Numerical modelling of reinforced concrete pressure tunnels using the overlapping lattice method

Download

index.pdf

Date

2019

Author

Işık, Gökberk

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

312
views

138
downloads

Pressure tunnels transmit water from the reservoir to the turbines of hydroelectric power plants. The computational studies conducted to understand the behavior and shed light on the design guides of pressure tunnels were scarcely validated with experimental data as experimental work on pressure tunnels is very limited. Recent experimental studies on reinforced concrete pressure tunnels carried out at Middle East Technical University (METU), for the first time, allow computational models to be validated with experimental data. Instead of the conventional approach of using finite elements with smeared and discrete crack models, in this study, an Overlapping Lattice Model (OLM) was used to simulate the nonlinear behavior of the reinforced concrete tunnel as well as the surrounding rock body. First, parameters used in the OLM were calibrated using the fracture energy, the tensile strength and the elasticity modulus of concrete. A normalization rule was developed to make sure that energy dissipation is independent of lattice length scale. Then, the quasi-static tunnel experiments performed at METU were simulated and internal pressure-tunnel expansion curves as well as crack patterns obtained in the numerical studies were compared with the experimental observations. OLM predictions are shown to be in agreement with the experimental data. Calibrated model was then applied to study dynamic crack initiation and propagation in pressure tunnels. In line with the experimental observations and numerical inferences, in-situ stress conditions in the surrounding rock body play an important role on the behavior of the tunnel lining. Low confining stress or lack of sufficient contact between tunnel lining and surrounding rock body are possible causes of the cracks observed in pressure tunnels. As a future research opportunity, OLM developed in the context of this research can be used to evaluate the seismic behavior of tunnels.

Subject Keywords

Tunnels., Pressure Tunnel, Reinforced Concrete, Simulation, Lattice Model, Fracture Mechanics.

URI

http://etd.lib.metu.edu.tr/upload/12624318/index.pdf
https://hdl.handle.net/11511/46108

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Numerical reservoir simulation of Alaşehir geothermal field Aydın, Hakkı; Akın, Serhat (null; 2020-02-10) Use of a comprehensive reservoir simulation is essential for an effective geothermal reservoir management. TOUGH2 has become a widely used simulator for this purpose. In this study, one of the most exploited geothermal fields in Turkey, Alaşehir geothermal field has been modeled by using TOUGH2 reservoir simulator. The study includes more than 100 wells, which are operated by 7 different developers. The total installed capacity of geothermal power plants in the field is 212 MWe, but additional capacity (98 ...
Seismic Performance Evaluation of Concrete Gravity Dams by Using Pseudo Dynamic Testing and Simulations Aldemir, Alper; Binici, Barış (null; 2017-11-24) Dams are one of the mostimportantinfrastructure components servingfor water storage and energyproduction.Experimental studies on the seismic response of concrete gravity dams are scarce due to the complications regarding thelargescaleof dams and their interaction with the reservoir. This study presents the results of recent novel pseudo-dynamic dam tests (PSD) along with the nonlinear finite element simulations of the specimens. The test specimens were 1/75 scaled version of the highest ...
Computer Assisted Preliminary Design of Run-Of-River Plants Alimoglu, Emir; Bozkuş, Zafer; Yanmaz, A. Melih (2014-10-01) Run-of-river type hydroelectric power plants generate electrical energy by using a certain portion of the available flow in the river. In this study a computer program called MINI-HPD is developed to perform the hydraulic design of run-of-river plants. This program, which runs under the Windows operating system, is developed in C# programming language. MINI-HPD is capable of performing hydraulic design of structural components of diversion weir with lateral intake, overflow spillway, canal, forebay and pens...
Design of settling basins and related problems encountered in practice Zaloğlu, Fatma Deniz; Göğüş, Mustafa; Department of Civil Engineering (2013) Settling basins are the hydraulic structures used to get sediment-free water from rivers mostly for hydropower systems. Mainly fine sediment is trapped along the settling basins and from time to time the accumulated sediment in the settling basin is flushed away. A wrong design of a settling basin creates lots of problems. In this study based on the hydraulic analysis of a settling basin, the available settling basin design procedures in the literature were reviewed. Some of the settling basins constructed ...
Analysis Methods for the Investigation of the Seismic Response of Concrete Dams Aldemir, Alper; Yilmazturk, Sema Melek; Yucel, Ali Riza; Binici, Barış; Arıcı, Yalın; Akman, Altug (2015-01-01) The consideratiOn of the dam-foundation-reservoir interaction is extremely important for estimating the seismic response of concrete gravity dams. Moreover, nonlinear analysis may be required for determining the possible risk associated with dams. In order to address these issues, DSI recently published the "Guidelines for Seismic Design of Concrete Dams". Authors who have contributed to the preparation of this document provide a perspective on the seismic safety/design of concrete dams and structural analy...

Citation Formats

G. Işık, “Numerical modelling of reinforced concrete pressure tunnels using the overlapping lattice method,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences . Earthquake Studies., Middle East Technical University, 2019.