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Abstract: During the feasibility and preliminary design stages of a project, when very little detailed information on the rock mass and its geomechanic characteristics is not available, the use of a Rock Mass Classification Scheme (RMCS) can be of considerable benefit. Various parameters were used in order to identify the RMCS. The parameter comprised of Rock Quality Designation (RQD), Rock Mass Rating (RMR), Rock Structure Rating (RSR), Geological Strength Index (GSI), Slope Mass Rating (SMR), etc. In this paper, we present the results of the applicability of the Geological Strength Index (GSI) classification for the Trusmadi Formation in Sabah, Malaysia. The GSI classification system is based on the assumption that the rock mass contains a sufficient number of “randomly” oriented discontinuities such that it behaves as a homogeneous isotropic mass. In this study, the GSI relates the properties of the intact rock elements/blocks to those of the overall rock mass. It is based on an assessment of the lithology, structure and condition of discontinuity surfaces in the rock mass and is estimated from visual examination of the rock mass exposed in outcrops or surface excavations. A total of ten (10) locations were selected on the basis of exposures of the lithology and slope condition of the Trusmadi Formation. The Trusmadi Formation regionally experienced of two major structural orientations NW-SE and NE-SW. It consists mostly of dark grey shale with thin bedded sandstones, typical of a turbidite deposit. This unit has been subjected to low grade of metamorphism, producing slates, phyllites and meta-sediments and intense tectonic deformation producing disrupted or brecciated beds. Quartz vein are quite widespread within the joints on sandstone beds. The shale is dark grey when fresh but changes light grey to brownish when weathered. The results are classified as “Poor Rock” to “Fair Rock” in term of GSI. The poor categories (TR2 and TR7) represent slickensided, highly weathered surfaces with compact coatings or fillings or angular fragments. It is also characterized as blocky/ disturbed/seamy, which folded with angular blocks formed by many intersecting discontinuity sets. The fair categories can be divided into two (2) types; type 1 (TR1, TR6 and TR8) which represent as smooth, moderately weathered and have altered surfaces. It is also characterised as very blocky rock, which indicates interlocked, partially disturbed ass with multi-faceted angular blocks formed by 4 or more joint sets. Type 2 (TR3, TR4, TR5, TR9 and TR10) which represent as smooth, moderately weathered and have altered surfaces but characterized as blocky/disturbed/seamy, which folded with angular blocks formed by many intersecting discontinuity sets. It also has persistence of bedding planes or schistosity.  Mar 17, 2022, 10:08 PM jeffery jim
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Abstract: Rock Mass Classification Systems (RMCS) can be of considerable use in the initial stage of a project when little or no detailed information is available. There is a large number of RMCS developed for general purposes but also for specific applications such as Rock Quality Designation (RQD), Rock Mass Rating (RMR), Rock Structure Rating (RSR), Geological Strength Index (GSI), Slope Mass Rating (SMR), etc. In this paper, we present the results of the applicability of the Rock Mass Rating (RMR) System for the Trusmadi Formation in Sabah, Malaysia. The RMR system is a RMCS incorporated with five (5) parameters: Strength of intact rock material, Rock Quality Designation (RQD), Spacing of joints, Condition of joints, and Groundwater conditions. A total of ten (10) locations were selected on the basis of exposures of the lithology and slope condition of the Trusmadi Formation. Trusmadi Formation is Paleocene to Eocene in aged. The Trusmadi Formation generally shows two major structural orientations NW-SE and NE-SW. Trusmadi Formation is characterized by the present of dark colour argillaceous rocks, siltstone and thin-bedded turbidite in well-stratified sequence. Some of the Trusmadi Formation rocks have been metamorphosed to low grade of the greenish-schist facies; the sediment has become slate, phyllite and metarenite. Cataclastic rocks are widespread and occur as black phyllonite enclosing arenitic and lutitic boudins with diameter up to a meter or demarcating thin to thicker fault zones or as flaser zones with hardly any finer grain matrix or as zones of closely spaced fractures. Quartz and calcite veins are quite widespread within the crack deformed on sandstone beds. The shale is dark grey when fresh but changes light grey to brownish when weathered. The RMR system for 10 outcrops ranges from 33.0 to 50.0 and its classified as “Fair” (Class III) to “Poor” (Class IV) rocks. The Fair Rock (Class III) recommended that the excavation should be top heading and bench 1.5 m – 3 m advance in the top heading. Support should be commencing after each blast and complete support 10 m from face. Rock bolts should be systematic with 4 m long spaced 1.5 m - 2 m in crown and walls with wire mesh in crown. Shotcrete should be 50 mm – 100 mm in crown and 30 mm in sides. While for the Poor Rock (Class IV), the excavation should be top heading and bench 1.0 m – 1.5 m advance in top heading. Support should be installed concurrently with excavation, 10 m from face. Rock bolt should be systematic with 4 m – 5 m long, spaced 1.5 m – 1.5 m in crown and walls with wire mesh. Shotcrete of 100 m – 150 mm in crown and 100 mm in sides. The steel sets should be light to medium ribs spaced 1.5 m only when required.  Mar 17, 2022, 10:09 PM jeffery jim
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In most structural repair works or building condition assessment, structural appraisal has been done through visual inspection for tell-tale signs which highlight the possible defect. This method is extended to the standard guideline by Jabatan Kerja Raya (JKR) in their BCA format in determining the physical condition rating. Consulting engineers or structural specialists are to participate when it is determined that the structure requires material testing in order to come up with diagnoses and prognosis. The use of descriptive statistics in both reconnaissance or desktop studies as well as in standard specifications have limitation in determining the actual structural issues. This study demonstrates the advantages of using Multivariate Statistical Analysis (MVA) in summating the right diagnosis and prognosis for structural repair works.  Mar 27, 2022, 8:13 AM jeffery jim
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Abstract: In the recent years, the impacts of floods have gained importance because of the increasing number of people who are affected by its adverse effects, especially in Beaufort area, Sabah, Malaysia. Flood destroyed critical infrastructures that are needed as shelter and also emergency relief for victim. This paper presents the findings of flood modelling undertaken to establish baseline and post mining flooding conditions during upstream storm and combination of upstream and downstream storm, respectively. A hydrologic model was established and calibrated based on 2014 flood. A structural approach by changing the physical dimension through dredging or sand mining between 2m to 3m is used for hydrology modelling is added into the existing floodgates and bunds. The outcome from sustainable sand is prevailing when it is able to reduce flood level for normal flow, upstream case, and both upstream and downstream case. Other findings are changes in velocity, shear and the significantly reduced power generated by the river during flooding.  Mar 17, 2022, 10:07 PM jeffery jim
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Abstract: At present, most academics and practitioners only make assumptions or simplistic correlation between soils in Sabah, Malaysia and soils in West Malaysia in order determine the Soil Erodibility Factor for Erosion and Sedimentation Control Plan (ESCP) submission apart from using The Soils of Sabah, Volume 5 which is rather archaic or obsolete. This study shall be the foundation for moves to build up databank for Department and Irrigation Drainage (DID) Sabah, Malaysia based on soil taxonomy for erosion and sedimentation control calculations. In term of environmental control application, this research provides specific required information in order to generate precise calculation in projecting the total sediment yield for ESCP for areas around the West Coast of Sabah. Findings of the study would benefit both academicians and ESCP practitioners in generating sediment yield based on Soil Map of Sabah.  Mar 17, 2022, 10:06 PM jeffery jim
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