Developing Engineering Geological Model from Resistivity (ERT) Surveys: Several Case Studies from Malaysia

( Farid Dali ),( Abd Rasid Jaapar ),( Zakaria Mohamad ),( Afiq Farhan Abdul Rahim ),( Mohamad Faruq Syahmi Md Aripin ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Electrical Resistivity survey has been commonly used to investigate the anomalies of subsurface ground condition. Tomographic Pseudo section model presents the different range of resistivity value, indicating variation of soil layers, occurrence of groundwater, boulders or fractured bedrock zones. The complexity of subsurface geomaterials profile due to structural geology and weathering leads to potential inaccuracies in intrepetation without substantial geological input. Therefore, engineering geological model generated from subsurface electrical resistivity survey, combined with borehole and field observation input is very important to present the subsurface condition of the area. Thirteen (13) electrical resistivity survey lines were set up established at three (3) sites located at Selangor (Site A), Kuala Lumpur (Site B) and Negeri Sembilan (Site C). The objectives of these investigations are: to investigate potential geohazards near residential areas (Site A), to investigate the existence of subsurface boulders/rocks fragments that will affect the design and cost of geotechnical construction (Site B) and to investigate the incidence of displacement of water tank that exceeds allowable movement due to ground movement. A reliable geological interpretation presented in form of engineering geological model was utilized by geotechnical engineers/decision makers to solve construction and geohazards issues. It helps to visualize or summarize the outcome of any geological investigation tools in simplest way especially to non-geologist.

Technical Innovation of Engineering Geology----idea and practice

( Faquan Wu ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

We don’t worry about theory, but we concern technology because it is lagged far behind the requirements of the industry! It is the time for the integrated innovation of technology in engineering geology since the blowout-like High-techs and Cool-techs and rich experiences of new tech applications. An idea is to be proposed for an action on technical innovation aiming at more convenient and intelligent engineering geological work. There have been rich practices in the industry of engineering geology for different purposes, covering mapping, prospection, testing, monitoring and designing technology. Portable laboratory, non-contacting measuring and massif digitalizing; cloud calculating, process simulating and IoT based monitoring, and technical standard renovation will promote and support this industrial innovation.

Reconnoitering Issues of Himalayan Engineering Geology in Recent Context of Infrastructure Development

( Ranjan Kumar Dahal ),( Shuichi Hasegawa ),( Manita Timilsina ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The Himalaya is the highest mountain range of the globe which has been formed by the collision of India and Eurasia plates. The Nepal Himalaya is well defined in various geological zones from the beginning, but the engineering geological significance of each geological zone is not well understood. As a result, engineering geological issues in the Nepal Himalaya during infrastructure development are prime concerns for planners. Convergence and shear zones in tunnels of hydropower projects, cut slopes failures in highways and canal embankment failures are recent hot news in local newspapers. Likewise, various thrust systems in the Nepal Himalaya are always considered as critical zones for infrastructure construction and many projects are abandoned only due to the presence of Main Central Thrust (MCT), or Main Boundary Thrust (MBT) or Main Frontal Thrust (MFT) in the project site. However, on the other hand, it is confirmed that movements in MCT and MBT were ceased nearly 6 and 1 Ma ago respectively. Movement frequency along MFT is also believed to be more than few hundred years and seismic activities along MFT are also not the same in whole Nepal. Similarly, the largescale landslide on the Midland and Lesser Himalayan regions has produced crushed rock mass and slope can be excavated easily without blasting which cannot be a common scenario in hard rock geology. This presentation will describe all these issues with field data and case histories.

Land and Sea Engineering Geological Model and Division of the Laizhou Bay Coast, China

( Xiaoshuai Song ),( Yonggang Jia ),( Hongxian Shan ),( Xiaolei Liu ),( Yong Zhang ),( Xianghuai Kong ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

In order to meet the development demands of Laizhou Bay Coastal Zone, there has carried out, including engineering survey, engineering geological drilling, in-situ test (standard penetration test), laboratory test, theoretical analysis and other research methods, in line with the layout of geo-spatial development and its geological environment characteristics. Through the analysis of the essential data, the stratigraphic structure, topography, geological structure and hydrogeological conditions of the study area were obtained. Based on the measured data of 24 engineering geological boreholes and the collected data of 202 boreholes, nine engineering geological layers were determined. And the types of rock and soil, the distribution of poor geological bodies and the engineering geology structural features have been understood. Based on that, the three-dimensional engineering geological model of Laizhou Bay coastal zone was established by using the software Mapgis K9. The image of the model objectively reflected the engineering stratigraphic structure and geological characteristics of the study area. Finally, the land area of the study area was divided into three major engineering geological areas and eight engineering geological sub-areas. Similarly, the sea area was divided into three major areas and six geological sub-areas. This work can provide local government with detailed and reliable basic data for development planning, provide scientific basis for coastal economic construction and sustainable development, and serve land and resources utilization, coastal zone development and management and planning.

