UPSSSC JE Civil Mock Test - 3 - Civil Engineering (CE) MCQ

Concepts:

The compressive strength of good Portland cement and standard sand mortar cement at the end of 3 days should not be less than 11.50 N/mm² and that at the end of 7 days should not be less than 17.50 N/mm².

Note:

1. Standard sand is known as Ennore sand and it is obtained from Tamil Nadu. It is used for the preparation of cement mortar. For the preparation of cement mortar, the cement-sand ratio is 1:3 in which one part is cement and 3 part is sand is used.
2. The compressive strength of cement is determined by cube test on cement mortar cubes compacted by means of a vibrating machine with vibration frequency should be 12000 ± 400 vibrations per minute and vibration time is of 2 minutes.

Valuation of building or property is the method of calculating the present marketable cost of a building. Valuation of a building depends on the sort of building, its structure, durability, location, size, shape, width of roads, frontage, types, and quality of building materials used.

Methods of Valuation of Buildings and Properties:
Following are the different methods of valuation of the property,

• Rental Method of Valuation
• Direct comparison with capital value
• Valuation based on profit
• Valuation based on cost
• Development method of valuation
• Depreciation method of valuation

Rental Method of Valuation:

• In this method, net income from the building is calculated by deducting all the outgoings from gross rent. The year’s purchase (Y.P.) value is calculated by assuming a suitable rate of interest prevailing in the market. For example, consider a rate of interest as 7%, the Year’s Purchase = 100/7 = 14.285 years.
• The net income multiplied by the year's purchase gives the capitalized value or the valuation of the property.
• This method is used only when the rent is known or probable rent is determined by inquiries.

Development method of valuation:

• This method is suitable for properties which are under the developmental stage or partially developed and partially undeveloped. For example, if a large place of land is to be divided into plots after provision for roads and other amenities, this method is used. The probable selling price of the plots, the area required for amenities, and other expenditures for development are considered for valuation.
• If a large place of land is required to be divided into plots after providing for roads, parks, etc, this method of valuation is to be adopted. The development method of valuation is also used for properties or buildings which are required to be renovated by making alterations, additions, improvements, etc. The value is calculated based on the anticipated net income generated from the building after renovation work is complete.

Depreciation Method of Valuation:
Based on the depreciation method, the valuation of the buildings is divided into four parts:

1. Walls
2. Roofs
3. Floors
4. Doors and windows

The cost of each part at the present rate is calculated based on detailed measurements. The life of each part is calculated by the formula,

where,
D = depreciated value
r = rate
d = depreciation
n = age of the building in years

Hence statement (i) is true but statement (ii) is wrong.

Laterally Supported Beam:

• When the lateral support to the compression flange is adequate, the lateral buckling of the beam is prevented and the section flexural strength of the beam can be developed.
• The strength of I-sections depends upon the width to thickness ratio of the compression flange.
• When the width to thickness ratio is sufficiently small, the beam can be fully plastified and reach the plastic moment, such sections are classified as compact sections.
• However provided the section can also sustain the moment during the additional plastic hinge rotation till the failure mechanism is formed. Such sections are referred to as plastic section

• When the compression flange width to thickness ratio is larger, the compression flange may buckle locally before the complete plastification of the section occurs and the plastic moment is reached.
• Such sections are referred to as non-compact sections.
• When the width to thickness ratio of the compression flange is sufficiently large, local buckling of compression flange may occur even before extreme fibre yields. • Such sections are referred to as slender sections

As per IS 800: 2007, Clause 8.2.2
Resistance to lateral torsional buckling need not be checked separately (member may be treated as laterally supported) in the following cases:
a) Bending is about the minor axis of the section,
b) Section is hollow (rectangular/ tubular) or solid bars, and
c) In the case of major axis bending, λ LT (as defined herein) is less than 0.4

Other Related Points

As per clause number 8.2 of IS 800: 2007, the non-dimensional lateral-torsional slenderness ratio is given by,

Where,
λ LTis the non-dimensional lateral-torsional slenderness ratio
βb = 1 for plastic section
Zp is the plastic sectional modulus
fy is yield stress of the material
Mcr is elastic critical moment corresponding to lateral-torsional buckling of the beam

Concept:

Correction for slope:

• In a chain survey distance measured between two-point should always be a horizontal plane.
• But sometimes due to slope on-ground measurement taken on the sloping ground, slope correction is required.
• The distance measured along the slope between two stations is always greater than the horizontal distance is known as slope correction.
• This correction is always negative.

