scholarly journals Excavation Method Implemented in Atal (Rohtang) Tunnel: Case Study

2021 ◽  
Vol 9 (VII) ◽  
pp. 1065-1068
Author(s):  
Verma Aakash
Keyword(s):  
Rock Mass ◽  
Shear Zones ◽  
Himachal Pradesh ◽  
Steel Pipe ◽  
Mechanical Methods ◽  
Geotechnical Investigations ◽  
Excavation Support

Structurally dynamic, youthful collapsed mountains; The Himalayas are loaded with full of geological surprises, involving issues, folds, shear zones and so forth that shows their quality because of progressing structural exercises in the Himalayas. In feature of Atal tunnel, these issues increments multifold due to high overburden of the material and also careful topographical and geotechnical investigations at different scales. This makes vulnerability in planning a specific emotionally supportive network and requests for "structure as you go" approach for whole passage length (8.8km). DRESS (Drainage-Reinforcement-Excavation-Support-Solution) philosophy of excavation is very powerful in water bearing issue zones of delicate Himalayan district. DRESS includes pre-seepage of ground in front of face with long waste gaps and adjustment of the crown in front of passage face by steel pipe umbrella curve, up to a foreordained length, trailed by exhuming in little strides by mechanical methods and backing thereof. Numerous troublesome issues have been experienced during construction which was unpredicted initially. One such issue is an experience of Seri Nala. Due to differing conduct of rock mass, continuous update of rock mass is constantly required. NATM is dependent on disfigurement observing information to assess amount and nature of emotionally supportive network, has end up being a fitting apparatus for tunneling in the youthful Himalayas. This paper depicts the consolidation of NATM as well as DRESS method in the unearthing of Atal Tunnel, Himachal Pradesh, India

scholarly journals Engineering geological and geotechnical investigations of dam of the Bunakha Hydroelectric Project (180 MW), Chukha Dzong, Bhutan Himalaya

2014 ◽  
Vol 47 (1) ◽  
pp. 77-94 ◽  
Author(s):  
A. K. Naithani ◽  
P. C. Nawani ◽  
L. G. Singh ◽  
D. S. Rawat
Keyword(s):  
Rock Mass ◽  
Shear Zones ◽  
Geological Mapping ◽  
Engineering Properties ◽  
Concrete Gravity Dam ◽  
Hydroelectric Project ◽  
Laboratory Test Results ◽  
Geotechnical Investigations ◽  
Tehri Dam

A 197 m high roller compacted concrete gravity dam is proposed across river Wang Chhu in Chukha Dzong of the Bhutan Himalaya. Bunakha Dam will be the third highest dam constructed by India after the Tehri Dam and Bhakra Dam. The Bunakha Dam site area is located in the Thimpu Formation of the Himalayan crystalline complex. This litho-units at site is characterized by heterogeneous lithology consisting of viz.  banded gneisses, foliated gneisses, with large boudins and bands of quartzite and calc-silicate gneisses with large porphyroblasts of garnet measuring up to 4 mm. These litho units form the foundation of proposed dam. In this paper attempt has been made to bring out the rock mass condition of the foundation of dam of the proposed scheme on the basis of detailed engineering geological mapping, geological logging of drill holes, rock mass permeability values, 3D mapping of exploratory drifts, geophysical profiling, in-situ and laboratory test results. Rock mass classification using Rock Mass Rating (RMR) system and Q-system was done. The basic purpose of these investigations was to identify/map different rocks and structures like joints, shear zones, faults, fracture zones etc. and to determine engineering properties of rock and rock mass by lab and in-situ testing and to provide basic data for economic and fail-safe design of the dam. On the basis of these investigations suitable recommendations have been made which will be helpful during the construction of the dam. 

scholarly journals A Case Study of a Large Unstable Mass Stabilization: “El Portalet” Pass at the Central Spanish Pyrenees

2021 ◽  
Vol 11 (16) ◽  
pp. 7176
Author(s):  
Guillermo Cobos ◽  
Miguel Ángel Eguibar ◽  
Francisco Javier Torrijo ◽  
Julio Garzón-Roca
Keyword(s):  
Water Table ◽  
Critical Factor ◽  
Slope Stabilization ◽  
Survey Techniques ◽  
Geotechnical Investigations ◽  
Spanish Pyrenees ◽  
Parking Lot ◽  
Unstable Slope ◽  
Total Stability

