HARBOUR ENGINEERING
Download as PPTX, PDF6 likes2,054 views
The document provides an overview of harbor engineering, detailing the requirements for a good harbor, types of harbors based on protection, utility, and location, as well as critical design aspects such as depth and entrance width. It discusses the impact of meteorological phenomena like wind, tides, and waves on harbor design, and introduces breakwaters as protective structures. Finally, it explains the classification and design of different types of breakwaters, including rubble mound, vertical-wall, and floating breakwaters.
HARBOUR ENGINEERING
- 1. HARBOUR ENGINEERING VISHNU VIJAYAN Assistant Professor& HOD Dept: Civil Engineering BASELIOS MATHEWS II COLLEGE OF ENGINEERING, Kollam,Kerala,INDIA 4/28/2020 1
- 2. HARBOUR: – SHELTERED AREA – FOR LOADING AND UNLOADING OF CARGO – VESSELS ARE ALSO BUILT, REPAIR, AND LAUNCH 4/28/2020 2
- 3. REQUIREMENTS OF A GOOD HARBOR: – THE DEPTH OF A HARBOR SHOULD BE SUFFICIENT FOR EVERY TYPE OF VISITING SHIPS. – THE BOTTOM OF HARBOR SHOULD PROVIDE SECURED ANCHORAGE TO HOLD THE SHIPS AGAINST HIGH WINDS. – TO PREVENT DESTRUCTIVE WAVE ACTION, BREAK WATER ARE PROVIDED. – THE ENTRANCE OF A HARBOR SHOULD BE WIDE ENOUGH TO PROVIDE THE EASY PASSAGE OF SHIPS. 4/28/2020 3
- 4. Classification of Harbor • Depending upon protection needed • Depending upon utility • Depending upon location 4/28/2020 4
- 5. DEPENDING UPON PROTECTION NEEDED 1. NATURAL HARBOUR 2. SEMI NATURAL HARBOUR 3. ARTIFICIAL HARBOUR 4/28/2020 5
- 6. NATURAL HARBOURS: A harbor, is a place where ships, boats, and barges can seek shelter from stormy weather. 4/28/2020 6
- 7. SEMI NATURAL HARBOUR: • Same as natural but harbour needs some artificial and man made construction. 4/28/2020 7
- 8. ARTIFICIAL HARBOUR: • Harbour having no natural protection but artificial arrangement are made to protect the harbour from storm and wind. 4/28/2020 8
- 9. DEPENDING UPON UTILITY OR FUNCTIONAL CLASSIFICATION: • 1. HARBOR OF REFUGE 2. COMMERCIAL HARBOR 3. FISHRY HARBOR 4. MILLITARY HARBOR OR NAVEL BASE 4/28/2020 9
- 10. HARBOR OF REFUGE: • The harbor used for ships in storms or emergency condition. Good anchorage and safe and easy access from the sea. e.g: DOVER IN ENGLAND 4/28/2020 10
- 11. COMMERCIAL HARBOR: Facilities for loading and unloading of cargo are provided. IT MAY BE , 1. Part of bigger complex harbor 2. Independent unit or single commodity harbor. 3. Terminal as oil terminal, coal port. 4/28/2020 11
- 12. 4/28/2020 12
- 13. 4/28/2020 13
- 14. FISHRY HARBOR: Provided for fishing crafts and trawlers. 4/28/2020 14
- 15. MILLITARY HARBOR: This harbor is meant for accommodating naval crafts and serves as a supply deport. The layout of this type of harbor is greatly influenced by its location. 4/28/2020 15
- 16. Classification based on location Layout of harbor greatly influenced by location 1. Canal harbor 2. Lake harbor 3. River harbor 4. Sea harbor 4/28/2020 16
- 17. DRAUGHT • It is a vertical linear immersion of ship below water surface for the ship to float. • Safe floating requires standard vertical clearance between sea bed and bottom of ship. 4/28/2020 17
- 18. 4/28/2020 18
- 19. Size of harbor • Size of harbor depends on number and size of ships likely to use the harbor at one time. • The harbor entrance should be designed and located for quick and easy navigation ships. • It should be narrow enough not expose the harbor to the effect of the stormy area. • Maximum dimension up to 180 M have been adopted. • Modern ships 275 m to 300 m long • 30- 40 m wide. maneuvering4/28/2020 19
- 20. Size determined by • Accommodation required • Convenience for maneuvering and navigation • Adaptability to natural features 4/28/2020 20
- 21. Entrance width • Narrow Entrance will protect the interior portion. • In artificial harbor break water protects the high intensity of waves from sea. • Waves from out side harbor setup diminutive waves inside the harbor depending on the entrance widths. 4/28/2020 21
