300+ [MOSK ASKED] L&t Civil Engineer Interview Questions and Answers

1. What Does Civil Engineering Mean?

They do many interesting things. Their job has to do a lot with design and construction. They can tell you what works and what will not for all sorts of situations. There is a lot of mathematics involved along with many other disciplines. They have to have a good solid understanding of how the environment works and how nature interacts with man made. They are probably best known for designing bridges, interstates, skyscrapers, canals, and so forth.

2. How Did The Rom Get Water Up Hills Using Aqua Ducts?

Technically, the Rom were not able to get water to move uphill in a general sense. All aqueducts move water from an elevated source (spring-fed streams in the mountains) to end-users at a lower elevation. The water flows almost entirely downhill from the source to the end user. If the water needed to cross a valley, the Rom would build an arched structure with an elevated channel to cross the valley, but even this channel would have a vary slight downhill gradient that allowed water to flow towards the end user. If a large hill was in their way, the Rom would either divert the channel around the hill, dig a trench through the hill, or dig a tunnel through the hill, all while maintaining a fairly constant, slight downhill gradient towards the end user.

The only exception to the rule of a generally constant downhill slope to the water channel is that specific tunnel segments, the Rom could build the tunnel as an inverted siphon (mentioned above) to cross a depression or valley and raise the water level on the downhill side almost to the level of the uphill side. To do this requires a well-sealed tunnel strong enough to withstand the increased water pressure within the siphon. Note, however, that except for gaining a little bit of elevation if you slow down fast-moving water, you normally cannot get water to flow out of the outlet at a higher elevation than the inlet. So technically, even the Rom were not able to get water to flow “up a hill”.

3. How Many Lbs Are There In A Yard?

A pound (Lb) is a unit of measurement for weight while a yard is a unit of measurement for distance.

If you are referring to common measurements used on a construction site, a “yard” is a common abbreviation for a “cubic yard”, which is a unit of measurement of volume. (A cubic yard equals 27 cubic feet.)

Since dirt weighs about 110 pounds per cubic feet, a cubic yard of dirt weighs about 2970 Lbs. Since concrete is heavier (150 PCF), a cubic yard of concrete weighs about 4050 Lbs.

4. How Do You Compute The Volume Of Airflow?

Orifice meter is used for measuring flow rate air.

5. How Did Street Originate In The Plumbing Term Street Ell?

A “street ell” may have gotten its name because it describes a 90° fitting PArticularly useful in tight, street ditches. When installing water pipes under a street, or from a water service, again under the street, into a home or business, this street ell allows one to change pipe direction with one less fitting, and in less sPAce, than with a standard ell.

6. What Is The Formula For Figuring Out How Many Gallons Of Water Are In A Pipe By The Foot?

0.61 * d2, where d is the diameter of the pipe in inches.

7. How Is The Leaning Tower Of Pisa Supported?

In the same manner, it was supported when it was constructed. However, it has gotten some “help” over the years.

In the last couple of decades, the responsible PArties rolled up their sleeves and removed something approaching 40 meters3 of earth from under the higher side of the structure. This had the effect of straightening it toward the vertical by about a foot and a half at the top. For the first time in its history, it is no longer moving. In addition, in the good-news corner of the PAper is that it is open to the public again. In addition, the folks who lived near the tower in the direction it was leaning have returned to their homes and do not have to sleep with an eye and an ear open.

8. What Is The Meaning Of A Blue Land Surveyors Flag?

If the flag was placed by Utility personnel responding to a “One-call” locate request, the blue flag indicates a buried water line. You see these marked when a contractor calls the “Call before you dig number” a couple of days prior to excavating. This is required by law in each state to reduce the likelihood of damaging underground utilities when excavating.

The standard color code used by almost all utility comPAnies for PAinting & flags is:

White – “Here is the area I plan on excavating!”

