a. A symmetrical rectangle box section prestressed concrete beam of external width of 300 mm and external depth of 600 mm with a uniform thickness of 40 mm is prestressed with 7 numbers straight steel wires of 7 mm diameter located at a distance of 15 mm from the bottom of the soffit and 5 number of 5mm diameter of the steel wires located at the 575 mm from the bottom of the beam . The wires were initially tensioned on the prestressing bed with an initial prestress of 1500 N/mm2 . The beam is subjected to point load of 48 + 0.2 (54) kN at the center of the beam and a uniformly distributed load of 20 kN/m entire length of the beam with a length of 10 m. Calculate the resultant stresses at the end and mid span section with neat stress distribution diagram. Assume the density of the concrete is 24 kN/m3 . Use BS8110 code

b. In the above problem, how to control the resultant stresses such that they do not exceed 25 N/mm2 at mid span section.

a. An unsymmetrical I section prestressed concrete beam of top flange (350 X 40 mm) in size, bottom flange of (200 X 40 mm), 30mm thickness of web and overall depth of 400 mm is prestressed with 19 numbers straight steel wires of 7 mm diameter located at a distance of 15 mm from the bottom of the soffit and 9 numbers of straight steel wires of 6 mm diameter located at a distance of 15 mm from the top of the beam. The wires were initially tensioned on the prestressing bed with an initial prestress of 1.2 + 0.01 (54) GPa. The length of the beam is 10 m. Calculate the total percentage loss of stress in the wires at top and bottom. Assume the beam is post tensioned beam and all the wires stressed simultaneously by using the following data: Relaxation of steel stress= 4.5% of initial stress -6 Shrinkage strain in concrete for post tensioning = 200 x 10 Creep Coefficient ɸ=1.6 Friction coefficient for wave effect=0.0015 + 0.001 (54) per meter Slip at anchorage= 1.5 mm Modulus of elasticity for steel = 210 GPa Modulus of elasticity for concrete= 35 GPa

b. What are the measures that are suggested to be taken to reduce the losses in prestressed concrete members for the above problem?

prestressed road bridge of span 16.74 m consists of a
concrete slab of 420 mm thick with parallel post-tensioned cables, in each of which the force
at transfer is 440 kN. If the bridge is required to support a uniformly distributed applied load
of 43.37kN/m2
, with tensile stress in the concrete not exceeding
0.85 N/mm2
at any time. Calculate the maximum horizontal spacing of the cables, their
distance from the soffit of the slab at mid-span and their lowest possible position at
supports. Assume 15 % loss of prestress after transfer. Also calculate the number of steel
wires used in each cable with the permissible stress of 1200 N/mm2
for 7 mm diameter steel
wire. Assume the density of the concrete is 24 kN/m3
.

. A symmetrical rectangle box section prestressed concrete beam of external width of 300
mm and external depth of 600 mm with a uniform thickness of 40 mm is prestressed with 7
numbers straight steel wires of 7 mm diameter located at a distance of 15 mm from the bottom
of the soffit and 5 number of 5mm diameter of the steel wires located at the 575 mm from the
bottom of the beam . The wires were initially tensioned on the prestressing bed with an initial
prestress of 1500 N/mm2
. The beam is subjected to point load of 55.4 kN at the center of the beam and a uniformly distributed load of 20 kN/m entire length
of the beam with a length of 10 m. Calculate the resultant stresses at the end and mid span
section with neat stress distribution diagram. Assume the density of the concrete is 24
kN/m3
.

b. In the above problem, how to control the resultant stresses such that they do not exceed
25 N/mm2 at mid span section.

There are two steel I beams in a construction cite. The I beam A has 3" long stringer in the middle of the beam in the center of shear web and the second beam (beam B) has multiple edge cracking (0.1" deep) due to improper rolling process in the same middle area as beam A in both top and bottom flanges. As an engineer discuss which of the discontinuities will be more likely to be considered as a defect? Why?

A retaining wall has a stem height 8.5m and width is 0.5m from top and 1.4 from below. The base is 7.0x1.5m. the toe is 1.8m and the heel is 3.8m. the backfill is inclined by 15^o. Ɣ=18KN/m³ and Φ=25

Find if the given retaining wall is stable against sliding and overturning or not. Ɣ concrete = 24KN/m³. δ = 0.6 ɸ

Q4: Experiments were conducted to determine the safe buckling load on columns with T-section 100 mm × 100 mm × 10 mm with different support conditions. When both ends of the columns are fixed, safe crippling load carried by the column was found to be 60 × 103 N. Suggest the length for other three columns for the same crippling load when the support conditions are changed to one end fixed but the other end free, both the ends hinged and one end fixed but the other end hinged. The cross section of the column is kept constant in all cases, and E = 200 GPa. Take factor of safety = 4. Instead of T section, a hollow column of same material having length 5 m and external diameter of 55 mm when subjected to a compressive load of 60 kN, there was a shortening in the length of the column by 0.120 cm. Suggest a suitable value for the thickness of the column to withstand the safe crippling load when one end of the column is fixed and other end is free?

Please define streamline, streakline, and pathline (illustrations welcome):

Q2: For analyzing a structure, shear force and bending moment diagrams were plotted for a simply supported beam of span 8 m when subjected to a uniformly distributed load of ‘w’ kN/m over a length of 4 m from the left end support, a point load ‘2.4 w’ kN at a distance 6 m from the left end support and another uniformly distributed ‘0.6 w’ kN/m at a distance 2 m from the right end support. It was noted that the magnitude of shear force at distance 4 m from the left end support is equal to (-12.5 kN). Suggest a suitable value for ‘w’ based on the given data. How it will change the reactions at the supports, shear force and bending moment values. By plotting bending moment and shear force diagram for the beam briefly conclude the relationship between the values for shear force and bending moment.

Describe about the fundamentals of facultative ponds

Compute |A|, the determinant of A (note: rounding errors during computation may cause Matlab to return a value like 6.2137e-16 in place of 0; in such cases, write 0 as your answer; though not necessary, you can verify the answer by computing the value of the determinant by hand). State the Matlab function you use to compute the determinants.

Using 7/8 in diameter ASTM A325-N bolts in standard holes and E70 electrodes. Design a bolted flange-plated FR moment connection between a W12×50 beam and a W14×90 column flange (RD = 15 kips; MD = 60 kip-ft) and (RL = 30 kips; ML = 120 kip-ft). For shear plate use three bolts:

(I) Check the beam available flexural strength

(ii) Design single-plate web connection

(iii) Check the connecting elements rupture strength at welds

Sketch the connection.