Design Examples and Exercises for Hydraulic Structures

Author: Chief Editor: Yang Shukuan
Publisher:
Publishing Date: 2005-07-01
Features: Synopsis This book is divided into two parts: Part I Thinking Questions and Exercises (including Introduction, Gravity Dams, Arch Dams, Earth-Rock Dams, Sluice Gates, Riverbank Spillways, Hydraulic Tunnels and Culverts, Canals and Canal System Structures, and Layout of Hydraulic Structures); Part II Design Examples, which specifically and systematically introduce the design steps and methods for gravity dam structures on rock foundations, arch dam structures, earth-rock dam structures, sluice gate structures, and rib-arch aqueducts. This book is primarily intended as a supplementary reading for the "Hydraulic Structures" course in secondary vocational schools and can also be used as a reference for engineering technicians engaged in the planning, design, and construction of small and medium-sized hydraulic structures. Excerpt: Chapter Gravity Dams on Rock Foundations
I. Thinking Questions
1. What are the working characteristics of gravity dams?
2. What are the main loads acting on gravity dams, and how are they calculated?
3. What is the effect of uplift pressure on gravity dams? What measures can be taken to reduce uplift pressure?
4. Why are load combinations necessary?
5. What are the differences between the shear strength formula and the shear resistance formula in sliding stability calculations? What engineering measures can enhance the sliding stability of the dam body?
6. What is the purpose of stress analysis for gravity dams? What are the stress control indicators and calculation formulas?
7. How can the basic profile shape and dimensions of the water-retaining dam be determined? What are the main basis for this determination?
8. How can the profile of an overflow dam be designed? What energy dissipation types are commonly used, and what are their applicable conditions?
9. What are the various methods of water discharge for overflow dams, and what are their characteristics?
10. What are the components of a deep water discharge tunnel, and what design considerations should be noted for each component?
11. Why are gravity dams divided into sections?
12. What is the purpose of setting galleries in gravity dams, and what should be noted during their layout?
13. What are the requirements for the foundation of gravity dams?
14. What are the methods for waterproofing the body of a masonry gravity dam?
15. What are the characteristics of other types of gravity dams, and what are their applicable conditions?
II. Exercises
1. As shown in Figure 11-1, calculate the uplift pressure at the dam base under both conditions with and without drainage holes.
2. A concrete gravity dam in a mountainous area is classified as a Class IV structure. The riverbed section of the water-retaining dam is shown in Figure 1-1-2.
(1) Basic Data:
1) Average wind speed υ = 16 m/s, fetch D = 1.5 km.
2) Design flood level = 229.0 m, normal water level = 227.0 m, silt level = 204.0 m, and silt buoyancy weight γm = 7 kN/m3, internal friction angle φ = 18°.
3) Concrete unit weight γc = 24 kN/m3.
4) Foundation rock f = 1.0, cohesion c = 0.9 MPa.
(2) Calculation Requirements:
1) Determine the dam crest elevation (if a parapet is set, calculate both the dam crest and parapet crest elevations).
2) Calculate all loads acting on the gravity dam (see Table 1-1-1).
3) Verify the sliding stability along the dam foundation under the normal water level.