Blue – water line

Red -electricity

Yellow -natural gas

Green -sewer

Orange -telephone and/or fiber optic line

If the blue flagging was a fuzzy blue marker nailed to the top of a wood surveyor’s stake, then it probably serves to indicate the top of the grade at which the engineer wants the earthmoving equipment to place fill dirt. These are called “blue-top” stakes.

9. What Is The Meaning Of Soil Reinforcement?

Soil reinforcement is the act of improving soil strength to enable it support or carry more load.

10. The Foundations Are Placed Below Ground Level, To Increase?

stability of structure.

11. What Black Man Invented The Clothes Dryer?

George T. Sampson

12. How Many Pyramid In Egypt?

About 80

13. What Is Unit Weight Of Normal Concrete?

145 PCF

14. What Are The Applications Of Modulus Of Elasticity?

As the term implies, “Modulus of Elasticity” relates to the elasticity or “flexibility” of a material. The value of modulus of elasticity is very much significant relating to deflection of certain materials used in the construction industry. Take for example the general E value of mild carbon steel is about 200 GPA comPAred to about 70 GPA for aluminum. This simply trlate that aluminum is 3 times flexible than steel.

15. Which Architectural Movement Is Also Known As Jazz Moderna?

Art nouveau

16. Minimum Size Of The Particles Of Silt Soil, Is/

0.002 mm

17. What Is The Difference Between Qa And Qc?

Many people and organizations are confused about the difference between quality assurance (QA), quality control (QC), and testing. They are closely related, but they are different concepts. Since all three are necessary to manage the risks of developing and maintaining software, it is important for software managers to understand the differences.

They are defined below:

a) Quality Assurance: A set of activities designed to ensure that the development and/or maintenance process is adequate to ensure a system will meet its objectives.

b) Quality Control: A set of activities designed to evaluate a developed work product.

c) Testing is the process of executing a system with the intent of finding defects. (Note that the “process of executing a system” includes test planning prior to the execution of the test cases.)

18. What Is The Purpose Of The Gap In The Road On This Bridge?

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.

19. The Concrete Slump Recommended For Beams And Slabs; Is?

30 to 125 mm

20. What Is The Biggest Dam In America?

The Grand Coulee Dam – Grand Coulee, Washington

a) Length 5,223 ft

b) Height 550 ft

21. How Do You Compute Volume Of Airflow?

Orifice meter is used for measuring flow rate air.

22. What Is A Projection Line?

Projection line is the way, in which the earth is shown on a flat piece of PAper.

23. What Is The Tensile Strength Of Wood?

The tensile strength of a material is the value at which the material fails when subjected to a tensile force. (Tensile me a force pulling the wood fibers lengthwise, as opposed to a compressive force.) There are a lot of different types and load cases for wood, so there is not one wer to this question. For example, wood used outside will fail at a lower load than wood inside. Wood is also anisotropic, i.e. it has different strength in different directions.

Example values of tensile strength vary anywhere from 175 pounds per square inch for Utility Grade pine to 1400 PSI for Dense Select Structural grade Douglas Fir. A good reference for material strength data for most species and grades of commercially available wood can be found in the American Institute of Timber Construction handbook.

24. Will Water Damage Concrete?

As far as only concrete is concerned i.e. plain concrete, the effect of water seePAge is very little (depending upon the grade of concrete) whereas for RCC (reinforced cement concrete) water that seeps in corrodes the reinforcement and thus reduces the life of the structure. The defects that water seePAge induces in concrete are as follows:

a) induces capillary formation (due to the detiorating characteristics of water)

b) With this capillaries the concrete starts sPAlling out; i.e. the places where capillaries are formed, with even slight amount of stress that portion comes out and exposes the steel to the atmosphere

c) Concrete has a pH of about 12 -@It also reduces the pH of the concrete when in salty water (or) when exposed to marshy areas.

