Conventional tunneling excavation 10 meters below existing river using 25-meter long forepoling and controlled blasting method, Pahang-Selangor Raw Water Transfer Tunnel Project, Malaysia

2013 ◽  
pp. 2316-2323
Author(s):  
T Kawata ◽  
Y Nakano ◽  
Y Honda ◽  
S Isoda
Keyword(s):  
Water Transfer ◽  
Raw Water ◽  
Blasting Method

Rock Overstressing in Deep Tunnel Excavation of Pahang-Selangor Raw Water Transfer Project

2015 ◽  
Vol 802 ◽  
pp. 16-21 ◽  
Author(s):  
Romziah Azit ◽  
Mohd Ashraf Mohamad Ismail ◽  
Sharifah Farah Fariza Syed Zainal ◽  
Norzani Mahmood
Keyword(s):  
Rock Strength ◽  
Stress Measurement ◽  
In Situ Stress ◽  
Water Transfer ◽  
Stress Factors ◽  
Raw Water ◽  
Tunnel Excavation ◽  
In Situ Stress Measurement ◽  
Assessment Approach

Tunneling under high overburden and in-situ stress may cause tunnel instability because of rock overstressing. Evaluating overstressing in deep hard rocks is crucial to minimize excavation risks. The excavation of the Pahang-Selangor Raw Water Transfer Tunnel is evaluated in this study. A potential overstressing problem is expected at a tunnel depth more than 500 m. Therefore, the possibility of rock overstressing is assessed based on the evaluations of in-situ stress measurement, rock strength, and actual observations during the tunnel excavation. An analytical method is used to analyze the behavior of the tunnel under high overburden stress based on rock strength and tangential stress factors. The empirical assessment approach to the observation of actual overstressing appeared to be valid for the prediction of overstressing. These approaches facilitate the reasonable prediction of tunnel behavior under different rock conditions, support systems, and overburden stresses, which serve as useful tools in the observational design and construction method of long and deep tunnels.

Groundwater Inflows Characterization in the Pahang-Selangor Raw Water Transfer Tunnel Using δ2H and δ18O as Tracers

2015 ◽  
Vol 802 ◽  
pp. 22-27
Author(s):  
Sharifah Farah Fariza Syed Zainal ◽  
Mohd Ashraf Mohamad Ismail ◽  
Roslanzairi Mostafa ◽  
Romziah Azit
Keyword(s):  
Stable Isotope ◽  
Meteoric Water ◽  
Hot Spring ◽  
Water Transfer ◽  
Flow Path ◽  
Water Infiltration ◽  
Seepage Water ◽  
Mountainous Region ◽  
Raw Water ◽  
Altitude Effect

Groundwater inflows represent a very important element in hydrological circulation. Water inflows in Pahang-Selangor Raw Water Transfer Tunnel have been analyzed for isotopes stable of δ2H and δ18O. 61 samples were collected, including Tunnel Seepage Water (TSW), surface water and hot spring water samples within the study area which to understand the effect of multi topographical scale and geological characteristic. Deuterium (δ2H) and Oxygen-18 (δ18O) contributes the understanding of the origin and flow paths of water in the mountainous region. The δ2H and δ18O data obtained from TSW samples ranging from-45.73%0to-54.68%0and-46.01%0to-58.49%0are clustered along the local meteoric water line (LMWL) indicating that the groundwater originated from meteoric water. δ2H and δ18O data, primarily indicate the recharge altitude from 100m–550m which control by the sub vertical flow path mainly from geological structures (i.e. fractures and faults) followed by the groundwater. The altitude effect is indicated by the relation between the stable isotope values and elevation in meters highlighting a depletion of the heavy stable isotope with the increase of the tunnel overburden. The general trend obtained is δ2H and δ18O decreased with the increase of the overburden. The deviation of the δ2H and δ18O data from the expected trends may reflect the recharges are coming from the sub-horizontal flow path such as rivers or water infiltration from the valley. The results show that environmental isotopes indicates a better understanding of the complex hydrogeological system in a mountainous region and interaction between groundwater in granitic and meta-sedimentary rock formation along the tunnel project.

