Determining the Appropriate Sealing Conditions through a Permeability and Groutability Evaluation: A Case Study of Sivaki Dam, Iran

2021 ◽  
pp. qjegh2020-124
Author(s):  
Mohammad Javad Kalantar Hormozi ◽  
Akbar Ghazifard ◽  
Zeinab Jorkesh
Keyword(s):  
Rock Mass ◽  
Grout Curtain ◽  
High Strength ◽  
Earth Dam ◽  
Geological Strength Index ◽  
Construction Site ◽  
Cutoff Wall ◽  
Lugeon Test ◽  
Asmari Limestone

The Sivaki Dam is an earth dam that is located near Yasuj city, 5.3 km northwest of Sepidar village. During excavations at the dam construction site, the high potential of water seepage from the foundation and its abutments has been proven. Some cavities and dissolution have been observed on both sides of the dam, suggesting the possibility of Karstification at greater depths. Most of the outcropping rocks in the study area comprise Asmari Limestone. These rock masses, despite their medium to high strength, have provided unfavorable conditions in terms of permeability and weathering. In this study, the foundation and both abutments of the dam were evaluated and analyzed to determine the permeability and groutability characteristics. To achieve this goal, the engineering characteristics of the rock mass of the construction site were examined by performing rock mass rating (RMR) and geological strength index (GSI) classifications. Moreover, the Lugeon test, secondary permeability index (SPI), rock quality designation (RQD), and monitoring hydraulic flows were used for this purpose. According to the results of this study, for abutments of the dam and in the case of alluvial substrates, grout curtain and the cutoff wall are respectively the best and most compatible methods available.

scholarly journals Analysis of engineering geology conditions based on the quality of rock mass in the Tiga Dihaji Dam’s diversion tunnel, South Sumatera, Indonesia

2021 ◽  
Vol 325 ◽  
pp. 05001
Author(s):  
Zekrinaldi ◽  
Ferian Anggara ◽  
Hendy Setiawan
Keyword(s):  
Rock Mass ◽  
Geological Strength Index ◽  
Strength Index ◽  
Diversion Tunnel ◽  
Rock Mass Quality ◽  
Geological Conditions ◽  
Q System

This research has examined the rock mass quality case study in the Tiga Dihaji Dam’s diversion tunnel. Observations of geological conditions were carried out on the surface and subsurface of the study site and show that the study area consists of tuffaceous sandstone and carbonate interbeds. The method of this study is based on the classification of the Geological Strength Index (GSI), Rock Mass Rating (RMR), and the Q-system. The results indicate that tuffaceous sandstone has a GSI value of 15 - 87.5 (very poor - very good), RMR 48 - 82 (fair - very good), and Q-system 0.01 – 60.0 (exceptionally poor - very good). Meanwhile, carbonate interbeds have a low value, with a GSI value of 10.5 - 77.5 (very poor to very good), RMR 17.0 – 56.0 (very - poor fair), and Q-system 0 - 35.2 (exceptionally poor - good). Moreover, a correlation was made between rock mass quality for conditions in the study area. The correlation between GSI and RMR was obtained by the equation GSI = 2.2885RMR 82.567 (R2 = 0.6653), RMR and Q-system RMR = 2.0175ln(Q) + 63.061 (R2 = 0.4987), and GSI and Q-system GSI = 7.2119ln(Q) 54.578 (R2 = 0.8095).

A CASE STUDY FOR EXAMINATION OF EFFECTIVENESS OF THE SAFEGUARDING SUPPORTIVE SYSTEM AT A TUNNEL CONSTRUCTION SITE

2019 ◽  
Vol 75 (2) ◽  
pp. I_99-I_107
Author(s):  
Shoken SHIMIZU ◽  
Junichiro YONETAKE ◽  
Takahiko SHOBU ◽  
Makoto IMAI ◽  
Shinichi YAMAMOTO ◽  
...  
Keyword(s):  
Tunnel Construction ◽  
Construction Site

scholarly journals Design Optimization of Explosion-Resistant System Consisting of Steel Slab and CFRP Frame

