Civil Engineering (CE) Technical Mock Test CE (SSC JE)- 4 Free Online Test

The degree of saturation in a partially saturated soil indicates how much of the soil's voids are filled with water. If this degree is 60%, we can find the air content using the following points:

• The total volume of voids consists of both air and water.
• When the degree of saturation is at 60%, it means that 60% of the voids are filled with water.
• Thus, the remaining voids, which represent air, make up the balance.
• To calculate the air content, subtract the degree of saturation from 100%:

Air Content = 100% - Degree of Saturation

In this case:

Air Content = 100% - 60% = 40%

Therefore, the air content of the soil is 40%.

In hydrometer analysis for a soil mass, the corrections applied are as follows:

• Meniscus correction accounts for the curvature of the liquid surface.
• Dispersing agent correction addresses the effects of the chemical agent used to separate soil particles.

The relationship between these corrections can be summarised as:

• Both corrections are made to ensure accurate readings.
• Meniscus correction is additive, meaning it increases the measurement value.
• Dispersing agent correction is subtractive, meaning it decreases the measurement value.

Thus, the correct understanding is that the meniscus correction adds to the reading while the dispersing agent correction subtracts from it.

The hydrometer method of sedimentation analysis primarily differs from pipette analysis in several key areas:

• Principle of Test: Each method operates on different principles, influencing how results are interpreted.
• Observation Method: The technique for recording measurements varies significantly between the two methods.
• Soil Suspension Preparation: The approach to preparing the soil suspension is distinct, affecting the accuracy of the analysis.

These differences imply that each method has unique advantages and limitations in sedimentation analysis.

Rise of water table above the ground surface causes

• When the water table rises, it leads to an equal increase in both pore water pressure and total stress within the soil.

• This phenomenon affects the soil's mechanical properties, as the rising water level pushes water into the pores, increasing the pressure.

• The total stress on the soil includes both the weight of the soil above and the pressure from the water in the pores.

• As a result, the overall condition of the soil changes, influencing its stability and behaviour under load.

In a beam and slab structure, the effective width of the intermediate flange can be determined based on specific dimensions:

• Width of beam: Represented as b_w.
• Depth of slab: Denoted by D_f.
• Distance between points of zero moments: Known as l_o.

The effective width formula incorporates these dimensions, providing a method for calculating the flange width in a beam and slab system. Understanding these terms is crucial for structural analysis and design.

This approach ensures that the structural integrity and load distribution are effectively managed in the design process.

Physical properties influencing permeability include:

• Viscosity: This refers to the thickness of a fluid and its resistance to flow. Higher viscosity means the fluid flows more slowly, which can affect how easily it moves through materials.
• Unit weight: This is the weight of a material per unit of volume. It can impact how fluids interact with solids and their ability to pass through different media.
• Both viscosity and unit weight play a significant role in determining permeability. When both are considered, we can better understand how fluids move through porous materials.

In summary, understanding both viscosity and unit weight is essential for accurately assessing permeability in various contexts.

The phreatic line in an earthen dam is a critical concept in dam engineering and hydrology. It refers to the line that separates saturated soil from unsaturated soil within the dam structure.

• The shape of the phreatic line is typically parabolic.
• This parabolic shape arises due to the flow of water through the soil.
• Understanding this line is essential for:
• Assessing the stability of the dam.
• Determining seepage rates.
• Designing effective drainage systems.
• Other shapes, such as straight, circular, or elliptical, do not accurately represent the phreatic line in most earthen dams.

The time factor for a clay layer is a crucial concept in soil mechanics, which affects how water moves through soil.

• Dimensional parameter: It serves as a key measurement that influences drainage and stability.
• Inversely proportional to drainage path: A shorter drainage path leads to a higher time factor, indicating faster water movement.
• Directly proportional to permeability: The higher the soil's permeability, the less time it takes for water to flow through the clay layer.
• Independent of thickness: The time factor does not depend on the thickness of the clay layer, highlighting that other factors play a more significant role.

This understanding is essential for effective soil management and engineering applications.

Passive earth pressure in a soil mass relates to several key factors:

• Soil Type: Different types of soil, such as clay or sand, exert varying pressures.
• Soil Density: Denser soils produce higher passive earth pressures.
• Depth of Soil: As depth increases, so does the pressure due to the weight of the overlying soil.
• Water Content: Increased moisture alters soil behaviour and may influence pressure levels.

Understanding these factors is essential for accurately assessing passive earth pressure in engineering and construction projects.

A soil with particles that are almost the same size is termed:

• Uniformly graded: This type of soil has particles that are similar in size, leading to a consistent texture.
• Well graded: This soil contains a wide range of particle sizes, which helps in achieving better compaction.
• Poorly graded: This refers to soil with a limited range of particle sizes, leading to voids and less stability.
• Gap graded: This soil includes a range of sizes but lacks certain intermediate sizes, creating gaps within the particle distribution.

The correct classification for soil with nearly the same sized particles is uniformly graded.

