A penstock is commonly used to control the flow and water level and for isolation of fluid. It mainly consists of a sliding door which is controlled by mechanical spindle moving through a hole in a frame built onto a structure. Penstock is the term used in UK while sluice gate is more commonly adopted outside UK. In the design of penstock, it is important to identify if it would take on-seating head or off-seating head.

On-seating head refers to the water pressure forcing the penstock into the wall while off-seating head refers to the water pressure forcing the penstock out of the wall as shown below.

This question is taken from book named – A Closer Look at Prevailing Civil Engineering Practice – What, Why and How by Vincent T. H. CHU.

During the construction of new pavement, vibratory roller and heavy equipment are needed to compact the filling material and bituminous material. These heavy equipment could generate very high impact load with short duration on the concrete pipes. It requires an extremely even and uniform support in order to safely support these loads. Therefore, it is not uncommon that construction vehicles are primary source of crack-producer and it usually results in the formation of circumferential cracks.

This question is taken from book named – A Closer Look at Prevailing Civil Engineering Practice – What, Why and How by Vincent T. H. CHU.

Concrete pipes are designed to be uniformly supported along the length to carry vertical loads on its top. They are normally not intended to serve as a beam to carry loads in longitudinal direction under poor ground supports (i.e. high and low spots in bedding). Under cantilever beam action and simply support beam action as shown in the diagram below, circumferential cracks would develop in concrete pipes. Circumferential cracking develops in concrete pipes only when pipe bedding becomes non-uniform. Therefore in unstable ground conditions such as soft spot and hard foundations, care should be taken to provide firm and even support to concrete pipes.

This question is taken from book named – A Closer Look at Prevailing Civil Engineering Practice – What, Why and How by Vincent T. H. CHU.

An aqueduct is a structure carries canal water through it and crosses over a natural drainage river or nallah. An aqueduct is provided when canal bed level is higher than HFL of natural drainage.
In case of open through aqueduct the service road is discontinuous, and during rainy season for inspection of aqueduct site engineer has pass through submersible causeway to downstream side aqueduct. In this case cost of aqueduct and cost of the causeway and service road is to be borne by irrigation department. But during heavy flood the water flow over cause way and it can not be possible to inspect aqueduct for throughout length. Hence closed box aqueduct is proposed in place of existing open trough aqueduct.

A typical type of aqueduct class as a trough in which one case is considered as overhang box trough and other case as single box trough. In both case service road of canal is pass over top of trough maintaining the continuity of road from one end of aqueduct to another end aqueduct. Components of trough are base slab, vertical wall and top slab are designed for both cases and overhang box trough is found economical.

The sub structure of aqueduct such as pier, abutment, and transition wall are also designed. It has been found that cost of structure increase by 25% if closed box trough constructed instead of open box trough. It shows that for continuity of service road from one end to other end of aqueduct structure the increase in construction cost by 25%.

The electrical power obtained from conversion of potential and kinetic energy of water is called Hydroelectric power

PE=WZ

where
PE= potential energy

W =total weight of the water

Z =vertical distance water can fall

Power is the rate at which energy is produced or utilized:
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