This case study presents the engineering approach conducted for stabilizing a landslide that occurred at “El Portalet” Pass in the Central Spanish Pyrenees activated due to the construction of a parking lot. Unlike common slope stabilization cases, measures projected here were aimed at slowing and controlling the landslide, and not completely stopping the movement. This decision was taken due to the slow movement of the landslide and the large unstable mass involved. The degree of success of the stabilization measures was assessed by stability analyses and data obtained from different geotechnical investigations and satellite survey techniques such as GB-SAR and DinSAR conducted by different authors in the area under study. The water table was found to be a critical factor in the landslide’s stability, and the tendency of the unstable slope for null movement (total stability) was related to the water table lowering process, which needs more than 10 years to occur due to regional and climatic issues. Results showed a good performance of the stabilization measures to control the landslide, demonstrating the effectiveness of the approach followed, and which became an example of a good response to the classical engineering duality cost–safety.

Geological significance of soil gas radon: A case study of Nurpur area, district Kangra, Himachal Pradesh, India

2006 ◽  
Vol 41 (4) ◽  
pp. 482-485 ◽  
Author(s):  
Surinder Singh ◽  
Dinesh Kumar Sharma ◽  
Sunil Dhar ◽  
Surjit Singh Randhawa
Keyword(s):  
Himachal Pradesh ◽  
Soil Gas ◽  
Geological Significance ◽  
Soil Gas Radon

Application of ABAQUS in Surrounding Rock Stability Analysis of Shallow Large Cross-Section Tunnel

2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strong Support ◽  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
Rock Bolting ◽  
Excavation Support ◽  
The Stability

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.

Implementation of InfraRed Thermographic surveys in complex coastal areas: the case study of Polignano a Mare (southern Italy)

2021 ◽  
Author(s):  
Lidia Loiotine ◽  
Marco La Salandra ◽  
Gioacchino Francesco Andriani ◽  
Eliana Apicella ◽  
Michel Jaboyedoff ◽  
...  
Keyword(s):  
Rock Mass ◽  
Structure From Motion ◽  
Southern Italy ◽  
Thermal Imager ◽  
Rock Masses ◽  
Field Surveys ◽  
Thermal Images ◽  
Thermal Anomalies ◽  
Rock Face

<p><em>InfraRed Thermography</em> (IRT) spread quickly during the second half of the 20<sup>th</sup> century in the military, industrial and medical fields. This technique is at present widely used in the building sector to detect structural defects and energy losses. Being a non-destructive diagnostic technique, IRT was also introduced in the Earth Sciences, especially in the volcanology and environmental fields, yet its application for geostructural surveys is of recent development. Indeed, the acquisition of thermal images on rock masses could be an efficient tool for identifying fractures and voids, thus detecting signs of potential failures.<br>Further tests of thermal cameras on rock masses could help to evaluate the applicability, advantages and limits of the IRT technology for characterizing rock masses in different geological settings.<br>We present some results of IRT surveys carried out in the coastal area of Polignano a Mare (southern Italy), and their correlation with other remote sensing techniques (i.e. <em>Terrestrial Laser Scanning</em> and <em>Structure from Motion</em>). The case study (<em>Lama Monachile</em>) is represented by a 20 m-high cliff made up of Plio-Pleistocene calcarenites overlying Cretaceous limestones. Conjugate fracture systems, karst features, folds and faults, were detected in the rock mass during field surveys. In addition, dense vegetation and anthropogenic elements, which at places modified the natural setting of the rock mass, represent relevant disturbances for the characterization of the rock mass. In this context, IRT surveys were added to the other techniques, aimed at detecting the major discontinuities and fractured zones, based on potential thermal anomalies. <br>IRT surveys were carried out in December 2020 on the east side of the rock mass at <em>Lama Monachile</em> site. Thermal images were acquired every 20 minutes for 24 hours by means of a FLIR T-660 thermal imager mounted on a fixed tripod. Ambient air temperature and relative humidity were measured during the acquisition with a pocketsize thermo-hydrometer. A reflective paper was placed at the base of the cliff to measure the reflected apparent temperature. In addition, three thermocouple sensors were fixed to the different lithologic units of the rock face. These parameters, together with the distance between the FLIR T-660 and the rock face, were used in order to calibrate the thermal imager and correct the apparent temperatures recorded by the device, during the post-processing phase. Successively, vertical profiles showing the temperature of the rock face over time were extracted from the thermograms. Thermal anomalies were correlated with stratigraphic and Geological Strength Index profiles, obtained by means of field surveys and Structure from Motion techniques. The presence of fracture and voids in the rock mass was also investigated.</p>

Sign in / Sign up

Export Citation Format

Share Document