d) Reduces the overall strength of concrete

e) Reduces durability

f) Reduces permeability to further water seePAge

g) Results in ageing of structures

25. The Portion Of A Brick Cut Across The Width Is Called?


26. What Is The Ratio Of Grades M5, M7.5, M10, M15, M20, M25, M30, M35, M40?

M5 – 1:5:10

M7.5 – 1:4:8

M10 – 1:3:6

M15 – 1:2:4

M20 – 1:1.5:3

M25 – 1:1:2

M30, M35, M40 – Design Mix Followed

27. What Are Advancements In Civil Engineering?

Unlike other fields of engineering, the major advancement of the filed has been in the early years of the century before the last century where the use of concrete technology is advanced. The use of cement as a construction material is since the turn of the last century, improvement in the field increase by the use of steel elements in the construction of buildings and bridges of various types. With the help of two, it was possible to do multistory buildings in the world.

Machineries were created to speed up the construction structures. The last century has also seen the advent of sophisticated design to withstand the effect of earthquake that was not possible before. With the use of computers, development of model and analysis of structures under the effect of loads was made possible. Before just two decades, it used to take months and months to design high-rise building and big bridges. Now it is a matter of hours.

28. Explain The Various Stages Of The Project Planning Process In Construction?

First stage could be Briefing and Inception.

29. What Is The Origin Of Name Railway Sleepers?

When sleepers were added below the railway, lines the trains ran more smoothly and people fell asleep on their journeys.

30. What Is The Difference Between Shear And Tensile Strength?

Tensile Strength for a Bolt is determined by applying a Force along it long axis. Shear Strength for a Bolt is determined by applying a Force across its diameter, as it would be loaded in a lug joint.

31. What Is The Tensile Strength Of Marble?

Tensile Strength, Ultimate 7.00 – 20.0 MPA 1020 – 2900 PSI

this is the strength in a pure tension test. For bending use:

Modulus of Rupture 0.00410 – 0.0276 GPA 0.595 – 4.00 ksi

32. What Are The Materials Used In Building A Gravity Dam?

There are many gravity dams constructed of comPActed earth. High dams are generally concrete. All dams require a spillway to be safe. The spillway must be armored.

33. What Are The Advantages And Disadvantages Of Lead Products In Construction?

Disadvantages: –Lead is very toxic; its use can result in pollution of the ground and more importantly of water supplies. This leads to the contamination of drinking water and can cause hazards to human health as well as disrupting entire ecosystems.

Advantages: Because of its toxicity, lead is being bought less and less around the world, which of course results in the lowering of its cost. In addition, lead melts at a relatively low temperature, making it great for solder. However, recently the Chinese have show an interest in buying mass quantities to manufacture batteries made from a base of lead so the price of this metal may soon rise.

34. What Is Diversion Tunnel In A Dam?

When a dam is to be built, a diversion tunnel is usually bored through solid rock next to the dam site to byPAss the dam construction site. The dam is built while the river flows through the diversion tunnel.

35. Why Is The Statue Of Liberty Made Of Copper?

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.

36. What Is An Ice Dam Sock?

If you have never used a ice dam melting sock on your roof before, you will find that they provide an inexpensive method for removing roof ice dams and improving your home’s heating efficiency. Roof ice dams are an annoying source of roof damage, leaks, and heat loss in the winter. The main causes are drip melt from improperly capped warm air vent pipes and poor roof insulation. Laying a ice melt sock onto the roof so it crosses the ice dam and overhangs the gutter, will melt through the snow and ice and create a channel for water to flow down into the gutters or off the roof. If done properly those ice sickles that form as the snow melts from the edges of the gutters will never appear, they too are a cause of much damage and are dangerous to life and limb.

37. How High Should The Water Tank Be To Provide A 60 Psi At Base Of This Water Tower?


2.31ft of water= 1 PSI

38. How Much Does The Leaning Tower Of Pisa Lean?

About 14 feet

39. What Is Kn Measurement?

kn (both letters lowercase) is knots, which is a speed nautical miles per hour.

