CE-303 Surveying - Dec 2024 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aThe following staff readings were observed successively with a level, the instrument having been moved after third, sixth and eighth readings. Calculate the R.L of points by H.I method. If first reading was taken with a staff held on $\text{B.M} = 432.384\text{ m}$. The staff reading are, $2.228$, $1.606$, $0.988$, $2.090$, $2.864$, $1.262$, $0.602$, $1.982$, $1.044$, $2.684$.
   How to answer

   • Identify instrument change points after 3rd, 6th, and 8th readings and classify readings into BS, IS, and FS
   • Construct the leveling field book table with columns: Station, BS, IS, FS, HI, RL, and Remarks
   • Calculate Height of Instrument (HI) for each instrument station
   • Calculate Reduced Levels (RL) for each observed point
   • Apply arithmetic check: $\sum \text{BS} - \sum \text{FS} = \text{Last RL} - \text{First RL}$
2. 7 Marks
   bExplain the temporary and permanent adjustments of the theodolite.
   How to answer

   • Definition of temporary adjustments (setting up, centering, leveling up, elimination of parallax by focusing eyepiece and objective)
   • Definition and objective of permanent adjustments (establishing fixed fundamental relationships between axes)
   • List of fundamental lines/axes and their desired relationships (plate level axis, horizontal axis, line of collimation, altitude level axis)
   • Brief overview of procedures to perform permanent adjustments
3. 7 Marks
   aExplain characteristic of contours with neat sketches.
   How to answer

   • Define contour line and contour interval
   • List major characteristics: spacing represents steepness, closed loops denote hills or depressions
   • Crossing rules: contour lines never cross or merge except in overhanging cliff or vertical cliff
   • Ridges and valleys: U-shape or V-shape pointing down/up the slope
   • Neat sketches illustrating hill, depression, cliff, ridge, and valley lines
4. 7 Marks
   bExplain the various types of tapes in detail.
   How to answer

   • Introduction to tapes used in chain surveying
   • Cloth or linen tape: composition, advantages, disadvantages (moisture sensitivity, stretching)
   • Metallic tape: linen reinforced with brass or copper wires, improved durability
   • Steel tape: steel ribbon, higher precision, vulnerability to rust and kinks
   • Invar tape: alloy of nickel (36%) and steel (64%), low coefficient of thermal expansion, used for high-precision base line measurements
5. 7 Marks
   aExplain Aerial photography and it's uses in civil engineering.
   How to answer

   • Definition of aerial photography and basic principles (taking photos of ground from airborne platforms)
   • Types of aerial photographs (vertical, low oblique, high oblique)
   • Applications in route selection (highways, railways, pipelines, transmission lines)
   • Use in urban planning, site investigation, topographical mapping, and watershed management
   • Disaster assessment, environmental monitoring, and GIS integration
6. 7 Marks
   bWhat is sounding in Hydrographic survey? Explain.
   How to answer

   • Definition of sounding (measuring the depth below the water surface relative to a datum)
   • Purpose of sounding (mapping underwater topography, navigation charts, dredging operations)
   • Equipment used (sounding rods, lead lines, fathometer / echo sounder)
   • Methods of locating sounding points from shore or boat (range lines, theodolite angles, sextant angles)
   • Datum reduction for tidal corrections
7. 7 Marks
   aA compound curve, consisting of two simple circular curves of radii $350\text{ m}$ and $500\text{ m}$, is to be laid out between two straights. The angles of intersection between the tangents and the two straights are $25^\circ$ and $55^\circ$. Calculate the various elements of the compound curve.
   How to answer

   • Determine total deflection angle $\Delta = \Delta_1 + \Delta_2 = 25^\circ + 55^\circ = 80^\circ$
   • Calculate component tangent lengths: $t_1 = R_1 \tan(\Delta_1/2)$ and $t_2 = R_2 \tan(\Delta_2/2)$
   • Determine the common tangent $t = t_1 + t_2$
   • Use triangle of tangents to compute main tangent distances $T_1$ and $T_2$
   • Calculate curve lengths $L_1 = \frac{\pi R_1 \Delta_1}{180}$ and $L_2 = \frac{\pi R_2 \Delta_2}{180}$, and total length $L = L_1 + L_2$
8. 7 Marks
   bList out the elements of a simple curve with neat sketches.
   How to answer

   • Draw a neat sketch of a simple circular curve showing straights, tangent points ($T_1, T_2$), point of intersection ($V$), deflection angle ($\Delta$), and radius ($R$)
   • List and define Tangent length ($T = R\tan(\Delta/2)$)
   • List and define Length of curve ($L = R\Delta$ in radians)
   • List and define Long chord ($C = 2R\sin(\Delta/2)$)
   • List and define Apex distance ($E = R(\sec(\Delta/2) - 1)$) and Mid-ordinate ($M = R(1 - \cos(\Delta/2))$)
9. 7 Marks
   aDerive an expression for the horizontal distance of a vertical staff from a tacheometer if the line of sight of the telescope is horizontal.
   How to answer