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2589
Author(s):  
Jung J. Kim
Keyword(s):  
Hybrid System ◽  
Impact Load ◽  
Load Condition ◽  
High Strength ◽  
Dynamic Responses ◽  
Elastoplastic Behavior ◽  
Reinforced Polymer ◽  
Steel Slab ◽  
Strength Material

This study presents an explosion-resistant hybrid system containing a steel slab and a carbon fiber-reinforced polymer (CFRP) frame. CFRP, which is a high-strength material, acts as an impact reflection part. Steel slab, which is a high-ductility material, plays a role as an impact energy absorption part. Based on the elastoplastic behavior of steel, a numerical model is proposed to simulate the dynamic responses of the hybrid system under the air pressure from an explosion. Based on this, a case study is conducted to analyze and identify the optimal design of the proposed hybrid system, which is subjected to an impact load condition. The observations from the case study show the optimal thicknesses of 8.2 and 7 mm for a steel slab and a ϕ100 mm CFRP pipe for the hybrid system, respectively. In addition, the ability of the proposed hybrid system to resist an uncertain explosion is demonstrated in the case study based on the reliability methodology.

scholarly journals Study of Rock Mass Rating (RMR) and Geological Strength Index (GSI) Correlations in Granite, Siltstone, Sandstone and Quartzite Rock Masses

2021 ◽  
Vol 11 (8) ◽  
pp. 3351
Author(s):  
Gabor Somodi ◽  
Neil Bar ◽  
László Kovács ◽  
Marco Arrieta ◽  
Ákos Török ◽  
...  
Keyword(s):  
Rock Mass ◽  
Linear Equations ◽  
Geological Strength Index ◽  
Gold Mine ◽  
Strength Index ◽  
Comprehensive Understanding ◽  
Rock Types ◽  
Mass Classification ◽  
Waste Repository ◽  
And Performance

A comprehensive understanding of geological, structural geological, hydrogeological and geotechnical features of the host rock are essential for the design and performance evaluation of surface and underground excavations. The Hungarian National Radioactive Waste Repository (NRWR) at Bátaapáti is constructed in a fractured granitic formation, and Telfer Gold Mine in Australia is excavated in stratified siltstones, sandstones and quartzites. This study highlights relationships between GSI chart ratings and calculated GSI values based on RMR rock mass classification data. The paper presents linear equations for estimating GSI from measured RMR89 values. Correlations between a and b constants were analyzed for different rock types, at surface and subsurface settings.

scholarly journals Influence of the groundwater level on the bearing capacity of shallow foundations on the rock mass

2021 ◽  
Author(s):  
Ana Alencar ◽  
Rubén Galindo ◽  
Svetlana Melentijevic
Keyword(s):  
Rock Mass ◽  
Bearing Capacity ◽  
Groundwater Level ◽  
Sensitivity Study ◽  
Shallow Foundations ◽  
Unit Weight ◽  
Geological Strength Index ◽  
Strength Index ◽  
Mass Type

AbstractThe presence of the groundwater level (GWL) at the rock mass may significantly affect the mechanical behavior, and consequently the bearing capacity. The water particularly modifies two aspects that influence the bearing capacity: the submerged unit weight and the overall geotechnical quality of the rock mass, because water circulation tends to clean and open the joints. This paper is a study of the influence groundwater level has on the ultimate bearing capacity of shallow foundations on the rock mass. The calculations were developed using the finite difference method. The numerical results included three possible locations of groundwater level: at the foundation level, at a depth equal to a quarter of the footing width from the foundation level, and inexistent location. The analysis was based on a sensitivity study with four parameters: foundation width, rock mass type (mi), uniaxial compressive strength, and geological strength index. Included in the analysis was the influence of the self-weight of the material on the bearing capacity and the critical depth where the GWL no longer affected the bearing capacity. Finally, a simple approximation of the solution estimated in this study is suggested for practical purposes.

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