Question 1

Q.6 Match the information given in Group - I with those in Group - II.

Group - I
P Factor to decrease ultimate strength to design strength
Q Factor to increase working load to ultimate load for design
R Statical method of ultimate load analysis
S Kinematical mechanism method of ultimate l

Accepted Answer

(C) P-3; Q-4; R-2; S-1. Option C correctly matches the factors with their definitions: P refers to the material partial safety factor, which decreases the ultimate strength to design strength; Q corresponds to the load factor, which increases the working load to ultimate load for design; R represents the lower bound method of ultimate load analysis; and S denotes the upper bound method.

Question 2

For a saturated cohesive soil, a triaxial test yields the angle of internal friction (φ) as zero. The conducted test is

Accepted Answer

Unconsolidated Undrained (UU) test. The Unconsolidated Undrained (UU) test is designed to evaluate the strength of saturated cohesive soils without allowing drainage, which means pore water pressures can affect the results. In this case, a zero angle of internal friction indicates that the soil behaves as a purely cohesive material under undrained conditions, characteristic of the UU test.

Question 3

The action of negative skin friction on the pile is to

Accepted Answer

reduce the allowable load on the pile. Negative skin friction occurs when the soil surrounding a pile moves downward relative to the pile, effectively adding a downward force that reduces the pile's capacity to carry loads. This results in a decrease in the allowable load on the pile, as the negative skin friction counteracts the load the pile can safely support.

Question 4

A long slope is formed in a soil with shear strength parameters: c' = 0 and φ' = 34°. A firm stratum lies below the slope and it is assumed that the water table is occasionally rise to the surface, with seepage taking place parallel to the slope. Use γsat = 18 kN/m³ and γw = 10 kN/m³. The

Accepted Answer

11.3. For an infinite slope with seepage to the surface and c'=0, FS = (gamma'/gamma_sat)*tan(phi')/tan(beta). With gamma'=8, gamma_sat=18, phi'=34deg, FS=1.5: tan(beta)=(8/18)*tan34/1.5=0.200, so beta=11.3deg. The stored 44.7 is wrong; correct is 11.3.

Question 5

A conventional flow duration curve is a plot between

Accepted Answer

Flow and percentage time flow is exceeded. A conventional flow duration curve illustrates the relationship between streamflow rates and the percentage of time that those rates are equaled or exceeded, providing insights into water availability over time.

Question 6

In reservoirs with an uncontrolled spillway, the peak of the plotted outflow hydrograph

Accepted Answer

lies on the recession limb of the plotted inflow hydrograph. In reservoirs with uncontrolled spillways, the outflow typically occurs after the inflow has peaked, meaning the peak outflow will be found on the recession limb of the inflow hydrograph as the reservoir releases water following the inflow peak.

Question 7

The tension and shear force (both in kN) in each bolt of the joint, as shown below, respectively are

[Diagram of a bolted joint with an inclined member carrying P_u = 250 kN; the member inclination is indicated by a 3-4-5 triangle.]

Accepted Answer

33.33 and 25.00. The correct option is right because the tension in each bolt is calculated based on the vertical component of the applied load, while the shear force is derived from the horizontal component, both of which are influenced by the geometry of the inclined member.

Question 8

A horizontal jet of water with its cross-sectional area of 0.0028 m² has a fixed vertical plate with a velocity of 5 m/s. After impact the jet splits symmetrically in a plane parallel to the plane of the plate. The force of impact (in N) of the jet on the plate is

Accepted Answer

70. Force on a stationary flat plate from a normal jet = rho*A*V^2 = 1000 * 0.0028 * 5^2 = 1000*0.0028*25 = 70 N. So the correct value is 70 N (index 2), not 90 N.

Question 9

The potable water is prepared from turbid surface water by adopting the following treatment sequence.