Comprehensive Engineering Geological Assessment of a Landslide Prone Section of Proposed New Urban Highway in Kuala Lumpur, Malaysia

( Afiq Farhan Abdul Rahim ),( Abd Rasid Jaapar ),( Muhammad Farid Mohamed Dali ),( Mustapha Atta ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Hilly areas to the east and north of Kuala Lumpur are known to be prone to landslide incidents as recorded in numerous historical cases involving life and property loss. Most historical incidence have been attributed to lack of proper planning and investigations, especially in terms of geology, engineering geology and geomorphological aspects. Therefore, this study aims to set up a good practice example in comprehensive engineering geological assessment - in this case, for a proposed urban highway at eastern Kuala Lumpur - along an engineering geologically challenging terrain. This study consists of the following components; terrain mapping (geomorphological study) and geohazards assessments along highway alignment to identify potential geotechnically challenging section, and geophysical survey with engineering geological assessment on specific identified sections to identify specific engineering geological issues. Lithology, structural geology and weathering profile are among factors identified contributing to issues in the study area which will affect construction and post-construction activities of the highway. The engineering geological assessment and model output from this study will be utilized for subsequent geotechnical works and stabilization design, which would address the challenges and any potential landslide in the region.

Urban geology of Tabriz City: Environmental and geological constraints

Azarafza, Mohammad,Ghazifard, Akbar Techno-Press 2016 Advances in environmental research Vol.5 No.2

Urban geology is the study of urban geologic environments to provide a scientific basis for rational land use planning and urban development and provides information on geologic environments as a basis for city planners. Based on AEG recommendations, urban geological studies covered the urbanism and historical backgrounds, geological setting, engineering geological constraints and environmental assessments of understudied cities. The aim of this study is to provide a good view of urban geology of Tabriz city the capital of East Azerbaijan province in Iran. The topics of discussions about Tabriz city urban geology are included geologic (geomorphology, geology, climatology and hydrogeology), engineering geological (earthquake, landslide and geotechnical hazards investigations) and environmental characteristics (air, soil and water hazards assessment).The results of the urban geologic studies indicated that Tabriz city in terms of engineering geological and environmental constraints is at high risk potential and in terms of seismic activity and landslide instability is highly potential. In terms of air, soil and water pollution there are many important environmental concern in this city.

From Field to Engineering Geological Conceptualization - A Case Study in Apothikes, Santorini, Greece

( Efstratios Karantanellis ),( Ioakeim Konstantinidis ),( Vassileios Marinos ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Nowadays, the implementation of high-end technology (UAV, LiDaR) in engineering geology, combined with a solid geo-engineering background of the researcher, could lead to realistic and accurate conceptual models. In this case study, an engineering geological conceptual model of “Apothikes”, Santorini island, Greece has been constructed. The construction is based on UAV derived 3D mesh and in-situ observational methods, integrating the advantages of innovative remote sensing technologies and enhancing traditional field mapping methods. The investigated site is located across the road network that leads to the only beach that lays inside the caldera region. The area is geologically characterized by alternations of volcanic beds of strong ignimbrite and soft layers of pyroclastic tuffs. These different engineering properties of the materials combined with the very steep morphology and the vertical dip persistent discontinuities constitute to differential erosion and undercut in the base of the slope. Tensile tenses developed and eventually lead to rock pillar detachment followed by toppling or planar sliding failure of the previously suspended blocks of ignimbrite from a notable height (□ 20m). The significance of this specific region originates from the noteworthy human presence in the prone areas. Consequently, it is indispensable to provide precise precognitions of potential rockfall hazard via adequate visualization, which was achieved by constructing a detailed 3D observational model. It gives us confidence, that through this in-depth 3D risk assessment we can propose specific remedial measures and mitigate their potential miscarriages. This study demonstrates that, conceptual models could be considered as valuable supplemental tools in geo-engineering.

