Source: Google
See more images in google
Tuesday, July 26, 2011
Water Supply and Various Types of Pipes
Water supply is the process of general requirement for supply of water from public water supply system to individual building and subsequent distribution of water to various parts of the building. The water from public water supply system to individual buildings is supplied through pipes. A large proportion of capital is invested on pipes while designing water supply distribution system. The following factors should be considered in selection of pipes.
• Strength of pipe
• Water carrying capacity
• Life and durability of pipe
• Expenditure on transportation
• Jointing process, maintenance and repairs.
CI Pipes - Strong and heavy.
CI pipes are heavy in weight. Therefore transportation is costlier and they are not suitable for inaccessible places. Due to heavy weight these are generally made in short length. This increases layout and jointing cost. CI vertical casting pipes are not of very good quality and can be replaced by centrifugal casting (spun casting) pipes.
Steel Pipes
These pipes are extensively used for water supply. They are best suitable for long distance pipe lines of high pressure and provide satisfactory performance during service. These pipes have excellent mechanical properties and are ideally suited for welding. The pipes are made in length more than twice the length of CI pipes; which saves in transport, layout of pipe and joining cost. There is minimum damage to the pipes in transportation. The pipes being light in weight are used for large diameter pipe lines.
Cement Pipes
Main advantage of cement pipes in place of metallic pipes is their corrosion resistance. These pipes are bulky, heavy and require careful transportation and handling. The layout process of these pipes is costlier than steel pipes.
Asbestos Cement (AC) Pipes
These pipes are light in weight and easy in transportation and layout. They have smooth internal surface and are not affected by corrosion (rust). The pipes are extensively used for water supply systems. Holes can be drilled in these pipes. These pipes are not costlier.
Un-plasticized PVC (UPVC) Pipes
These pipes are rigid PVC pipes. They are light in weight, tough, resistant to chemical attack and large in length. Due to large in length the cost of handling is much whereas transportation and installation cost is less. Smooth internal surface of pipes provide less friction which results in saving of energy. These pipes are not suitable for the area which is very hot.
Source:http://www.gharexpert.com
Go to site
• Strength of pipe
• Water carrying capacity
• Life and durability of pipe
• Expenditure on transportation
• Jointing process, maintenance and repairs.
CI Pipes - Strong and heavy.
CI pipes are heavy in weight. Therefore transportation is costlier and they are not suitable for inaccessible places. Due to heavy weight these are generally made in short length. This increases layout and jointing cost. CI vertical casting pipes are not of very good quality and can be replaced by centrifugal casting (spun casting) pipes.
Steel Pipes
These pipes are extensively used for water supply. They are best suitable for long distance pipe lines of high pressure and provide satisfactory performance during service. These pipes have excellent mechanical properties and are ideally suited for welding. The pipes are made in length more than twice the length of CI pipes; which saves in transport, layout of pipe and joining cost. There is minimum damage to the pipes in transportation. The pipes being light in weight are used for large diameter pipe lines.
Cement Pipes
Main advantage of cement pipes in place of metallic pipes is their corrosion resistance. These pipes are bulky, heavy and require careful transportation and handling. The layout process of these pipes is costlier than steel pipes.
Asbestos Cement (AC) Pipes
These pipes are light in weight and easy in transportation and layout. They have smooth internal surface and are not affected by corrosion (rust). The pipes are extensively used for water supply systems. Holes can be drilled in these pipes. These pipes are not costlier.
Un-plasticized PVC (UPVC) Pipes
These pipes are rigid PVC pipes. They are light in weight, tough, resistant to chemical attack and large in length. Due to large in length the cost of handling is much whereas transportation and installation cost is less. Smooth internal surface of pipes provide less friction which results in saving of energy. These pipes are not suitable for the area which is very hot.
Source:http://www.gharexpert.com
Go to site
Design of Coastal Revetments, Seawalls, and Bulkheads
Design of Coastal Revetments,
Seawalls, and Bulkheads
Chapter 1
Introduction
1-1. Purpose
This manual provides guidance for the design of coastal
revetments, seawalls, and bulkheads.
1-2. Applicability
This manual applies to HQUSACE elements, major
subordinate commands, districts, laboratories, and field
operating activities having civil works responsibilities.
1-3. References
Required and related publications are listed in Appendix A. Bibliographic items are cited in the text by author
and year of publication, with full references listed in
Appendix A. If any reference item contains information
conflicting with this manual, provisions of this manual
govern.
1-4. Background
Structures are often needed along either bluff or beach
shorelines to provide protection from wave action or to
retain in situ soil or fill. Vertical structures are classified
as either seawalls or bulkheads, according to their function, while protective materials laid on slopes are called
revetments.
a. Revetments. Revetments are generally constructed
of durable stone or other materials that will provide sufficient armoring for protected slopes. They consist of an
armor layer, filter layer(s), and toe protection. The armor
layer may be a random mass of stone or concrete rubble
or a well-ordered array of structural elements that interlock to form a geometric pattern. The filter assures drainage and retention of the underlying soil. Toe protection is
needed to provide stability against undermining at the
bottom of the structure.
b. Bulkheads and seawalls. The terms bulkhead
and seawall are often used interchangeably. However, a
bulkhead is primarily intended to retain or prevent sliding
of the land, while protecting the upland area against wave
action is of secondary importance. Seawalls, on the other
hand, are more massive structures whose primary purpose
is interception of waves. Bulkheads may be either cantilevered or anchored (like sheetpiling) or gravity structures (such as rock-filled timber cribs). Their use is
limited to those areas where wave action can be resisted
by such materials. In areas of intense wave action, massive concrete seawalls are generally required. These may
have either vertical, concave, or stepped seaward faces.
c. Disadvantages. Revetments, bulkheads, and
seawalls mainly protect only the upland area behind them.