- 22. Stevens Formula For Entrance width • Empirical formula suggested by Stevenson with a limited application is some times used. • h = 𝑙 𝐿 − 0.027 4 𝐷 (1+ 𝑙 𝐿 )H • H : height of unrestricted wave at the entrance month.(m) • l=width of entrance mouth in M • L= Width of harbor in M • h=reduced ht of diminutive wave inside • This formula applicable to a well protected harbor by a vertical sea wall ,distance of 15 m 4/28/2020 22
- 23. Shape of harbor • principle to follow for deciding shape. • Protect harbor from sea waves , one of the pier head project little beyond others. • Inside the pier heads, the width should widen rapidly. • General shape obtained by a series of straight length and no re-entrants angle should be allowed. 4/28/2020 23
- 24. Harbor Depth • Depth generally determined by the following formula. • D= D1+ 𝐻 3 +D2 • D1= Draft of the largest ship to be accommodated. • D2= allowance for squat of the moving ship. • H = height of storm waves • Maximum harbor depth= loaded draft +1.2 for bottom soft rock. 1.8 for hard rock. 4/28/2020 24
- 25. Site selection 1.Availability of cheap land and construction materials 2. Transport and communication facilities 3. Natural protection from winds and waves 4. Industrial development of the locality 5. Sea-bed subsoil and foundation conditions 6. Traffic potentiality of harbor 7. Availability of electrical energy and fresh water 8. Favorable marine conditions 9. Defense and strategic aspects 4/28/2020 25
- 26. Meteorological phenomenon • Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting. • Focused on ; • Wind • Tides • Wave 4/28/2020 26
- 27. Wind • Wind : Air in motion is known as wind. • Direction and speed should taken from the which the wind blow. • Speed of wind expressed as knots. • 1 knots = 1.852 kmph. 4/28/2020 27
- 28. TIDES • The alternate rising and falling of the sea, usually twice in each lunar day at a particular place, due to the attraction of the moon and sun. 4/28/2020 28
- 29. A lunar day • A lunar day is the period of time it takes for the Earth's Moon to complete one full rotation on its axis with respect to the Sun 4/28/2020 29
- 30. WAVES • The winds cause waves on the surface of the ocean (and on lakes). • The wind transfers some of its energy to the water, through friction between the air molecules and the water molecules. • Stronger winds (like storm surges) cause larger waves. 4/28/2020 30
- 31. HEIGHT AND LENGTH OF WAVES • A crest is the point on a wave with the maximum value or upward displacement within a cycle.. • A trough is the opposite of a crest, so the minimum or lowest point in a cycle. • Fetch, area of ocean or lake surface over which the wind blows in an essentially constant direction, thus generating waves. The term also is used for fetch length (KM), which is the horizontal distance over which wave-generating winds blow. 4/28/2020 31
- 32. • HEIGHT OF THE WAVE IN METERS = 0.34 𝐹 • F Is the fetch in km.(Stevenson formula) 4/28/2020 32
- 33. WAVE ACTION • A sea wave when braking against in a obstacle or marine structure which produce various force. • Air compression • Water harmer 4/28/2020 33
- 34. coastal current • Long shore currents are generated when a "train" of waves reach the coastline and release bursts of energy. • which runs parallel to the shoreline. This type of current is called a “long shore current.” 4/28/2020 34
- 35. Littoral drift Longshore drift is a geographical process that consists of the transportation of sediments (clay, silt, sand and shingle) along a coast at an angle to the shoreline, which is dependent on prevailing wind direction, swash and backwash. This process occurs in the littoral zone, and in or close to the surf zone. The process is also known as littoral drift, longshore current or longshore transport. 4/28/2020 35
