Water Length and Height Effects on the Earthquake Behavior of Arch Dam-Reservoir-Foundation Systems

Baris¸ Sevim,Ahmet Can Altuns¸ik,Alemdar Bayraktar,Mehmet Akköse,Yusuf Calayir 대한토목학회 2011 KSCE Journal of Civil Engineering Vol.15 No.2

In this study, water length and height effects on the earthquake behavior of arch dam-reservoir-foundation systems are purposed. The study can be classified into two parts. In the first part, in order to obtain a realistic 3D arch dam-reservoir-foundation model,water length effects on the behavior of the arch dam systems are investigated. For this purpose a double curvature arch dam is modeled by forming four different water lengths related to dam Height (H) as H, 2H, 3H and 4H. Each model is analyzed in time domain and the realistic model is obtained according to the analyses results. In the second part, water height effects on the behavior of the arch dam system are investigated. The arch dam obtained from first part of the study is modeled by forming four different water heights related to dam Height (H) as 0H, 0.33H, 0.66H and H. The behavior of the dam, reservoir and foundation are expressed in terms of displacements using Lagrangian approach. The foundation is taken into account as massless; behavior of reservoir is assumed to be linearly elastic, inviscid and irrotational. In this study, all systems are modeled by ANSYS finite element program and analyses are performed using IMPVALL/I-ELC180 component of Imperial Valley (1940) earthquake. Dynamic equations of motions are solved by using Newmark integration algorithm. It is seen that both water length and height affect the earthquake behavior of the arch dams considerably.

PEG crosslinked poly(vinylbenzene boronic acid) polymer electrolytes for Li-ion batteries

Sevim Ünügür Çelik,Ayhan Bozkurt 한국물리학회 2013 Current Applied Physics Vol.13 No.8

Poly(4-vinylbenzeneboronic acid), PVBBA was synthesized via free-radical polymerization of 4-vinylbenzeneboronic acid (4-VBBA) and followed by crosslinking with polyethylene glycol (PEG) with different molecular weights to produce boron containing crosslinked polymers. Prior to crosslinking, the materials were doped with CF3SO3Li at several stoichiometric ratios to get PVBBAPEGX-Y where X is the molecular weight of PEG and Y is the EO/Li ratio. The materials were characterized by using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC). The ionic conductivity of these novel crosslinked electrolytes was studied by dielectric-impedance spectroscopy. Li-ion conductivity of these polymer electrolytes depends on the length of the side units as well as the doping ratio. PVBBAPEG200-10 illustrated a satisfactory ionic conductivity of 3.1 x 10-5 S/cm at 20 ℃ and 1.8 x 10-3 S/cm at 100 ℃

Structural response of concrete gravity dams under blast loads

Sevim, Baris,Toy, Ahmet Tugrul Techno-Press 2020 Advances in concrete construction Vol.9 No.5

Concrete dams are important structures due to retaining amount of water on their reservoir. So such kind of structures have to be designed against static and dynamic loads. Especially considering on critical importance against blasting threats and environmental safety, dams have to be examined according to the blast loads. This paper aims to investigate structural response of concrete gravity dams under blast loads. For the purpose Sarıyar Concrete Gravity Dam in Turkey is selected for numerical application with its 85 m of reservoir height (H), 255 m of reservoir length (3H), 72 m of bottom and 7 m of top widths. In the study, firstly 3D finite element model of the dam is constituted using ANSYS Workbench software considering dam-reservoir-foundation interaction and a hydrostatic analysis is performed without blast loads. Then, nearly 13 tons TNT explosive are considered 20 m away from downstream of the dam and this is modeled using ANSYS AUTODYN software. After that explicit analyses are performed through 40 milliseconds. Lastly peak pressures obtained from analyses are compared to empirical equations in the literature and UFC 3-340-02 standard which provide unified facilities criteria for structures to resist the effects of accidental explosions. Also analyses' results such as displacements, stresses and strains obtained from both hydrostatic and blasting analysis models are compared to each other. It is highlighted from the study that blasting analysis model has more effective than the only hydrostatic analysis model. So it is highlighted from the study that the design of dams should be included the blast loads.

