A rectangular footing 2.5 m. wide along the y-axis, 3 m. long along the x-axis, supports a circular pedestal, 0.45 m. in diameter. The horizontal force acting at the top of the pedestal along the x-axis of the footing is 144 kN. The total axial load from the pedestal is 1200 kN. Thickness of the footing is 0.70 m., height of backfill on top of the footing is 1.5 m., depth from the top of pedestal to the base of footing is 2.5 m. Concrete unit weight = 24 kN/m2. Unit weight of soil = 17 kN/m³. a. Compute the safe bearing capacity b. If f'c=21MPa, check the wide beam shear and punching shear.

A rectangular footing 2.5 m. wide along the y-axis, 3 m. long along the x-axis, supports a circular pedestal, 0.45 m. in diameter. The horizontal force acting at the top of the pedestal along the x-axis of the footing is 144 kN. The total axial load from the pedestal is 1200 kN. Thickness of the footing is 0.70 m., height of backfill on top of the footing is 1.5 m., depth from the top of pedestal to the base of footing is 2.5 m. Concrete unit weight = 24 kN/m2. Unit weight of soil = 17 kN/m³. a. Compute the safe bearing capacity b. If f'c=21MPa, check the wide beam shear and punching shear.

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

A 1.80m x 1.20m x 0.4m footing with a column at the center is loaded with a column at the center is loaded with a column load of 750 kN and a moment of 290 kN-m acting about the transverse axis of the footing base. The base of the footing is 1.25m below the ground. Use the unit weight of 24 kN/m^3 for concrete and 18 kN/m^3 for the soil above the footing.Determine the equivalent eccentricity of the load,mm?Maximum net soil pressure under the footing, kPa?Required minimum additional axial load so that the whole footing base is under pressure,kN?
The center of two columns for a framed building A and B are 3 m apart. Column A is supported by a square footing 1.25 m by 1.25 m, the base of which is 2.5 m below the groundlevel. The footing of column B is 1 m by 1 m and its base 1.5 m below ground level. The contact pressure on the clay soil under each footing is 400 kN/m². Assume the bases as point loads; 1) Find the stress increase at a depth 5 m below ground level: a) Vertically below the centres of the columns b) Midway between the columns 2) If the coefficient of compressibility of the clay layer is 0.3x102 m2/kN, estimate the differential settlement between the columns if clay is 5 m thick below column A TUTORIAL 9
A square column 439 mm x 439 mm rests on a square footing. The column supports a dead load of 1,040 kN and a live load of 928 kN. The soil bearing capacity is 326.12 kPa. The base of the footing is 2.16 m below the ground. Assume unit weight of concrete of 24 kN/m³ and unit weight of soil of 16.72 kN/m³. The footing has a thickness of 636 mm and the centroid of the main bars is 100 mm from the bottom of the footing. Calculate the nominal one-way shear stress in MPa.
A square column 369 mm x 369 mm rests on a square footing. The column supports a dead load of 1,289 kN and a live load of 739 kN. The soil bearing capacity is 336[85 kPa. The base of the footing is 1.77 m below the ground. Assume unit weight of concrete of 24 kN/m and unit weight of soil of 17.77 kN/m. The footing has a thickness of 593 mm and the centroid of the main bars is 100 mm from the bottom of the footing. Calculate the nominal punching shear stress in MPa. Note: Present the width (B) in multiples of 100 mm.
A square column 439 mm x 439 mm rests on a square footing. The column supports a dead load of 1,040 kN and a live load of 928 kN. The soil bearing capacity is 326.12 kPa. The base of the footing is 2.16 m below the ground. Assume unit weight of concrete of 24 kN/m and unit weight of soil of 16.72 kN/m. The footing has a thickness of 636 mm and the centroid of the main bars is 100 mm from the bottom of the footing. Calculate the nominal one-way shear stress in MPa. Note: Present the width (B)) in multiples of 100 mm.
A square column 449 mm x 449 mm rests on a square footing. The column supports a dead load of 1,039 kN and a live load of 830 kN. The soil bearing capacity is 254.26 kPa. The base of the footing is 1.57 m below the ground. Assume unit weight of concrete of 24 kN/m3 and unit weight of soil of 16.6 kN/m3. The footing has a thickness of 597 mm and the centroid of the main bars is 100 mm from the bottom of the footing. Use fc’ = 24.4 MPa, fy = 248 MPa. Calculate the number of required number of 16 mm ϕ bars Note: Present the width (B) in multiples of 100 mm.
A column carrying an axial load of 30C0 kN has a base plate 0.75 m x 1 m and transmits its loads to the foundation on an area 4.5 m X 4.5 m. Design the beams of a grillage footing.
7. A reinforced concrete square footing supports a 400mm x 400mm square column carrying a total dead load of 740kN and a total live load of 1120kN. The footing dimension is 3m x 3m and is supported by 9 piles 1m apart on a 3x3 formation. The effective depth of the footing is 700mm. Take f’C = 28MPa for concrete and fy = 415MPa for steel. a. Determine the factored load on each pile. b. Determine the nominal wide beam shear stress to be resisted by the footing. c. Determine the nominal punching shear stress to be resisted by the footing. d. Determine the factored moment to be resisted by the footing.
Three concentrated loads Ql = 255 kips, Q2 = 450 kips and Q3 = 675 kips act in one vertical plane and they are placed in the order Ql-Q2~Q3 Their spacings are 13 ft-10 ft. Determine the vertical pressure at a depth of 5 ft along the center line of footings using Boussinesq's point load formula.
A combined rectangular footing is composed of exterior column 450 mm x 600 mm and interior column 600 mm x 600 mm. The 600 mm face of the exterior column coincides the edge of the footing .The depth of the footing is 1.2 m and the bottom of the footing is 1.8 m below the ground. The exterior column carries a service liveload of 510 kN and a service deadload of 790 kN while the interior column carries a service liveload of 820 kN and a service dead load of 1100 kN. Unit weight of soil is 18 kN/m³. Allowable soil pressure is 290 kPa and an additional surcharge of 4.8 kPa placed on the ground surface. Center to center distance of column is 5.5 m. Effective soil pressure at the bottom of the footing is the allowable soil pressure minus the surcharge, pressure due to soil and pressure due to footing. 1. Which of the following most nearly gives the effective soil pressure? a. 265 kPa b. 271.52 kPa c. 245 kPa d. 255.23 kPa 2. Which of the…
A square footing 2.1 m x 2.1 m x 0.27 m thick supports a rectangular column 350mm x 250 mm at its center. Given that: fy = 420 MPa and f’c = 21 MPa and concrete cover to the centroid of steel reinforcement = 100 mm. Use reduction factor for shear 0.75. Determine the maximum nominal load (kN) the footing can sustain based on one way shear.
A 400 mm wall footing carries a PDL = 200 KN/m and PLL= 180 KN/m and a horizontal dead load of 30KN/m and horizontal live load of 30 KN/m cted to a distance 0.30 m from the center of the footing. The base of the footing is 1.20 m from the base on the footing. The allowable soil pressure is 200 kPa. The unit weight of soil is 16 KN/m and that of concrete is 24 KN/m. Use fc' = 28 MPa and fy = 280 MPa. Find the dimension of the footing and the reinforcements needed.