CivilAche

  Weather and Climate The basic consideration to distinguish between weather and climate is duration. Alternatively we can say that the difference between weather and climate is measure of time.weather consists of the short-term (minutes, days or months) changes in the atmosphere. However, climate  is the average weather condition over a long time(years, decades or centuries) and space or region. Weather Weather can be defined by terms given as: temperature, humidity, precipitation, cloudiness, brightness, visibility, wind, and atmospheric pressure (as in high and low pressure) and in most places, it can change from minute-to-minute, hour-to-hour and day-to-day. So as definition we can say that the short term atmospheric condition of any place is the weather, which may vary by time-to-time. Weather may restrict transportation services, agricultural activities and other day to day occupations may be affected by weather. We can observe the changes in the weather condition in frequent man

  CANAL INTAKE Canal intake structure An irrigation canal used as the source of water when other source are far from the city. Intake structure constructed near the bank of canal. An intake chamber created inside the canal using concrete or masonry having one bell mouth entry pipe inside it. Intake chamber has opening guarded with coarse screen and bell mouth entry protected with fine screen or mesh. Bell mouth entry located at expected low water level of the canal. Water enters from this bell mouth entry and conveyed through withdrawal conduits to sump well or city.

  LAKE INTAKE Lake intake generally  formed by submerged intake pipe with bell mouth entry placed at the bed of lake where sufficient depth is available. This intake pipe conveys water to the jack well or sump well and from that water is transmitted to treatment plant using pump mechanism. Water conveyed in  intake pipe is under gravity force and mesh provided with entry port to clean water. Sump well constructed near the shore of lake.

  RESERVOIR INTAKE All rivers has not sufficient depth of flow throughout the year and hence dam constructed across the river to form a reservoir having sufficient depth for intake. This intake structure built upstream side near the dam and it is similar to the river intake. A typical reservoir intake well consists number of water entry ports located at various elevations so that relatively clear top water is only drawn at all seasons. All control on this entry ports is at topnof the well. Dry intakes and wet intakes formed according to the position of entry valves outer and inner of the well respectively.

  WET INTAKE Wet intake generally in circular shell type. Tower of intake contains water in side it. This water intake structure tower has water level inside the tower that is practically same as the water level of the source of water.

  DRY INTAKE There is no water in the water tower in the dry type water intake structure. Entry ports are made at different levels so that water can enter in the driest period.  Water enters through entry ports at required level and directly conveyed to the withdrawal pipe. Tower used only for operation purposes does not contain water in it. Operating and maintenance are easy for these types of structures. Dry intake has no water inside the tower so due to outer water buoyant force acts on the structure. Hence the weight of structure is enough to withstand against this buoyant force.

  EXPOSED INTAKE Well constructed near the bank of reservoir or sometimes intake well constructed away from the source of water. Exposed intake structures are easy to handle and more common to use because rare of it's parts are inside the water.

  SUBMERGED INTAKE These intake structures are entirely constructed under water hence called submerged intake structure.  Generally the lake has shallow depth at the bank and center of lake has appropriate depth for intake to draw water so submerged intake provided at center of the lake. We also can say it is as lake intake. It is under the water hence operation and maintenance is quite difficult. 

  RIVER INTAKE As we know intake should be located at the upstream side of the city so pollution is minimum and this river intake should be sufficiently inside the river water so need of water can be supplied at every seasons of the year. Some river intakes are constructed near the bank of river when sufficient depth is available, some are created away from the bank of river when river bed is soft or unstable near bank, sometimes water level raised by constructing weir on the river and sometimes channel created and water led to the intake tower. This all situations divides river intake into two major types: (1) Single well type intake and (2) Twin well type intake. Parts of river intake are Intake well, Intake pipe and Jack well. River intake well has two parts, lower part is Jack well and upper part is surves pump house. SINGLE WELL TYPE RIVER INTAKE In single well type intakes water is directly enter into jack well through the penstockes (openings) created at different level. As this

  INTAKE STRUCTURE Introduction The structure or device constructed in or near the source of water for the purpose of collecting or taking water from the source of water is called INTAKE STRUCTURE. Hence, main use of intake is to draw clear (free from pollution, sand and other floating material) water from surface source of water like river, canal, dam etc. Generally intake structures are constructed from the masonry or concrete. Water entering in the intakes is discharged to the withdrawal conduits from which water is transmitted(conveyed) to the treatment plant. This discharge is safely done either by natural(gravity) flow or by pump to the withdrawal conduits. SITE SELECTION OR LOCATION CRITERIA FOR INTAKE STRUCTURE Quality of water, cost of conveyance or economy, quantity of water, availability of good foundation and land near the water source are some criteria for the section of intake structure site location. Intake must be well located on the upstream side of any city or industr

Beams, Columns and other concrete structures is liable to have cracks in their two states, one in prehardening or plastic state and other in hardened state. Beams and columns with cracks are dangerous as they can no longer able to support design loads. Different conditions of loading and responce of structure shows different cracks formation in structure.  Let's discuss in short cracks in beams and columns; Crack in Beams, 1) Flexure crack When flexural capacity of R C beam is not adequate and cross section of the beam has insufficient main reinforcement or cross reinforcement, flexure cracks may develop in the beam. A single crack or group of crack starts where bending moment is maximum and the maximum width of crack found at bottom or top of the beam. Proper design may eliminate this cracks. 2) Torsion crack, This crack is similar to flexure crack as here torsional capacity and torsion reinforcement is inadequate and hence crack developing at whete torsion moment is maximum. This