Slope correction = h2/2l

Similarly, Correction for slope if angle θ is given

Slope correction = L(1 − Cosθ)

Concept:
Meandering river:

• The formation of successive bends of reverse order may lead to the formation of a complete S curve called Meanders.
• When consecutive curves of reverse order connected with short straight reaches called crossings are developed in a river reach, the river is started to be a meandering river.

Meander parameters:

• Meander length- It is the axial length of one mender, i.e. tangential distance between the corresponding points of the meander.
• Meander belt- It is the distance between the outer edges of clockwise and anticlockwise loops.
• Meander ratio- It is the ratio of meander belt to meander length.
• Tortuosity-It is the ratio of length along the channel to the direct axial length.

For a meandering alluvial river of width W in flood plain, the meander length is about 6W.

Concept:

The torsional equation is given by,

Where, T = Torque in the shaft, J = Polar moment of inertia
G = Shear modulus, θ = Angle of twist in radian, L = Length of the shaft
τ = Shear stress, r = Radius of the shaft
We can also write the relation between torque and shear stress as,

Where, Fos = Factor of safety
d = Diameter of the shaft in m or mm

Calculation:
Given:
T = 50 Nm, τ = 140 MPa, Fos = 2
Now, for calculating the diameter of the shaft, by using the formula

d = 15.38 mm or 16 mm

Concept:
Load on supporting beams:

• The apportioning of gravity loads to the various secondary/primary beams and columns may be done by considering the tributary areas shown below -

• These tributary areas are based on the following assumptions:

1. Gravity loads in any panel are divided among the supporting beams by lines midway between the lines of support
2. The load in each area is transferred to the adjacent support

As per IS 456:2000, cl. 24.5,

The loads on the beams supporting solid slabs spanning in two directions (two-way slab) at right angles and supporting uniformly distributed loads may be assumed to be in accordance with figure (A)

Calculation:
Given,
L_y = 5.5 m
L_x = 4 m
Since,

The given slab is two-way slab.
∴ cl. 25.4 is applicable

Slab area of which load supported by beam A = Area of the portion (2)

Slab area of which load supported by beam B = Area of the portion (1)

(i) Torsion reinforcement shall be provided at any corner where the slab is simply supported on both edges meeting at that corner and is prevented from lifting unless the consequences of cracking are negligible.
(ii) It shall consist of top and bottom reinforcement, each with layer of bars placed parallel to the sides of the slab and extending from the edges a minimum distance of one fifth of the shorter span.
(iii) The area of reinforcement per unit width in each of these four layers shall be three quarters of the area required for the maximum mid-span moment per unit width in the slab.
(iv) Torsion reinforcement equal to half that described above shall be provided at a corner contained by edges over only one of which the slab is continuous.
(v) No torsional reinforcement is required if both the meeting edges are continuous.

Concept:

Assumptions made in Westerguard Theory:

1. Soil is Homogeneous, Anisotropic (as the physical properties along the different directions are different ), and Elastic.
2. Soil is considered as Cohesive as clay.
3. The soil profile is Layered.
4. Poisson's Ratio is considered zero for all practical purposes.
5. The load will act as a point load on the surface.

As per Westergaard’s equation, the vertical stress due to point load at any point Z below soil strata is calculated using the following formula:

Where,
Q is the concentrated Load
Z is the depth where stress needs to be calculated
I_w is the influence factor, which is given as:

r is the radial distance from a point load to depth Z

Concept:

Population Forecasting Method:

The various methods for population forecasting as suitable for that city, considering the growth pattern, are as follows:

1. Arithmetical increase method:

• This method assumed that the population is increasing at a uniform or constant rate.
• It is used for forecasting the population of those large cities which reach the saturation population.
• This method is suitable for a large and old city with considerable development.