IN-SITU STRESS MEASUREMENT BY OVERCORING AND HYDRAULIC FRACTURING OF PAHANG-SELANGOR RAW WATER TRANSFER PROJECT

2016 ◽  
Vol 78 (8-6) ◽  
Author(s):  
Romziah Azit ◽  
Mohd Ashraf Mohamad Ismail ◽  
Norzani Mahmood
Keyword(s):  
Hydraulic Fracturing ◽  
Stress Measurement ◽  
Vertical Direction ◽  
In Situ Stress ◽  
Peninsular Malaysia ◽  
Water Transfer ◽  
Vertical Stress ◽  
Raw Water ◽  
In Situ Stress Measurement

Estimation of in-situ stress orientation and magnitude is necessary for assessing the excavation risks for Pahang-Selangor Raw Water Transfer (PSRWT) tunnel project. However, the in-situ stress state of the rock generally differs according to area and depth. Therefore, the in-situ stress measurements test in the tunnel are determined in three (3) locations, which are at Adit 2, TBM 2, and Adit 3, in which the overburdens are 227, 1130, and 570 m, respectively. The stress relief method of overcoring technique and hydraulic fracturing by high stiffness system were applied for this project. The results demonstrate that the existence of high vertical stress was estimated in particular in the TBM 2. The maximum principal stress is determined nearly along the vertical direction. Meanwhile, the stress in the horizontal plane is relatively small, and the horizontal to vertical stress ratio is less than one (1). The direction of the horizontal stress obtained is N8E, N14W, and N41E. Results indicate that this method is suitable for estimating in-situ stresses in deep tunnels. The above data and their interpretations enhance the stress database for Peninsular Malaysia

scholarly journals Effects of culvert length and flow rates of raw water transport on biofilm development and water quality

2021 ◽  
Author(s):  
Ruikang Xue ◽  
Tinglin Huang ◽  
Gang Wen ◽  
Junle Yan ◽  
Qian Liu
Keyword(s):  
Water Quality ◽  
Water Transport ◽  
Cell Number ◽  
Water Transfer ◽  
Plate Count ◽  
Raw Water ◽  
Long Distance ◽  
Biofilm Growth ◽  
Flow Rates ◽  
Biofilm Development

Abstract Long-distance water transfer projects are important for water allocation. To enhance our understanding of biofilm growth and changes in water quality during raw water transfer, raw water through long-distance non-full culvert at flow rates of 1.4−2.0 m/s was studied.The results revealed that: (1) the biofilm total cell number (TCC) and heterotrophic plate count (HPC) were the highest at a flow rate of 1.5 m/s, which were 3.7E + 04 cells /cm2 and 1.1E + 03 CFU/cm2, respectively; (2) proteobacteria had the highest relative abundance (RA) among all samples, and the RA in biofilm (78.85%) was higher than that in water (48%−59%); (3) when the pollutants and biofilm were partially shed, the total phosphorus (TP), permanganate index (CODMn), and dissolved organic carbon (DOC) increased by 0.011, 0.36, and 0.5 mg/L at most, respectively; and (4) dissolved oxygen (DO) was sufficient during non-full flow water transport and nitrification occurred. The highest removal rates of ammonium nitrogen (NH+4-N) and nitrous nitrogen (NO2--N) reached 27.16% and 66.76%, respectively. At the flow rates of 2.0 m/s, the efficiency decreased to 10.47% and 41.25%, respectively, due to the shedding of biofilm.

Hydrogeochemistry of tunnel seepage water along the contact of zone of metasedimentary and granitic rock within the Pahang–Selangor Raw Water Transfer Tunnel Project, Malaysia

2016 ◽  
Vol 9 (4) ◽  
Author(s):  
Sharifah Farah Fariza Syed Zainal ◽  
Mohd Ashraf Mohamad Ismail ◽  
Roslanzairi Mostafa ◽  
Nobuya Narita ◽  
Norzani Mahmood ◽  
...  
Keyword(s):  
Granitic Rock ◽  
Water Transfer ◽  
Seepage Water ◽  
Raw Water
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