40. What Is The Absolute Pressure Scale?

Absolute pressure is calculated from a vacuum (0 PSI) and atmospheric pressure is14.7PSIa or 14.7 PSI above a vacuum 1PSI on a tire pressure gauge is called 1PSIg = 15.7PSIa 10PSIg=24.7PSIa 100PSIg=114.7PSIa etc.

41. How And Where Are Aqueducts Built?

Aqueducts are built in areas where you have a bunch of motivated end users (like a town or group of farmers) at a low elevation in need of a more reliable source of water located somewhere fairly nearby at a higher elevation. The aqueduct builders construct a series of canals, elevated channels, and tunnels as required to get the water from the source to the end users. Some good examples:

  •  Roman engineers built aqueducts throughout Italy and France from mountain water sources to serve city dwellers
  •  Water-needy Southern California cities and farms are served by an aqueduct that brings them water from sources in Northern California
  •  New York City is supplied by an aqueduct and tunnel system from sources upstate.
  • Inca farmers in coastal valleys built irrigation aqueducts from sources higher up in the Rockies
  •  Native American cultures in Phoenix area built irrigation canal systems that diverted water from sources at higher elevations to irrigate their crops.

42. Where Is The Worlds Longest Elevator And How Long Is It?

Gold mines in South Africa go a few kilometers below the surface. The deepest mine now is the Mponeng Mine in the Orange Free State. The depth of the mine is well over 3000m from the surface and is getting deeper. The lift itself descends 3037m to a point 1200m below sea level. It takes 4 minutes.

43. What Is The Strongest Bridge For A School Contest?

If you are making a spaghetti bridge, bunch it all together in a triangular prism or a big brick and just fill the gaps with Paste.

44. What Are Some Facts About Concrete?

Actually, drying is not directly linked to hardness in concrete. After concrete is poured, putting it in a wet environment by spraying it constantly with water will hasten its hardening and its curing. After concrete cures, it is hard.

45. Who Built The Sears Tower?

While he did not build the structure (he died in l959), there is some evidence the idea was suggested under a different name (Illinois Building) by Frank Lloyd Wright, one of the few true skyscrapers in which he had a role. The original design for the Illinois Building would have topped off at 5,280 Feet! The Swears tower is a quarter of this at most, but there are similarities.

46. What Is Horizon Or Horizontal Mining?

Horizon or horizontal mining can be applied to extraction of material from seams of any stratified mineral such as limestone or ironstone, but it is more usually associated with coal – PArticularly where there are several seams that are inclined or folded and/or faulted.

Horizon mining involves long level roadways (horizons) being driven from the shafts to the extremity of the area to be mined.

The levels of the horizons are chosen to intersect the maximum number of seams the maximum number of times. As the seams are intersected, headings will be driven into the seam so that the desired material may be extracted. This method of mining requires a thorough understanding of the geological structure of the area to be mined so that the level of the horizons can be chosen for optimum results.

This method of mining is popular in modern coalmines with seams worked from several horizons. The considerable capital outlay of driving horizons before production can begin is recouped by the advantage of having long straight level roadways of generous dimensions unaffected by the crushing effect of nearby extraction of the mineral.

47. Does Brick Grows Bigger Every Year.

Usually bricks do not grow, but since stuff gets all over, it looks like it grows.

48. Why Does The Pressure Increase Under Soil?

Soil pressure increases with depth due to the overburden or self-weight of the soil and due to loads imposed upon the soil.

For example, the pressure variation below the depth of soil is linear and the relation is given by pressure = unit wt * depth. As depth increases, there will be a linear increase in the soil pressure.

49. What Is Rigging?

In sailing, the ropes used to move the sails around so the boat will move in the right direction when the wind blows.

50. What Are Some Structures That May Be Subjected To Fatigue?

Bridges, hydraulic presses, burners trains.