- 36. Break water • The protective barrier constructed to enclose harbors and to keep the harbor waters OR The structure constructed to protect harbor from storm waves They are generally stone masonry Through this shelter, to manipulate the littoral/sand transport conditions and thereby to trap some sand entrance inside the Anchorage Area. 4/28/2020 36
- 37. Design of breakwaters: Following information should he collected before the design of a breakwater: 1.Character of coastal currents 2.Cost and availability of materials of construction 3.Directions and force of prevailing winds 4.Nature of the bottom or foundation 5.Probable maximum height, force and intensity of waves. 4/28/2020 37
- 38. Classification of breakwaters: • Breakwaters are classified mainly into three types: A) Rubble Mound Breakwaters B) Vertical-wall breakwaters C) Floating breakwaters 4/28/2020 38
- 39. Rubble Mound Breakwaters It is a heterogeneous assemblage of natural rubble, undressed stone blocks, rip rap, supplemented in many cases by artificial blocks of huge bulk and weight, the whole being deposited without any regard to bond or bedding. 4/28/2020 39
- 40. Rubble Mound Breakwaters • A breakwater constructed by a heterogeneous assemblage of natural rubble or undressed stone. • When water depths are large Rubble Break Water may be uneconomical in view of huge volume of rocks required. • Built up to water depth of 50m. • Not suitable when space is a problem. If the harbor side may have to be used for berthing of ships, the RBW with its sloping faces is not suitable for berthing. • These type of breakwaters dissipate the incident wave energy by forcing them to break on a slope and thus do not produce appreciable reflection.4/28/2020 40
- 41. STRUCTURAL COMPONENT 1) Constructed by natural rubble or undressed stones. 2) Comparatively safe. 3) Has a broad base which helps in distributing the load on a wider area. 4) Consists of central portion called core, protective cover called Armour layer and in between is the under layer. 4/28/2020 41
- 42. 4/28/2020 42
- 43. ADVANTAGES OF RMBW • Use of natural material • Reduces material cost • Use of small construction equipment • Less environmental impact • Most widely used in Indian ports • Easy to construct • Failure is mainly due to poor interlocking capacity between individual blocks • Unavailability of large size natural rocks leads to artificial armour blocks . 4/28/2020 43
- 44. Vertical-wall breakwaters • A breakwater formed by the construction in a regular and systematic manner of a vertical wall of masonry concrete blocks or mass concrete, with vertical and seaward face. • Reflect the incident waves without dissipating much wave energy. • Normally it is constructed in locations where the depth of the sea is greater than twice the design wave height. 4/28/2020 44
- 45. ADVANTAGES OVER RBW • saving in material due to smaller body width. • Rapidity in construction. • Non availability of large quantities of stones. • Occupies less space. 4/28/2020 45
- 46. 4/28/2020 46
- 47. Disadvantages of vertical wall break water • Sea bottom has to be leveled and prepared for placements of large blocks or caissons. • Foundations made of fine sand may cause erosion and settlement. • Erosion may cause tilting or displacement of large monoliths. • Difficult and expensive to repair. • Building of caissons and launching or towing them into position require special land and water areas beside involvement of heavy construction equipment. • Require form work, quality concrete, skilled labour, batching plants and floating crafts. 4/28/2020 47
- 48. FLOATING BREAKWATER • A removable breakwater constructed by caissons or pontoons with valves for trimming whilst afloat and for sinking when is position and pump connections for refloating, moored to the sea bed. • inexpensive, easily moved from site to site, often very quickly fabricated. • ineffective to long waves, must be anchored. 4/28/2020 48
- 49. 4/28/2020 49