The value of permeability in materials is influenced by several factors, including:

• Void ratio: This measures the amount of void space in a soil sample compared to its solid particles. A higher void ratio typically results in increased permeability.
• Degree of saturation: This indicates how much of the void space is filled with water. As saturation increases, permeability can change, typically decreasing when the soil is fully saturated.
• Pressure head: This refers to the height of water above a point in the soil. Changes in pressure head can influence the flow of water through soil, thereby affecting permeability.
• Grain size: The size of soil particles significantly impacts permeability. Larger grains allow for easier water flow, resulting in higher permeability.

Each of these factors plays a crucial role in determining how easily fluids can move through soil or rock, which is essential for understanding various engineering and environmental processes.

Let’s solve this step-by-step:

Given:

• Cohesion, C = 2 t/m²

• Angle of internal friction, φ = 0°

• Unit weight of soil, γ = 2 t/m³

Formula for depth of tension crack:

For cohesive soil (with φ = 0), the depth of tension crack h_tc is given by:

h_tc = (2C) / γ

Substituting the values:

h_tc = (2 × 2) / 2

h_tc = 4 / 2 = 2 m

Final Answer:

The depth of tension crack is 2 meters.

The main principle of surveying is to understand the relationship between parts and the whole. Here are key points to consider:

• Whole to Part: This approach starts by looking at the entire area before examining its individual components.
• Part to Whole: Alternatively, one can begin with specific sections and then integrate them into a broader context.
• Higher Level to Lower Level: This method involves surveying from elevated locations to those below.
• Lower Level to Higher Level: Conversely, this method surveys from lower points upwards.

In surveying, the most effective method is to work from whole to part, as it provides a comprehensive understanding of the area being surveyed.

Shear resistance in reinforced concrete beams is a crucial aspect of structural engineering. When shear forces act on a beam, the vertical component of this shear is resisted by stirrups that are inclined at an angle (α) to the vertical. Understanding how these stirrups function is essential for ensuring the structural integrity of beams. Here’s a breakdown of the concept:

• Stirrups are transverse reinforcements that help hold the main longitudinal reinforcement in place.
• They are designed to carry shear forces, particularly when the shear stress exceeds the capacity of the concrete alone.
• The inclination angle (α) of the stirrups affects their effectiveness in resisting vertical shear.
• As the angle increases, the stirrups provide more vertical support, improving their capacity to resist shear.

In practice, engineers calculate the required spacing and size of stirrups based on the expected shear forces in the beam. This ensures that the structural elements perform safely under load, especially in scenarios where significant shear forces are present.

Correct Answer :- C

Explanation : Actual slope correction is always -ve therefore, 

Correction = - [L(1 - cosθ)].

= (Lcosθ - L).

= L(cosθ - 1) ; now L is 30m chain.

So the answer comes out to be = 30(cosθ - 1) m.

The line normal to the plumb line is known as:

• Horizontal line: A line that runs parallel to the horizon.
• Level line: A line that is perfectly horizontal, indicating a state of balance.
• Datum line: A reference line used in surveying, typically for measuring heights or depths.
• Vertical line: A line that runs straight up and down, perpendicular to the horizontal.

The correct term for the line normal to the plumb line is a level line.

In levelling operation:

• If the first reading is greater than the second reading, it indicates a rise.

• If the first reading is less than the second reading, it indicates a fall.

• If the second reading is less than the first reading, it also indicates a fall.

• Both of the above points reflect the same outcomes.

The staff intercept will be

• The intercept becomes greater as the staff is held farther away.

• The intercept is smaller when the staff is held farther away.

• The intercept is greater when the staff is held nearer to the observer.

• The intercept remains the same regardless of the staff's position.

In a techeometer, the multiplying constant is determined by the relationship between various distances:

• i is the stadia distance.
• f is the focal length.
• d is the distance between the objective and the vertical axis.

The formula to calculate the multiplying constant is:

f / i

Understanding these terms helps in accurate measurements in surveying, where the techeometer is commonly used.

The planimeter is a tool specifically designed for measuring the area of a two-dimensional shape. Here are some key points about its use:

• It is particularly useful in fields such as geography and cartography.
• The device measures irregular shapes by tracing their outlines.
• Planimeters can provide accurate area calculations that are vital for various applications.

Unlike devices that measure volume, contour gradient, or slope angle, the planimeter focuses solely on area measurement.

A point determined by resection on a plane table is known as a planetable fix. This term specifically refers to the method used in surveying to establish a precise location on a map or plan. Here’s a concise breakdown of what this means:

• A planetable fix is achieved by using a plane table, which is a flat surface mounted on a tripod.
• Surveyors take sightings to various known points and triangulate their current position based on these observations.
• This technique allows for accurate mapping and data collection in the field.

Understanding the term is crucial for those involved in surveying and geographical mapping.

Nagpur's road planning involves various patterns to optimise traffic flow and accessibility.