Accepted Answer

Turbid surface water → Coagulation → Flocculation → Sedimentation → Filtration → Disinfection → Storage & Supply. The correct sequence starts with coagulation to remove suspended particles, followed by flocculation to form larger aggregates, then sedimentation to settle these aggregates, filtration to remove remaining impurities, and finally disinfection to kill pathogens before storage and supply, ensuring safe and clean potable water.

Question 10

Group I contains representative stress-strain curves as shown in the figure, while Group II gives the list of materials. Match the stress-strain curves with the corresponding materials.

Group I
P. Curve J
Q. Curve K
R. Curve L

Group II
1. Cement paste
2. Coarse aggregate
3. Concrete

Accepted Answer

P - 2; Q - 3; R - 1. The correct option matches the stress-strain characteristics of each material: Curve J (P) represents the behavior of coarse aggregate, which is typically more linear and less ductile; Curve K (Q) corresponds to concrete, which shows a more complex behavior with a defined yield point; and Curve L (R) reflects the properties of cement paste, which is more brittle and has a lower strength compared to concrete.

Question 11

The target mean strength f_cm for concrete mix design obtained from the characteristic strength f_ck and standard deviation σ, as defined in IS:456-2000, is

Accepted Answer

f_ck + 1.65σ. The correct option, f_ck + 1.65σ, is derived from the need to ensure that the target mean strength accounts for variability in concrete strength, providing a higher safety margin to achieve the desired performance in structural applications.

Question 12

The modulus of elasticity, E = 5000√f_ck, where f_ck is the characteristic compressive strength of concrete, specified in IS:456-2000 is based on

Accepted Answer

secant modulus. The modulus of elasticity formula provided is based on the secant modulus, which represents the slope of the line connecting the origin to a point on the stress-strain curve, reflecting the overall stiffness of concrete under loading.

Question 13

The static indeterminacy of the two-span continuous beam with an internal hinge, shown below, is

Accepted Answer

1. The static indeterminacy of a two-span continuous beam with an internal hinge is determined by the number of reactions minus the number of equilibrium equations available. In this case, the internal hinge allows for one additional degree of freedom, resulting in a static indeterminacy of 1.

Question 14

As per Indian Standard Soil Classification System (IS: 1498 - 1970), an expression for A-line is

Accepted Answer

Iₚ = 0.73 (w_L - 20). The correct option is based on the established formula for the A-line in the Indian Standard Soil Classification System, which accurately reflects the relationship between plasticity index and liquid limit, specifically using the coefficient 0.73 and the constant 20.

Question 15

The clay mineral primarily governing the swelling behavior of Black Cotton soil is

Accepted Answer

Montmorillonite. Montmorillonite is a type of clay mineral known for its high swelling capacity due to its layered structure and ability to absorb water, making it the primary mineral responsible for the swelling behavior observed in Black Cotton soil.

Question 16

A plane flow has velocity components u = x/T₁, v = -y/T₂ and w = 0 along x, y and z directions respectively, where T₁ (≠ 0) and T₂ (≠ 0) are constants having the dimension of time. The given flow is incompressible if

Accepted Answer

T₁ = T₂. The flow is incompressible if the divergence of the velocity field is zero. In this case, setting T₁ equal to T₂ ensures that the contributions from the x and y components of velocity balance out, resulting in a divergence of zero.

Question 17

Group I lists a few devices while Group II provides information about their uses. Match the devices with their corresponding use.

Group I
P. Anemometer
Q. Hygrometer
R. Pitot Tube
S. Tensiometer

Group II
1. Capillary potential of soil water
2. Fluid velocity at a specific point in the fl

Accepted Answer

P - 4; Q - 3; R - 2; S - 1. The correct option matches each device with its specific function: the anemometer measures wind speed, the hygrometer assesses the water vapor content in the air, the Pitot tube determines fluid velocity at a point in a flow stream, and the tensiometer evaluates the capillary potential of soil water.