2. Geometrical increase method (uniform increase method/ geometrical progression method):

• In this method, the percentage increase in population from decade to decade is assumed to remain constant.
• This method gives higher value and hence should be applied for a young and rapidly increasing city, but only for a few decades.

3. Incremental increase method:

• This method is a combination of both the arithmetic average method & geometrical average method.
• It is suitable for an average size town under the normal condition where the growth rate is found to be in increasing order.

4. Logistic curve method:

• This method is used when the growth rate of the population due to births, deaths, and migrations takes place under normal situations and it is not subjected to any extraordinary changes like an epidemic, war, earthquake, or any natural disaster, etc.

The correct answer is B. higher is the dry density and lower is the optimum moisture content.

In compaction processes, an increase in compactive effort leads to a higher maximum dry unit weight while simultaneously reducing the optimum moisture content. This means that as more effort is applied during compaction, the soil can be packed more densely, achieving a greater dry density, but it also requires less moisture for optimal compaction. The lubrication effect provided by water is crucial, as it allows soil particles to move closer together, but beyond a certain moisture level (the optimum moisture content), additional water does not contribute to density and can actually reduce the effectiveness of compaction.

Details on Other Options:

• A: This option is incorrect because it suggests that higher compactive effort leads to both higher dry density and higher optimum moisture content, which contradicts the established relationship that higher effort reduces the optimum moisture content.
• C: This option is incorrect as it states that both dry density and optimum moisture content decrease with higher compactive effort, which is not consistent with the principle that dry density increases with more compaction.
• D: This option is incorrect because it implies that higher compactive effort results in lower dry density and higher optimum moisture content, which is contrary to the behavior observed in soil compaction.

Conclusion:

Option: B, as the most accurate and relevant option, stands out for its clear representation of the relationship between compactive effort, dry density, and optimum moisture content. Thus, higher is the dry density and lower is the optimum moisture content is the correct choice.

The following documents shall be attached to the contract agreement or bond which should be endorsed and sealed:
1. Title page
2. Index page
3. Tender Notice
4. Tender Form
5. Bill of Quantities
6. Schedule of issue of materials
7. General Specification
8. Detailed Specification
9. Drawing
10. Condition of contracts
11. Special condition

Marshall Mix Design:1
(i) Marshal test is used for designing the bituminous concrete mix for pavement construction

Important PointsMarshall stability and flow:
(i) Marshall stability of a test specimen is the maximum load required to produce failure when the specimen is preheated to a prescribed temperature placed in a special test head and the load is applied at a constant strain (5 cm per minute). during the stability test dial gauge is used to measure the vertical deformation of the specimen. The deformation at the failure point expressed in units of 0.25 mm is called the marshall flow value of the specimen.

Graphical plot:
The average value of each of the above properties is found for each mix with the different bitumen contents. Graphs are plotted with the bitumen content on the x-axis and the following value on the y-axis.
(i) Marshall stability value
(ii) Flow value
(iii) Unit weight
(iv) Percent voids in the total mix
(v) Percent voids filled with bitumen

The bond between steel and concrete is developed due to following reasons:
1. Pure adhesion- Due to gum like property in the products of hydration.
2. Frictional resistance: Due to the surface roughness of the reinforcement and the grip exerted by the concrete.
3. Mechanical resistance: Due to the deformed bars or due to bearing stress against the rib.

Different timbers and their uses are as follows:

Concept:

The different type of estimates and their meaning is mentioned below in the tabulated form:

Castigliano’s first theorem-

• For linearly elastic structures, where external forces only cause deformations, the complementary energy is equal to the strain energy.
• For such structures, Castigliano’s first theorem may be stated as the first partial derivative of the strain energy of the structure with respect to any particular displacement gives the force causing the deflection at that point
• This first theorem is applicable to linearly or nonlinearly elastic structures in which the temperature is constant and the supports are unyielding.

Castigliano’s second theorem-

• The first partial derivative of the total internal energy in a structure with respect to the force applied at any point is equal to the deflection at the point of application of that force in the direction of its line of action.
• The second theorem of Castigliano is applicable to linearly elastic (Hookean material) structures with constant temperature and unyielding supports.

