope stability, and drainage for dumped materials.
This document summarizes three articles related to previous topics in Geotechnical Instrumentation News (GIN). The first article discusses distributed optical fiber sensing, which allows continuous strain measurement along an optical fiber cable. This is useful for geotechnical applications where soil loading is non-uniform. The second article compares different technologies for strain monitoring, including distributed optical fiber sensing. The third article provides examples of using distributed optical fiber sensing to monitor strain in pile foundations and detect cracks.
This study aimed to map forest fire risk zones in Quang Ninh province, Vietnam using remote sensing and GIS. Forest fire data from MODIS and field surveys were compared to validate the analysis. Factors like forest type, proximity to roads and settlements, slope, and aspect were used as inputs to a weighted overlay analysis. This generated a risk map classifying the area into very low to very high risk zones. Most fire locations fell within high or very high risk areas, validating the model. Improving input data resolution and incorporating additional social and weather factors could enhance future analyses. The study effectively mapped forest fire risk to aid decision-making for forest management in Quang Ninh province.