Question 18

An isolated 3-h rainfall event on a small catchment produces a hydrograph peak and point of inflection on the falling limb of the hydrograph at 7 hours and 8.5 hours respectively, after the start of the rainfall. Assuming no losses and no base flow contribution, the time of concentration (

Accepted Answer

5.5. The time of concentration is defined as the time it takes for water to travel from the most distant point in the catchment to the outlet. Since the peak occurs at 7 hours and the point of inflection on the falling limb at 8.5 hours, the time of concentration is typically estimated as the time to peak minus the time it takes for the hydrograph to start falling, which in this case suggests a value around 5.5 hours.

Question 19

The Muskingum model of routing a flood through a stream reach is expressed as O2 = K0 I2 + K1 I1 + K2 O1, where K0, K1 and K2 are the routing coefficients for the concerned reach, I1 and I2 are the inflows to the reach, and O1 and O2 are the outflows from the reach corresponding to time st

Accepted Answer

1. The sum of the routing coefficients K0, K1, and K2 equals 1 because they represent proportions of inflow that are distributed to the outflow at different time steps, ensuring that the total flow is conserved within the system.

Question 20

The dominating microorganisms in an activated sludge process reactor are

Accepted Answer

aerobic heterotrophs. Aerobic heterotrophs are the primary microorganisms in an activated sludge process because they thrive in oxygen-rich environments, breaking down organic matter and contributing to the treatment of wastewater.

Question 21

The two air pollution control devices that are usually used to remove very fine particles from the flue gas are

Accepted Answer

Electrostatic Precipitator and Fabric Filter. Electrostatic precipitators and fabric filters are specifically designed to capture very fine particles from flue gas through different mechanisms, making them highly effective for air pollution control in industrial applications.

Question 22

The survey carried out to delineate natural features, such as hills, rivers, forests and man-made features, such as towns, villages, buildings, roads, transmission lines and canals is classified as

Accepted Answer

topographic survey. A topographic survey specifically focuses on mapping the physical features of the land, including both natural and man-made elements, which is essential for understanding the terrain and planning developments.

Question 23

Group I enlists in-situ field tests carried out for soil exploration, while Group II provides a list of parameters for sub-soil strength characterization. Match the type of tests with the characterization parameters.

Group I
P. Pressuremeter Test (PMT)
Q. Static Cone Penetration Test (SCP

Accepted Answer

P - 1; Q - 3; R - 2; S - 4. The Pressuremeter Test (PMT) measures the Menard's modulus (Eₘ), which reflects the soil's elastic properties; the Static Cone Penetration Test (SCPT) assesses skin resistance (f_c) to evaluate soil strength; the Standard Penetration Test (SPT) provides the number of blows (N) indicating soil density; and the Vane Shear Test (VST) determines the undrained cohesion (c_u) of cohesive soils.

Question 24

A venturimeter with a throat diameter of 0.1 m is used to estimate the flow rate of a horizontal pipe having a diameter of 0.2 m. For an observed pressure difference of 2 m of water head and coefficient of discharge equal to unity, assuming that the energy losses are negligible, the flow r

Accepted Answer

0.050. A2=pi/4*0.1^2=0.007854, (d/D)^2=0.25 so denominator sqrt(1-0.0625)=0.968. Q=0.007854*sqrt(2*9.81*2)/0.968=0.007854*6.264/0.968=0.0508 m3/s, approx 0.050. Stored 0.015 is wrong.

Question 25

With reference to a standard Cartesian (x, y) plane, the parabolic velocity distribution profile of fully developed laminar flow in x-direction between two parallel, stationary and identical plates that are separated by distance, h, is given by the expression
u = - h²/(8μ) dp/dx [1 - 4(y/h

Accepted Answer

(A) u_max = - h²/(8μ) dp/dx and u_average = 2/3 u_max. The maximum velocity, u_max, is correctly expressed as - h²/(8μ) dp/dx, reflecting the negative gradient of pressure in the flow direction, while the average velocity is derived from the parabolic profile, resulting in u_average being 2/3 of u_max.

GATE Technical: CIVIL - CE questions with solutions

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