Fostering the Use of Innovative Remote Sensing Techniques in Engineering Geology

( Janusz Wasowski ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

Innovative remote sensing technologies e.g., sub-0.5 m resolution, daily image capacity optical satellite constellations, UAV and LiDAR, can provide imagery suitable for producing detailed (“engineering scale”) topographic maps and DEM. High precision measurements of ground surface and infrastructure deformations can also be obtained. Satellite radar sensors and advanced InSAR techniques offer great potential for multi-scale (from regional scale to site-specific) deformation monitoring thanks to wide-area coverage, regular schedule with increasing re-visit frequency, while maintaining high spatial resolution and millimetre precision of measurement. Furthermore, with the improved digital image processing techniques we now have a capability of delivering more rapidly high quality information that is useful (and cost-effective) for many engineering applications, both in research and practice. For example, remotely sensed data can assist in: - terrain mapping (e.g., for lifeline routing) - site selection and characterization - geohazards assessment and monitoring (e.g., wide-area subsidence, local settlements, slope instability/landslides) - monitoring human-induced land instability (e.g., subsidence due to ground water withdrawal) - monitoring engineering structures (e.g., stability of transportation infrastructure, dams) - monitoring mining operations (e.g., slope instability issues in open cast mines) - monitoring and management of oil/gas field operations (e.g., addressing ground instability issues) - rapid engineering structure damage assessment (e.g. building structural damage after an earthquake) However, engineering geologists typically have limited knowledge of new remote sensing technologies. Therefore, a greater opening of the profession to closer multi-disciplinary collaborations is necessary to fully benefit from the big data that innovative remote sensing can now produce.

Fit for Purpose 3D Engineering Geological Modelling

( Richard Brehaut ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

This presentation describes the engineering geological model from three projects in the civil infrastructure and construction industries; a highway tender design, a dam design study and a construction phase model for use during tunnel excavation. Typically, tender models have limited data where scripts can interpolate between widely spaced boreholes to develop project-scale three-dimensional surfaces (eg weathering profiles) which are used to inform concept designs and project budgeting. While these models appear to offer continuous project coverage, any output must be accompanied by documentation capturing modelling assumptions/limitations. In contrast, dam design projects benefit from detailed data sources backed by focused site investigation with excellent spatial coverage. Model development often benefits from sufficient time and resources allowing the model to be well calibrated; resulting in high-resolution imagery and powerful three-dimensional elements that can be queried and interrogated offering increased value to numerous stakeholders. Three-dimensional engineering geological models developed within an active construction environment offer reproduction of encountered conditions in a format suitable for quick decision making. Geotechnical field mapping provides an intricate understanding of ground conditions but can be difficult to visualise in two-dimensions. Georeferencing maps and plans together with delineation of specific geological structures in three-dimensions can critically inform key engineering decisions in changing conditions within tight construction schedules. This presentation will compare and contrast three-dimensional models developed for these different studies, illustrating how the confidence and reliability of the model changes based on the needs of the project and the difficulties in communicating these factors as part of the model.

Engineering Geological and Geotechnical Investigation of Landslide in Region of Zvare, Central Georgia, Alongside to New Railway Line

( Levan Maisuradze ),( Vasilios Marinos ),( Nikolaos Kazilis ) 대한지질공학회 2019 대한지질공학회 학술발표회논문집 Vol.2019 No.2

The current study deals with slope instability at the wider area of Zvare village, of Imereti region, central Georgia, central Caucasus, adjacent to railroad alignment. Conceptual engineering geological model was created in order understand better the behavior of the ground, so investigations in terms of Surface geological mapping, drilling and boring, laboratory tests and geotechnical monitoring was carried out. The landslide, of approximately 400m length and 230m wide, was activated at 13/05/2017 at the above mentioned region, due to excavations, which were carried out at the toe of old stabilized landslide, for the construction of railroad line. The mentioned landslide, although constitutes a complex system of minor landslides, generally is classified as a rotational andslide. Displacements approach 16m in lateral direction and 7m in vertical, respectively. The maximum depth of shearing due to boring and instrumentation, is estimated at depth of 40m, which through to back analysis shown shear strength of shear surface, expressed as Mohr Coulomb shear parameters, cohesion c=0 and friction angle φ=10°. This failure provides several geotechnical and social related problems. These deal with the safe construction and maintnanance of the new railway line, the maintenance of the river and the road. In addition, one main issue is the maintenance of the springs of natural carbonated water, which are also located at the left bank of the river. The area of springs is considered protected area.