Geri Dön

Türkiye barajlarında dolusavak kapasitelerinin incelenmesi

Examination of dams's spillway capacity in Turkey

  1. Tez No: 75596
  2. Yazar: MEHMET ÇAĞLAR KOÇ
  3. Danışmanlar: PROF. DR. CEVAT ERKEK
  4. Tez Türü: Yüksek Lisans
  5. Konular: İnşaat Mühendisliği, Civil Engineering
  6. Anahtar Kelimeler: Belirtilmemiş.
  7. Yıl: 1998
  8. Dil: Türkçe
  9. Üniversite: İstanbul Teknik Üniversitesi
  10. Enstitü: Fen Bilimleri Enstitüsü
  11. Ana Bilim Dalı: İnşaat Mühendisliği Ana Bilim Dalı
  12. Bilim Dalı: Su Mühendisliği Bilim Dalı
  13. Sayfa Sayısı: 145

Özet

ÖZET Nüfusun çoğalması, sanayinin gelişmesi suya olan gereksiminin artmasına yol açmıştır. Su kaynaklarının, bu gereksinimleri karşılayabilmesi için insanlar değişik çalışmalara yönelmiştir. Bu çalışmaların en önemlilerinden biri de baraj inşaatıdır. Türkiye gibi akarsu rejimleri düzensiz ülkelerde yaz aylarında akarsu debilerinin azalması ve kış sonlarında taşkınlara varabilecek boyutlarda artması su kaynaklarından yararlanmayı minimum seviyeye indirmektedir. Baraj yapımı burada büyük önem kazanır. Barajların emniyet yönünden en önemli yapısı dolusavaklardır. Dolusavaklar, taşkın esnasında gelen fazla suları baraj üzerinden veya baraj gövdesinden bağımsız olarak göl yamacından mansaba akıtmak için açık kanal veya kapalı mecra şeklinde planlanan deşarj yapılarıdır. Bu tez çalışması sırasında, dolusavaklarla ilgili genel bilgiler verilmiştir. Bu bilgiler ışığında dolusavakların hesabında kullanılan yöntemlerden ve dolusavakların sınıflandırılmasından bahsedilmiştir. Tezin asıl çalışma alanı olan Türkiye'deki dolusavakların özellikleri ve bu özelliklerden yararlanarak bundan sonraki dolusavak yapımında bir kriter oluşturabileceği düşünülmüştür. Çalışmanın 1. Bölümünde konunun önemi ve çalışmanın amacı hakkında bilgi verilmiştir. 2. Bölümde dolusavakların genel özellikleri incelenmiştir. Önce dolusavakların kısımlan ele alınmış ve bunların hakkında açıklamalar yapılmıştır. Daha sonra dolusavaklar sınıflandırılarak tip seçimini etkileyen başlıca faktörler ele alınmıştır. Bu bölümün sonunda dolusavakların tipleri hakkında genel bilgiler verilmiştir. 3. Bölümde dolusavakların projelendirilme esasları incelenmiştir. Burada dolusavakların projelendirilmesi için gerekli doneler, serbest akımlı savakların hidrolik hesabı, kapaklı savakların hidrolik hesabı ve dolusavakların mansabında yer alan akımların hidroliği anlatılmıştır. 4. Bölümde ise Türkiye'deki barajların dolusavak özellikleri tablolar ve bu tablolardan elde edilen grafiklere yer verilmiş ve bunlardan çıkan sonuçlar hakkında orumlar yapılmıştır. XII

Özet (Çeviri)