   • Draw the ray diagram of a tacheometer with horizontal sight pointing to a vertical staff
   • Define parameters: focal length $f$, stadia hair interval $i$, staff intercept $s$, distance from objective to vertical axis $d$, and object distance $u$
   • Apply lens formula $\frac{1}{f} = \frac{1}{u} + \frac{1}{v}$ and relation $u = \frac{f}{i} s$
   • Formulate total horizontal distance $D = u + d = \left(\frac{f}{i}\right) s + (f + d)$
   • State multiplying constant $k = f/i$ (usually 100) and additive constant $c = f+d$ (usually 0 for anallatic lens)
10. 7 Marks
    bDiscuss about the Obstacles in chaining with a neat sketch.
    How to answer

    • Classification of obstacles into three categories: obstacles to chaining only (e.g., river, pond), obstacles to ranging only (e.g., hill), obstacles to both chaining and ranging (e.g., building)
    • Methods to bypass obstacles to chaining using right angle or geometry (similar triangles, Pythagorean method)
    • Methods for obstacles to ranging by reciprocal ranging or random line method
    • Neat sketches illustrating measurement around a pond, across a river, and past a building
11. 7 Marks
    aDifference between Plain and Geodetic surveying along with importance of surveying in civil engineering.
    How to answer

    • Tabulate differences between Plane Surveying (curvature neglected, plumb lines parallel, small areas $< 250\text{ km}^2$) and Geodetic Surveying (curvature considered, plumb lines converge, large areas)
    • State the importance of surveying in civil engineering: planning, designing, estimating, and execution of engineering projects
    • Highlight importance in setting out works, determining topography, boundary demarcation, and structural monitoring
12. 7 Marks
    bTwo straights intersect at angle of $122^\circ$. The maximum allowable speed of the vehicle on the curve is $80\text{ km/hr}$. centrifugal ratio is $1/4$ and the rate of change of radial acceleration is $30\text{ cm/sec}^2$. Calculate the radius of the circular curve and the length of the transition curve.
    How to answer

    • Convert velocity to m/s: $v = 80 \times \frac{5}{18} \approx 22.22\text{ m/s}$
    • Use centrifugal ratio $\frac{v^2}{g R} = \frac{1}{4}$ with $g = 9.81\text{ m/s}^2$ to calculate $R = \frac{4 v^2}{g} \approx 201.35\text{ m}$
    • Convert rate of change of radial acceleration: $C = 30\text{ cm/s}^3 = 0.3\text{ m/s}^3$
    • Calculate length of transition curve using rate of change of acceleration formula: $L = \frac{v^3}{C R}$
    • Substitute values: $L = \frac{(22.22)^3}{0.3 \times 201.35} \approx 181.56\text{ m}$
13. 7 Marks
    aWhat do you mean by Traversing? Describe various methods of traversing.
    How to answer

    • Definition of traversing (connected series of lines whose lengths and directions are measured)
    • Types of traverses: closed traverse (loop, link) and open traverse
    • Methods of traversing: Chain traversing (tie lines)
    • Compass traversing (measuring bearings with prismatic/surveyor compass)
    • Theodolite traversing (measuring horizontal angles: included angles, deflection angles, or direct angles)
    • Plane table traversing
14. 7 Marks
    bWhat are the sources of error in chaining? What precautions would you take to guard against them?
    How to answer

    • Classification of sources of errors: Instrumental (incorrect chain length, kinked links), Personal (bad ranging, careless reading, displaced arrows), Natural (temperature variation, pull, sag, wind)
    • Classification by behavior: Cumulative errors and Compensating errors
    • Precautions to guard against errors: standardizing the tape/chain, careful alignment and ranging, applying tension and temperature corrections, keeping proper pull, avoiding sag
15. 7 Marks
    aExplain the two point problem of plane tabling with a neat sketch.
    How to answer

    • Statement/definition of the two-point problem (locating the instrument station on the sheet using two known ground control points)
    • Need for an auxiliary station to achieve proper orientation
    • Step-by-step procedure: setup at auxiliary station $D$, orienting roughly, sighting known points $A$ and $B$, shifting to true station $C$, sighting back, and solving orientation error
    • Neat sketches illustrating the steps and rays at both auxiliary and main stations
16. 7 Marks
    bThe apex distance of a $3^\circ$ circular curve is $82.45\text{ m}$ determine the deflection angle, tangent length and length of long chord.
    How to answer

    • Calculate radius of curve from degree of curve $D = 3^\circ$: $R = \frac{1718.9}{3} \approx 572.96\text{ m}$ (using standard 30 m chain, $R = 1718.9/3$ or using 20 m arc definition $R = 1145.9/3$)
    • Express apex distance: $E = R [\sec(\Delta/2) - 1] = 82.45\text{ m}$
    • Solve for $\sec(\Delta/2) = 1 + \frac{82.45}{R}$ to find deflection angle $\Delta$
    • Calculate tangent length: $T = R\tan(\Delta/2)$
    • Calculate length of long chord: $L_c = 2R\sin(\Delta/2)$