Standard penetration test also gives an idea about the unconfined compressive strength of clayey soil.

From the table provided above, we can see that, when the unconfined compressive strength of the soil is 160 kN/sqm, the soil will be stiff and its N-Value will be between 8 - 16.

Concept:

Earthwork Measurement:

As per IS 1200:1992, Part 1

• Earthwork measurements are done when constructions are provided below the plinth level.
• Earthwork shall be measured in m3 without any allowance for an increase in bulk.
• The volume of earthwork shall be calculated by multiplying length, breadth, and height.
• No separate measurement shall be taken for cleaning of grass or vegetation, setting out profiles, leaving dead-men, electric cables, gas pipe, water pipes, etc.
• The earthwork measured shall be done separately for the following works:

1. Work in or underwater
2. Work in or under the foul station
3. Work under tidal conditions
4. Work in snow

Calculation:

Given data

The square footing of 2m side

Number of footing = 10

Area of footing = 4 m²

The depth of footing

= RL of the ground - RL of the bottom of the footing

= 100 - 98 = 2 m

Hence, The quantity of earthwork in excavation is

= 10 × 4 × 2 = 80 cu.m

Concept:
Consolidation refers to a decrease in the volume of soil associated with an increase in vertical stress.
This increase is caused mainly by applying pressure (surcharge) to the surface or by changing the level of the water (groundwater table) in the soil.
This process occurs only on saturated and fine-grained soils such as clay. The low permeability of this type of soil causes an increase in the pore pressure because the water cannot leave the pores fast enough when the vertical stress increases.
The process is different in coarse-grained soils such as sand given that in this case, the water leaves the pores almost immediately after the vertical stress increases.

Explanation:
OCR is equal to the maximum applied effective stress in past to the maximum applied effective stress in present.
OCR>1 (OVER CONSOLIDATION STAGE)
OCR=1 (NORMAL CONSOLIDATION STAGE)
OCR<1 (UNDER CONSOLIDATION STAGE)
Compressibility depends upon the magnitude of effective stress acting on the soil at that time and soil time and their structure.
The compressibility of the field deposit is slightly greater than that shown by the lab sample.

Assumptions of Terzaghi's theory of consolidation:

• Soil is isotropic and homogeneous
• Soil is fully saturated
• The theory is applicable to the one-dimensional consolidation test for small load increment ratios.
• The soil particles and water in the voids are incompressible. The consolidation occurs due to the expulsion of water from the voids.
• Darcy's law is valid throughout the consolidation process.
• The time lag in consolidation is due entirely due to the low permeability of the soil.

The correct answer is A. Sulphate attack

Sulphate attack on concrete results in a whitish appearance and damage that typically initiates at the edges and corners, leading to cracking and spalling. This occurs due to a chemical reaction between hydration products and sulphates, causing an increase in volume of the cement paste. The formation of Calcium Sulphate (Gypsum) and Calcium Sulphoaluminate (Ettringite) during this process occupies more space than the original compounds, leading to expansion and damage of the concrete structure.

Details on Other Options:

• B: The sea-water effect on concrete primarily impacts its strength, reducing it by about 15% compared to fresh water. This does not align with the specific damage pattern described in the question.
• C: Acid attack involves the leaching of calcium hydroxide from concrete, resulting in increased porosity and reduced strength, which does not match the characteristics of sulphate attack.
• D: Chloride attack mainly causes corrosion of reinforcing steel at high concentrations, leading to expansion and cracking, but does not produce the characteristic whitish appearance associated with sulphate attack.

Conclusion:

Option: A, as the most accurate and relevant option, is distinguished by its specific association with the whitish appearance and damage pattern starting from edges and corners, clearly differentiating it from the other options. Thus, Sulphate attack is the correct choice.

Workability:

• Workability is used to describe the ease or difficulty with which the concrete is handled, transported, and placed between the forms with minimum loss of homogeneity.

Factors affecting workability:

• Water content
• Mix proportion
• Aggregate size
• Shape of aggregates
• Surface texture
• Grading of aggregates
• Admixtures

Aggregate size:

• Fine-grained aggregates have more surface area and therefore require more water to make them workable. Aggregates with coarser particles have less surface area and hence require less water for workable.