SUMMARY EXAMINATION OF DAMS'S SPILLWAY CAPASITY IN TURKEY In this thesis, some general knowledge about spillways has been given and depending this knowledge, has been explained some basic equations and formulas that are used to calculate spillway design. Main subject in this thesis is, examination of dams' s spillway capasity in Turkey and determine some criterion about spillways which will have been built in the future. For this aim, a lot of knowledges have been collected and then this hydraulic structures features have been examined in detail. Some statistics and historical informations have been given below. The first dam built in Turkey during the Republic era is the Çubuk I dam, built for the domestic water requirement of the city of Ankara. No serious activities in dam construction was observed until the end of Second World War except few low dams built for irrigation purposes. Since then however, an increase in construction of dams and hydroelectric power plants can be observed. Annual rainfall in Turkey varies between 220 mm to 2500 mm with an average of 642.6 mm. This corresponds to an average annual rainfall of 501 knr\ Approximately 186 km“' of this amount flows as surface water. Studies made by D.S.İ. indicate that with the construction of 702 dams and 494 hydroelectric power plants (including the ones under construction, planning and in operation) it will be possible to regulate Turkey rivers and make maximum use of them. As the beginning of July 1997, construction of 178 dams have been completed and put into operation. xiiiIn case the above dams and hydroelectric power plants are completed, it will be possible to produce yearly 124. 1 TWh of energy with an installed capacity of 35132 MW and besides, great benefits will be obtained from irrigation, flood control and domestic and industrial use of water. The purpose of the spillway is to pass flood water safely down stream when the reservoir is full. It has five principal components; the inlet structure, the controlling spillweir, the conduit structure, the energy breaker and the outlet structure. Dam's Lake Coutrolng SpiSwar Conetai Structure Energy Breaker Outlet Structure Figure 1 Typical Side Channel and Spillway Arrangement XIVSpillways are provided for storage and detention dams to release surplus water or floodwater that cannot be contained in the allotted storage space, and for diversion dams to bypass flows exceeding those turned into the diversion system. Ordinarily, the excess is drawn from the top of the reservoir and conveyed through a constructed waterway back to the river or to some natural drainage channel. Figure 3 shows a typical straight drop spillway installation for small heads. r- 2) Controlling Spillweir 4)Energy dissipator 5)Outlet Structure Figure 2 Cross Section of Concrete Dam Spillway The importance of a safe spillway cannot be overemphasized; many failures of dams have been caused by improperly designed spillways or by spillways of insufficient capacity. Ample capacity is of paramount importance for earthfill and rockfill dams, which are likely to be destroyed if overtopped; whereas, concrete dams may be able to withstand moderate overtopping. Usually, the increase in cost is not directly proportional to the increase in capacity. The cost of a spillway having ample capacity is often only moderately higher than the cost of a spillway that is too small. xvIn addition to providing sufficient capasity, the spillway must be hydraulically and structurally adequate and must be located so that spillway discharges do not erode or undermine the downstream toe of the dam. The spillway's bounding surfaces must be erosion resistant to withstand the high scouring velocities created by the drop from the reservoir surface to the tailwater level. Usually, a device is required to dissipate the energy of the water at the bottom of the drop. Classification of Spillways a) Overfall Spillways The basic shape of the overfall (ogee) spillway is derived from the lower envelope of the overall nappe flowing over a high vertical rectangular notch with an approach velocity Vo«0 and a full aerated space beneath the nappe. Q =C. L.H3/2 (1) Q : Discharge C : Spillway coefficient H : Spillway head L : Spillway length For an overflow spillway we can thus write equation (1) b) Side-Channel Spillways Side-channel spillways are mainly used when it is not possible or advisable to use a direct overfall spillway as, at earth and rockfill dams. They are placed on the side of the dam and have a spillway proper, the flume (channel) downstream of the spillway, followed by a chute or tunnel. Sometimes a spillway that is curved in plan is used, but most frequently it is straight and more or less perpendicular to the dam axis, the latter is certainly the case in a gated spillway. xvic) Chute Spillway A chute spillway is a steep channel conveying the discharge from a low- overfall, side-channel, or special shape spillway over the valley side into the river down stream. The design of chute spillways requires the handling of three problems associated with supercritical flow: waves of interference, translatory waves, and self- aeration. d) Shaft Spillways A shaft spillway consists of a funnel-shaped spillway, usually circular in plan, a vertical shaft, a bend, and a tunnel terminating in an outflow. Shaft spillway can also be combined with a draw-off tower; the tunnel may also be used as part of the bottom outlets or even a turbine tailface. For the free overfall the discharge is given by: Q=2/3.Cd. %.Dc.(2g)1/2.H3/2 (2) Cd : Coefficient of discharge Dc : Inlet structure diameter g : Gravitational acceleration e) Siphon Spillways Siphon spillways are closed conduits in the form of an inverted U with an inlet, short upper leg, throat (control section), lower leg, and outlet. For very low flows a siphon spillway operates as a weir; as the flow increases, the upstream water level rises, the velocity in the siphon insreases, and the flow in the lower leg begins to exhaust air from the top of the siphon until this primes and begins to flow full as a pipe, with the discharge given by: Q=Cd.A.(2.g.H)1/2 (3) xviiwhere A is the (throat) cross section of the siphon, H is the difference between the upstream water level and siphon outlet or downstream water level if the outlet is submerged, and Cd=l/(k1+k2+k3+k4)1/”(4) where ki,k2,k3 and İC4 are head loss coefficients for the entry, bend, exit and friction losses in the siphon. In part 4 constructed dams spillway have been examined. Some criterias have been taken out for projection spillways which can be build in the future. To do these comments, characteristics of spillways in Turkey must be known. These datas have been collected from D.S.İ. (Devlet Su İşleri) General Management's archives in Ankara. At the end of the these studies 3 tables have been prepared. These tables are given as below, 1) Characteristics datas of constructed dams in Turkey, 2) Characteristics datas of constructed dams's spillway in Turkey, 3) Spillways types of constructed dams in Turkey. In Figure 4.1 the connection between spillway design flood discharge and spillway head of constructed dams in Turkey is given. According to this, the equation of line, shows the average values of datas, is given as below, h = 0,118.(Qp)0'515 (5) equation can be written. In this equation h is spillway head (m), Qp is spillway design flood discharge. When spillway design discharge is increasing, the spillway head is also increasing. xviiiIn Figure 4.2 the connection between spillway head and volume of rezervuar of constructed dams in Turkey is given. According to this, the equation of line, shows the average values of datas, is given as below, h = 0,95. V0'35 (6) equation can be written. In this equation h is spillway head (m), V is volume of rezervuar (hm3). In Figure 4.3 the change between spillway coefficient and spillway head is examined. From this figure the spillway coefficient lower limit is 1,8. The smallest value of spillway discharge coefficient u=l. 8/2.953=0.61 can be taken. In Figure 4.4 the change between spillway coefficient and spillway head is examined. From this examination, spillway coefficient is changing between 1.4 and 1.8. 1.65 can be given for an average value. In Figure 4.5 the connection between design discharge and water basin pooling area is shown. Topographic, meteorological and hydrologic situations show very big differences in Turkey stream basins. Because of this, marked values scatter very large field as expected. With all these situations an average value, Qp=18.A0'67 (7) can be given. In this equation Qp is design flood discharge (m7s) and A is dam water basin pooling area (km2). In Figures 4.6 up to 4.41 show the biggest historical and the 100 year biggest floods in stream basin of spillway flood discharge. Most of the design flood discharges of dams are smaller than the biggest floods but bigger than the 100 year biggest floods can be easily seen in these figures. xix