• Rectangular or Block Road Pattern: This design features straight roads that intersect at right angles, creating a grid-like layout. It is easy to navigate and promotes systematic development.
• Radial or Star and Block Road Pattern: Roads radiate from a central point like spokes on a wheel, combining direct routes with a block structure. This pattern enhances connectivity while maintaining order.
• Radial or Star and Circular Road Pattern: In this layout, roads spread out from a central hub with circular routes encircling it. This approach can reduce congestion at the centre and improve traffic distribution.
• Radial or Star and Grid Road Pattern: This combines radial roads with a grid system, offering multiple routes for drivers while facilitating easy access to various areas.

The best choice for the Nagpur road plan is the radial or star and grid road pattern, as it effectively balances traffic flow and accessibility.

The shape of the camber suited for cement concrete pavements is crucial for effective drainage and vehicle safety. The ideal camber shape can be summarised as follows:

• A straight line provides uniform drainage but may not be effective in all scenarios.
• A parabolic shape promotes better water runoff and reduces pooling, making it a popular choice.
• An elliptical form is less common but can offer unique benefits depending on specific pavement conditions.
• A combination of straight and parabolic shapes can optimise water flow and enhance pavement durability.

Each shape has its advantages, but the parabolic design is generally preferred for its efficiency in directing water away from the pavement surface. This can help maintain the integrity of the pavement and improve safety for vehicles.

Desire lines are important in understanding how people navigate spaces. They represent the natural paths that individuals choose, often deviating from planned routes. These lines can be plotted using various studies, including:

• Traffic volume studies: Analyze the number of pedestrians or vehicles using a particular area.
• Speed studies: Measure how quickly people travel along different routes.
• Accident studies: Investigate the locations and causes of accidents, revealing where desire lines may conflict with safety.
• Origin and destination studies: Track where people are coming from and going to, highlighting common routes.

These studies help urban planners and designers create spaces that better accommodate the natural behaviours of users, improving accessibility and functionality.

The maximum width of a vehicle recommended by the Indian Roads Congress (IRC) is:

• 1.85 m - This is generally suitable for smaller vehicles.
• 2.44 m - This width accommodates larger vehicles, such as buses and trucks.
• 3.81 m - This is uncommon and typically not recommended for standard vehicles.
• 4.72 m - This width exceeds typical vehicle dimensions and is impractical.

The recommended maximum width for vehicles is 2.44 m. This specification ensures safe navigation on roads while maintaining sufficient space for other vehicles.

For highway geometric design purposes, the speed used is based on statistical percentiles.

• The 15th percentile speed indicates that 15% of vehicles travel slower than this speed.
• The 50th percentile speed, or median, shows that half of the vehicles are faster and half are slower.
• The 85th percentile speed is often used in design, as it reflects the speed at which 85% of vehicles are travelling at or below. This helps ensure safety and efficiency.
• The 98th percentile speed is less commonly used but represents an even higher threshold of vehicle speeds.

In highway design, using the 85th percentile speed is standard practice as it balances safety and traffic flow.

Traffic volume refers to the total amount of traffic moving through a particular area over a specified period. It is a critical measure in understanding road usage and planning for transportation systems. Here are the key components to consider:

• Measurement: Traffic volume is usually measured in vehicles per hour or per day.
• Factors Influencing Traffic Volume:
  • Time of day (peak and off-peak hours)
  • Weather conditions
  • Road capacity and conditions
  • Events or activities that attract large crowds
• Importance:
  • Helps in traffic management and planning
  • Aids in identifying congestion points
  • Informs infrastructure development and improvements

By analysing traffic volume, authorities can make informed decisions to enhance road safety and efficiency.

The maximum number of vehicles that can be parked in a given space depends on the type of parking configuration used. Here's a brief explanation of each parking configuration and their capacity:

1. Parallel parking: In this configuration, vehicles are parked parallel to the curb or the parking boundary. This type of parking generally takes up the most space per vehicle, and the number of vehicles that can be parked depends on the length of the parking space and the size of the vehicles.

2. 30º angle parking: In this configuration, vehicles are parked at a 30-degree angle to the curb or the parking boundary. This type of parking allows for more vehicles to be parked in a given space compared to parallel parking, as it requires less space per vehicle. However, it still takes up more space than 45º or 90º angle parking.

3. 45º angle parking: In this configuration, vehicles are parked at a 45-degree angle to the curb or the parking boundary. This type of parking allows for even more vehicles to be parked in a given space compared to 30º angle parking, as it requires less space per vehicle. It is a common parking configuration in parking lots and on some streets.

4. 90º angle parking: In this configuration, vehicles are parked perpendicular to the curb or the parking boundary. This type of parking allows for the maximum number of vehicles to be parked in a given space, as it requires the least amount of space per vehicle. It is the most space-efficient parking configuration and is commonly used in parking lots and garages.

In conclusion, the maximum number of vehicles that can be parked in a given space is achieved with 90º angle parking, as it is the most space-efficient configuration. However, the actual number of vehicles that can be parked will depend on the size of the parking area and the size of the vehicles being parked.