Placing time:

• Placing time increases the workability of concrete decreases because some losses of water occur after making fresh concrete. workability of fresh concrete continuously decreases with the passing of time (placing time).

Hence both statements are correct.

Approach: Check the ultimate and limiting bending moment.
Concept:
To know which type of beam need to be used is determined by checking Ultimate bending moment and Limiting Bending moment.
Need for Doubly reinforced reinforcement
i) When depth is restricted
ii) Reversal of stresses.
iii) Subjected to Impact loads
iv) M_U > M_Ulim
M_Ulim = compressive force x lever arm


Where,
Limiting bending moment (M_Ulim)
Ultimate bending moment (M_U )
d is the effective distance

Calculation:
Given,
Grade of concrete M20
Width of beam = 300mm
Depth of the beam = 400mm
Grade of steel is Fe415
Ultimate bending moment (M_U) = 150kN-m
Limiting bending moment (M_Ulim )

kN-m

= 132.48 kN-m
∴ M_U > M_Ulim
∴ Doubly reinforced beam is used.

Explanation :
Rivet value is defined as minimum of shearing and bearing strength of rivet.
Failure in a riveted joint may be occurred due to:
i) Shear failure of the rivet
ii) Bearing failure of the rivet
iii) Tearing failure of the rivet
iv) Bearing failure of the plate
v) Tearing failure of the plate
vi) Block shear failure
Shearing of the rivet: When shear stress in the rivets exceeds the maximum allowable shearing stress then the shear failure of rivets takes place.

Bearing/ Crushing failure of rivet: If bearing stress on the rivet is too large so that contact surface between rivet and plate may get damaged this is called crushing or bearing failure of rivet.

Important Points The strength of a riveted joint is equal to its least of shearing strength, bearing strength and tearing strength.∴ The strength of a riveted joint is equal to a minimum of PT, PS, and PB.

Concept:
In railways, the disc signals are provided for the purpose of shunting.

1. When the red band of the disc is in a horizontal position, it indicates “STOP”.
2. When the red band of the disc is in an inclined position, it indicates “PROCEED” slowly for shunting.​

The indications of a disc signal is depicted in following diagram:

Other Related PointsDisc Signals/Shunting Signals:

• The disc signals are in the form of a circular disc with a red band on a white background and these discs can rotate in a vertical plane. By rotating the disc different operations are instructed.
• In railways, disc signals are used to instruct various operations like changing the locomotive of a train, attaching/detaching of wagons, changing the order of wagons, etc. These kinds of operations are collectively known as shunting or shunt moves.

Concepts:

As per IS 2296: 1982, the surface water quality standards are classified into 5 categories which are specified below:

1. Class A – Drinking water without conventional treatment but after disinfection.

1. Class B – Water for outdoor bathing.
2. Class C – Drinking water with conventional treatment followed by disinfection.
3. Class D – Water for fish culture and wild life propagation.
4. Class E – Water for irrigation, industrial cooling and controlled waste disposal.

Concept:
Slabs:
Slabs are considered as plane element or plate elements which are classified based on aspect ratio.
Aspect ratio:
It is defined as ratio between longer span (Ly) of the slab to shorter span (Lx) of the slab.
Aspect ration = L_y/L_x
Types of slab based on aspect ratio
1) One way slab:
Slab spanning in one direction
L_y/L_x > 2
2) Two way slab:
Slab spanning in both the direction
L_y/L_x < 2
Explanation:
Analysis of slab spanning in one direction:
The analysis of slab spanning in one direction is done by assuming it to be a beam of 1 m width, though the slab width is continuous and is not composed of individual beams of 1 m width. The reinforcement are calculated for 1 m width and the bars are distributed accordingly.

Concept:

Air content:

Air content is defined as the ratio of the volume of air to the volume of voids. It is denoted by ac.

or, ac = 1 - Sr

Porosity:

Porosity is defined as the ratio of the volume of voids to the total volume of soil. It is denoted by n. It varies between 0 and 1.

Percentage air voids:

Percentage air voids are defined as the ratio of the volume of air to the total volume of soil. It is denoted by n­­a.

or, = ac × n