Geometrical dimensions effects on the seismic response of concrete gravity dams

Sevim, Baris Techno-Press 2018 Advances in concrete construction Vol.6 No.3

This study presents the effects of geometrical dimensions of concrete gravity dams on the seismic response considering different base width/dam height (L/H) ratios. In the study, a concrete gravity dam with the height of 200 m is selected and finite element models of the dam are constituted including five different L/H ratios such as 0.25, 0.5, 0.75, 1.00, 1.25. All dams are modeled in ANSYS software considering dam-reservoir-foundation interaction. 1989 Loma Prieta earthquake records are applied to models in upstream-downstream direction and linear time history analyses are performed. Dynamic equilibrium equations of motions obtained from the finite element models of the coupled systems are solved by using Newmark time integration algorithm. The seismic response of the models is evaluated from analyses presenting natural frequencies, mode shapes, displacements and principal stresses. The results show that the L/H ratios considerably affect the seismic response of gravity dams. Also, the model where L/H ratio is 1.00 has more desirable results and most appropriate representation of the seismic response of gravity dams.

Effects of the vertical component of ground motion on the seismic performance of Bhakra Gravity Dam

Sevim, Baris,Altunisik, Ahmet Can,Gunaydin, Murat Techno-Press 2021 Advances in concrete construction Vol.12 No.3

In this paper, the earthquake component effects on the seismic performance of Bhakra Gravity Dam in India are investigated. For the purpose, Bhakra Dam is modeled two-dimensionally considering dam-reservoir-foundation interaction. In the finite element modeling, dam and foundation are represented by PLANE182 elements in ANSYS with different material properties, and fluid is considered with FLUID29 elements. This type of element provides translation and pressure degrees of freedom. Linear time history analyses on the dam are performed by considering components of the 1991 Uttarkashi and 1999 Chamoli (NW Himalaya) Earthquakes in India. During the analyses firstly the horizontal component of earthquakes are applied to system and results are obtained, and then both of horizontal and vertical components are applied to the systems together. In the analyses, element matrices are computed using the Gauss numerical integration technique. The Newmark method is used in the solution of the equation of motions. Also, Rayleigh damping is considered. The seismic performance of Bhakra Dam is examined and presented by dynamic characteristics, displacements, principal stresses, and demand-capacity ratios. The results showed that the vertical components of the earthquake significantly affect the response of the dam. The results show that the vertical component with the horizontal component cause biggest tensile stresses compared to only the horizontal component for both earthquakes. However, displacement response is changed depending on the ground motion. As a conclusion of this study it can be said that the vertical component changes the structural response of the dam on both of the good and bad behaviors.

A Novel cry2Ab Gene from the Indigenous Isolate Bacillus thuringiensis subsp. kurstaki

( Sevim Ali ),( Emine Eryuzlu1 ),( Zihni Demirba ),( Smail Demir ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.1

A novel cry2Ab gene was cloned and sequenced from the indigenous isolate of Bacillus thuringiensis subsp. kurstaki. This gene was designated as cry2Ab25 and its sequence revealed an open reading frame of 1,902 bp encoding a 633 aa protein with calculated molecular mass of 70 kDa and pI value of 8.98. The amino acid sequence of the Cry2Ab25 protein was compared with previously known Cry2Ab toxins, and the phylogenetic relationships among them were determined. The deduced amino acid sequence of the Cry2Ab25 protein showed 99% homology to the known Cry2Ab proteins, except for Cry2Ab10 and Cry2Ab12 with 97% homology, and a variation in one amino acid residue in comparison with all known Cry2Ab proteins. The cry2Ab25 gene was expressed in Escherichia coli BL21(DE3) cells. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that the Cry2Ab25 protein is about 70 kDa. The toxin expressed in BL21(DE3) exhibited high toxicity against Malacosoma neustria and Rhagoletis cerasi with 73% and 75% mortality after 5 days of treatment, respectively.

Structural identification of concrete arch dams by ambient vibration tests

Sevim, Baris,Altunisik, Ahmet Can,Bayraktar, Alemdar Techno-Press 2013 Advances in concrete construction Vol.1 No.3

Modal testing, widely accepted and applied method for determining the dynamic characteristics of structures for operational conditions, uses known or unknown vibrations in structures. The method's common applications includes estimation of dynamic characteristics and also damage detection and monitoring of structural performance. In this study, the structural identification of concrete arch dams is determined using ambient vibration tests which is one of the modal testing methods. For the purpose, several ambient vibration tests are conducted to an arch dam. Sensitive accelerometers were placed on the different points of the crest and a gallery of the dam, and signals are collected for the process. Enhanced Frequency Domain Decomposition technique is used for the extraction of natural frequencies, mode shapes and damping ratios. A total of eight natural frequencies are attained by experimentally for each test setup, which ranges between 0-12 Hz. The results obtained from each ambient vibration tests are presented and compared with each other in detail. There is a good agreement between the results for all measurements. However, the theoretical fundamental frequency of Berke Arch Dam is a little different from the experimental.