All share the disadvantage of being potential wave reflectors that can erode a beach fronting the structure. This
problem is most prevalent for vertical structures that are
nearly perfect wave reflectors and is progressively less
prevalent for curved, stepped, and rough inclined structures that absorb or dissipate increasing amounts of wave
energy.
1-5. Discussion
The designer is responsible for developing a suitable solution which is economical and achieves the project’s
purpose (see EM 1110-2-3300). Caution should be exercised, however, when using this manual for anything
beyond preliminary design in which the primary goal is
cost estimating and screening of alternatives. Final design
of large projects usually requires verification by hydraulic
model studies. The construction costs of large projects
offer considerable opportunities for refinements and possible cost savings as a result of model studies. Model
studies should be conducted for all but small projects
where limited budgets control and the consequences of
failure are not serious.
Source: http://140.194.76.129/publications/eng-manuals/em1110-2-1614/basdoc.pdf
Read more and go to website
Seawalls, and Bulkheads
Chapter 1
Introduction
1-1. Purpose
This manual provides guidance for the design of coastal
revetments, seawalls, and bulkheads.
1-2. Applicability
This manual applies to HQUSACE elements, major
subordinate commands, districts, laboratories, and field
operating activities having civil works responsibilities.
1-3. References
Required and related publications are listed in Appendix A. Bibliographic items are cited in the text by author
and year of publication, with full references listed in
Appendix A. If any reference item contains information
conflicting with this manual, provisions of this manual
govern.
1-4. Background
Structures are often needed along either bluff or beach
shorelines to provide protection from wave action or to
retain in situ soil or fill. Vertical structures are classified
as either seawalls or bulkheads, according to their function, while protective materials laid on slopes are called
revetments.
a. Revetments. Revetments are generally constructed
of durable stone or other materials that will provide sufficient armoring for protected slopes. They consist of an
armor layer, filter layer(s), and toe protection. The armor
layer may be a random mass of stone or concrete rubble
or a well-ordered array of structural elements that interlock to form a geometric pattern. The filter assures drainage and retention of the underlying soil. Toe protection is
needed to provide stability against undermining at the
bottom of the structure.
b. Bulkheads and seawalls. The terms bulkhead
and seawall are often used interchangeably. However, a
bulkhead is primarily intended to retain or prevent sliding
of the land, while protecting the upland area against wave
action is of secondary importance. Seawalls, on the other
hand, are more massive structures whose primary purpose
is interception of waves. Bulkheads may be either cantilevered or anchored (like sheetpiling) or gravity structures (such as rock-filled timber cribs). Their use is
limited to those areas where wave action can be resisted
by such materials. In areas of intense wave action, massive concrete seawalls are generally required. These may
have either vertical, concave, or stepped seaward faces.
c. Disadvantages. Revetments, bulkheads, and
seawalls mainly protect only the upland area behind them.
All share the disadvantage of being potential wave reflectors that can erode a beach fronting the structure. This
problem is most prevalent for vertical structures that are
nearly perfect wave reflectors and is progressively less
prevalent for curved, stepped, and rough inclined structures that absorb or dissipate increasing amounts of wave
energy.
1-5. Discussion
The designer is responsible for developing a suitable solution which is economical and achieves the project’s
purpose (see EM 1110-2-3300). Caution should be exercised, however, when using this manual for anything
beyond preliminary design in which the primary goal is
cost estimating and screening of alternatives. Final design
of large projects usually requires verification by hydraulic
model studies. The construction costs of large projects
offer considerable opportunities for refinements and possible cost savings as a result of model studies. Model
studies should be conducted for all but small projects
where limited budgets control and the consequences of
failure are not serious.
Source: http://140.194.76.129/publications/eng-manuals/em1110-2-1614/basdoc.pdf
Read more and go to website
Weather update for 26 July 2011
Go to PAGASA DOST website
Issued at: 5:00 p.m., 26 July 2011
At 4:00 p.m. today, Tropical Storm "JUANING" was estimated based on radar, satellite and surface data at 50 km Northeast of Daet, Camarines Norte (14.4°N 123.4°E) with maximum sustained winds of 75 kph near the center and gustiness of up to 90 kph. It is forecast to move West Northwest at 15 kph.
Go to PAGASA DOST website
Issued at: 5:00 p.m., 26 July 2011
At 4:00 p.m. today, Tropical Storm "JUANING" was estimated based on radar, satellite and surface data at 50 km Northeast of Daet, Camarines Norte (14.4°N 123.4°E) with maximum sustained winds of 75 kph near the center and gustiness of up to 90 kph. It is forecast to move West Northwest at 15 kph.
Go to PAGASA DOST website
Subscribe to:
Posts (Atom)
Create your Paypal Account
