Question No: 01
What is rigging?
Answer: In sailing, the ropes used to move the sails around so the boat will move in the right direction when the wind blows.
Question No. 02
What are the considerations in selecting marine plants and land plants for installation of band drains?
Answer: For installation of band drains by marine plants, it must have sufficient water depth to accommodate the marine plants in the first place. However, due to the effect of tides and waves, the establishment of the position for installation of band drains and the subsequent installation works may be affected. In addition, the establishment cost of marine plants is higher than that of land plants.
For installation of band drains by land plants, difficulty may be encountered during the installation of band drains through the reclaimed layer e.g. C&D material. Land plants may take longer construction time due to the above-mentioned difficulty. Sometimes when the supply of public fill is increased suddenly, it may be preferable to place these fill immediately into position and in this situation the installation of band drains (originally installed by marine plants) is delayed so that the construction of band drains is changed to using land plants.
Question No. 03
What is the distance between railway tracks?
In U.S, its 4 feet and 8.5 inches In India, its 5 feet 6 inches
Question No. 04
Why are most marine piles circular in cross section?
Answer: For marine piles, there are several options available for selection, namely H-piles, circular pipes and box piles. However, only circular piles and box piles are suitable for marine application because of the following two reasons suggested by G. M. Cornfield (1968):
(i) Circular piles and box piles possess high column buckling strength. For marine structures like jetties, piles are well above seabed level and therefore the column buckling effect is significant when compared with other structures. Therefore, it is essential to use pile sections which have relatively high buckling strength in piers.
(ii) Circular piles and box piles display high energy absorbing capability. For marine structures like dolphins and fenders, which require substantial amount of berthing energy to be absorbed, these piles sections are inevitably good choices. In marine structures, it appears that circular sections prevail over the box sections. The main reason is that the range of section available for selection of circular piles is more than that of box piles.
Question No. 05
What is the purpose of the gap in the road on this bridge?
Answer: Purpose of the gap in the road is to allow the road to expand and contract with temperature changes without causing damage or deformation to the road.
Question No. 06
What is the mechanism of cavitation in pipes and drains?
Answer: Cavitation refers to the formation of air bubbles in fluid in low-pressure condition which is lower than the saturation pressure. It is a potentially damaging condition in which the fluid in pipes or sewers in high velocity. By bernouli equation at high flow velocities, the pressure head of fluid is reduced accordingly. As the fluid pressure is less than saturation pressure, dissolved gases are released from the fluid and these air bubbles will suddenly collapse when the flow enters into a region of higher pressure. This produces a high dynamic pressure which causes damage to the pipelines due to its high frequency.
Question No. 07
What is the importance of geo-textiles and sand in reclamation works?
Answer: For geo-textiles used in reclamation, they serve mainly the following two purposes:
(i) They separate reclamation fill from marine mud;
(ii) They may act as reinforcement to enhance the stability of reclamation. However, the reinforcement function is still under heated debate because its performance as reinforcement depends on several factors like the directional strength of woven geo-textiles and damage effect by installation of vertical band drains.
(i) It spreads the load of future public dump on top of it;
(ii) It acts as drainage path for dissipation of excess pore water pressure for band drain installation.
Question No. 08
Why is the statue of liberty made of copper?
Answer: Copper is a very durable material when exposed to weather and is soft enough that it can be easily molded to curved shapes such as those in the Statue of Liberty. It is also traditionally used in buildings for complex roofs, so there would have been trades people available trained to use it. Other metals that can be molded are lead but it does not have the attractive verdigris color, and gold much is more expensive
Question No. 09
Why is shallow bedrock condition unfavourable for open berth piers?
Answer: The most severe load on piers generally is the horizontal load due to berthing of large vessels. Since the widths of open berth piers are relatively small so that they provides a short lever arm to counteract the moment induced by berthing loads. Moreover, the dead load of open berth piers are normally quite light and therefore the resisting moment provided by the dead load of pier structures may not be sufficient to counteract the moment generated by berthing loads. To aid in providing adequate resistance to the overturning moment by the berthing load, the soil resistance above bedrock contributes to stabilizing moment. For commonly adopted marine piling
type, i.e. driven steel tubular piles with reinforced concrete infill, driven piles can at most be founded on top of rock-head surface. In case the rock-head level is shallow, then the little soil cover may result in insufficient lateral resistance to the berthing load.
Question No. 10
Where is the worlds longest elevator and how long is it?
Answer: Gold mines in South Africa go a few kilometers below the surface. The deepest mine now is the Mponeng, is a gold mine in South Africa’s North West Province. It extends over 4 kilometres below the surface, and is considered to be one of the most substantial gold mines in the world. The lift itself descends 3037 m to a point 1200 m below sea level.