Benzer Tezler

  1. Tez No

    424171

    Dolusavak ve enerji kırıcı yapı tip seçiminin uzman sistemler ile belirlenmesi

    Type selection of spillway and energy dissipator structure using expert systems

    ENES GÜL

    Yüksek Lisans

    Türkçe

    Türkçe

    2015

    İnşaat MühendisliğiFırat Üniversitesi

    İnşaat Mühendisliği Ana Bilim Dalı

    PROF. DR. MUHAMMET EMİN EMİROĞLU

  2. Tez No

    151188

    Basamaklı doluksavaklar boyunca oluşan akımların teorik ve deneysel araştırılması

    Theoretical and experimental analysis of flows over stepped spillways

    GÖKÇEN EBEN BOMBAR

    Yüksek Lisans

    Türkçe

    Türkçe

    2004

    İnşaat MühendisliğiDokuz Eylül Üniversitesi

    Hidrolik Hidroloji ve Su Kaynakları Ana Bilim Dalı

    PROF. DR. ŞÜKRÜ GÜNEY

  3. Tez No

    101066

    Baraj dolusavakları tasarımı

    Design of dam spillways

    M. SAVAŞ SANCAR

    Yüksek Lisans

    Türkçe

    Türkçe

    2000

    İnşaat Mühendisliğiİstanbul Teknik Üniversitesi

    PROF.DR. EMİN SAVCI

  4. Tez No

    563206

    Yukarı Fırat havzasındaki mevsimsel kar erimesinin WRF-ARW simülasyonu ve uydu verileri kullanılarak incelenmesi : Mart 2004 örneği

    Investigation of seasonal snow melting by using WRF-ARW simulation and satellite data in the Upper Fırat basin: March 2004 case

    ELİS GÜLER

    Yüksek Lisans

    Türkçe

    Türkçe

    2019

    Meteorolojiİstanbul Teknik Üniversitesi

    Meteoroloji Mühendisliği Ana Bilim Dalı

    DOÇ. DR. BARIŞ ÖNOL

  5. Tez No

    609556

    Atatürk baraj bendinin yıkılmasıyla oluşacak taşkın ve etkilerinin CBS yardımıyla incelenmesi

    Investigation of the flows and effects as a result of Atatür dam break with the help of GIS

    TUĞBA ŞEN

    Yüksek Lisans

    Türkçe

    Türkçe

    2019

    Jeodezi ve Fotogrametriİstanbul Teknik Üniversitesi

    Geomatik Mühendisliği Ana Bilim Dalı

    DOÇ. DR. HİMMET KARAMAN

Geri Dön