Investigation of water length effects on the modal behavior of a prototype arch dam using operational and analytical modal analyses

Sevim, Baris,Bayraktar, Alemdar,Altunisik, Ahmet Can Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.6

This study determines the water length effects on the modal behavior of a prototype arch dam using Operational and Analytical Modal Analyses. Achievement of this purpose involves construction of a prototype arch dam-reservoir-foundation model under laboratory conditions. In the model, reservoir length was taken to be as much as three times the dam height. To determine the experimental dynamic characteristics of the arch dam using Operational Modal Analysis, ambient vibration tests were implemented for empty reservoir and three different reservoir water lengths. In the ambient vibration tests, the dam was vibrated by natural excitations provided from small impact effects and the response signals were measured using sensitive accelerometers. Operational Modal Analysis software process signals collected from the ambient vibration tests, and Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification techniques estimated modal parameters of the dams. To validate the experimental results, 3D finite element model of the prototype arch dam was modeled by ANSYS software for empty reservoir and three different reservoir water lengths, and dynamic characteristics of each model were determined analytically. At the end of the study, experimentally and analytically identified dynamic characteristics compared to each other. Also, changes on the natural frequencies along to water length are plotted as graphs. Results suggest that reservoir water complicates the modal behavior of the arch dam significantly.

Investigation of water length effects on the modal behavior of a prototype arch dam using operational and analytical modal analyses

Baris Sevim,Alemdar Bayraktar,Ahmet Can Altunisik 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.37 No.6

This study determines the water length effects on the modal behavior of a prototype arch dam using Operational and Analytical Modal Analyses. Achievement of this purpose involves construction of a prototype arch dam-reservoir-foundation model under laboratory conditions. In the model, reservoir length was taken to be as much as three times the dam height. To determine the experimental dynamic characteristics of the arch dam using Operational Modal Analysis, ambient vibration tests were implemented for empty reservoir and three different reservoir water lengths. In the ambient vibration tests,the dam was vibrated by natural excitations provided from small impact effects and the response signals were measured using sensitive accelerometers. Operational Modal Analysis software process signals collected from the ambient vibration tests, and Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification techniques estimated modal parameters of the dams. To validate the experimental results, 3D finite element model of the prototype arch dam was modeled by ANSYS software for empty reservoir and three different reservoir water lengths, and dynamic characteristics of each model were determined analytically. At the end of the study, experimentally and analytically identified dynamic characteristics compared to each other. Also, changes on the natural frequencies along to water length are plotted as graphs. Results suggest that reservoir water complicates the modal behavior of the arch dam significantly.

Modified pectoral nerve block versus bi-level erector spinae plane block for postoperative analgesia after radical mastectomy surgery: a prospective, randomized, controlled trial

Cesur Sevim,Aksu Can,Güler Sertaç Ata,Kuş Alparslan 대한마취통증의학회 2023 Korean Journal of Anesthesiology Vol.76 No.4

Background: Regional anesthesia techniques constitute an important part of successful analgesia strategies in the perioperative care of patients undergoing breast surgery. The advent of ultrasound-guided regional anesthesia has led to the development of fascial plane blocks. The large array of blocks available for postoperative analgesia in breast surgery has increased the accessibility of regional anesthesia but has also created a dilemma of choice. This study compared the analgesic efficacy of the ultrasound-guided modified pectoral nerve (PECS) block and erector spinae plane block (ESPB) in patients undergoing radical mastectomy.Methods: Seventy women were enrolled in this prospective, double-blind, randomized control trial. After exclusion, 67 female patients who underwent radical mastectomy were finally analyzed. Ultrasound-guided PECS blocks and ESPBs were performed with 30 ml 0.25% bupivacaine. Postoperative morphine and pain scores were compared between the groups.Results: Postoperative total morphine consumption in the first 24 h was significantly higher in the PECS group (P < 0.001). The ESPB group exhibited significantly reduced morphine consumption at all postoperative time points. Numeric rating scale scores were lower in the ESPB group at 6, 12, and 24 h postoperatively at rest and when coughing.Conclusions: Ultrasound-guided bi-level ESPBs provided better postoperative analgesia than PECS blocks after radical mastectomy surgery.