A certain column carries a vertical downward load of 448.0 k. It is to be supported on a 3.0-ft deep rectangular footing. Because of a nearby property line, this footing may be no more than 5.0 ft wide. The soil beneath this footing is a silty sand with the following properties: y = 122.4 lb/ft, c'=50.0 lb/ft², p=34.0°. The groundwater table is at a depth of 6.0 ft below the ground surface. Using ASD to compute the footing length required for a factor of safety of 3.0. Solution: 1. Determination of the method: According to the given information, the best suitable method would be Surcharge stress D = pcf. 2. Determination of bearing capacity factors - function of ': a. Ne = b. Nq = c. Ny = 3. Determination of other bearing capacity factors: 3.1 Shape factors: a. Se = + b. Sq= c. Sy = 3.2 Depth factors: k= + H /L; psf /L; /L; mehod.

A certain column carries a vertical downward load of 448.0 k. It is to be supported on a 3.0-ft deep rectangular footing. Because of a nearby property line, this footing may be no more than 5.0 ft wide. The soil beneath this footing is a silty sand with the following properties: y = 122.4 lb/ft, c'=50.0 lb/ft², p=34.0°. The groundwater table is at a depth of 6.0 ft below the ground surface. Using ASD to compute the footing length required for a factor of safety of 3.0. Solution: 1. Determination of the method: According to the given information, the best suitable method would be Surcharge stress D = pcf. 2. Determination of bearing capacity factors - function of ': a. Ne = b. Nq = c. Ny = 3. Determination of other bearing capacity factors: 3.1 Shape factors: a. Se = + b. Sq= c. Sy = 3.2 Depth factors: k= + H /L; psf /L; /L; mehod.

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

See similar textbooks

Related questions

Q: A rectangular footing, with a plan area of 1-4mx2·0m is to be placed 2m below the ground surface.…

A: Given Information:

Q: A 3m x 3m square footing is constructed at a depth of 2m in a 26m deep clay layer with following…

Q: = A proposed building is to be supported on a series of spread footing embedded 36 inches into the…

A: d= 36 inch Cc1+e0=0.12Cr1+e0=0.03s'm= 5000 lb/ft2g=120 lb/ft3GWT= 15 ft below the ground surfaceS=1…

Q: A proposed office building will include a 10 ft x10 ft square, 3 ft deep (the footing height is also…

A: Given data: Building area=10 ft*10 ft Depth of footing=3 ft Unit weight, γdry=115 pcf Frictional…

Q: 0.03, eo A 1.5-m square, 0.5-m deep footing carries a downward service load of 180 kN. It is…

A: Dimension of square footing, B = 1.5 m Depth of footing, Z = 0.5 m Load applied, Q = 180 kN CC =…

Q: a square footing is to be constructed on a uniform thick deposit of clay with a unconfined…

Q: At a site, it is planned that a circular grain silo will be constructed at the ground surface. The…

A: At a site, it is planned that a circular grain silo will be constructed at the ground surface. The…

Q: Footing 1 Footing 2 It depends on the soil properties It depends on the loading

A: Footings are often subjected to eccentric loading due to (1) Moments with or without axial forces;…

Q: A 3 ft square footing is founded at a depth of 2.5 ft on saturated clay and carries an…

A: Given : -Square footing of 3 ft - At a Depth = 2.5 ft -Column load = 65 k -Shear strength = 1500…

Q: A soil profile is provided below. The estimated stresses from a spread footing overlying a 9 meter…

A: Height of clay layer (h) = 9 mCc' = 0.22Cs' = 0.04Pre-consolidation pressure (σp) = 215 kPaEstimated…

Q: 2. A medium dense sand is proposed to support a square foundation having a width and length of 5…

A: Given: A square footing (5ftX5ft) resting on medium dense sand Footing is resting a a…

Q: An interior column for a manufacturing building will be supported on the site’s natural clay soil,…

A: The ultimate bearing capacity for square footing is given by,

Q: 4. A 4m x 8m rectangular footing will be placed on ground surface as shown in the figure below. The…

A: Given Data: The dimension of a rectangular footing is A=4 m×8 m The total load acting on the footing…

Q: the elastic settlement of the footing will be

Q: A. What is the equivalent footing and how it is used in foundation design? B. Briefly explain what…

A: A) What is the equivalent footing and how it is used in foundation design? Equivalent footing is a…

Q: There is a square footing with the following information: • Foundation width (B) = 3 ft • Foundation…

A: In this question, we need to plot a graph for the change in factor of safety for the given 3 soils (…

Q: 3.15 A footing with an embedment of 2 m is embedded in a sand with a unit weight of 125 lb/ft³ and a…

A: GIVEN DATA: Embedment length =2m angle of internal friction ϕ=36∘ unit weight of sand =125…

Q: A 1.4-m wide, 2.5-m long, 0.5-m deep spread footing is underlain by a soil with c' = 10.0 kPa, o' =…

A: 1) For Strap footing best suited method is Terzaghis method.

Q: A 4ft by 4ft spread footing is proposed where the bottom of footing is set 2ft below grade. The…

A: Question is based on the footing which is proposed to design a which bottom of which is set at some…

Q: A combined footing is proposed to support two columns, C1 and C2, with loads equal to 2000 kN and…

A: (i) Soil Bearing Capacity:The bearing capacity of the soil can be calculated using the following…

Q: A spread footing with a dimension of 2.0 m x 2.0 m is embedded in uniform clay at a depth of 1.0 m…

A: The given values are as follows,The spread footing size =2.0m×2.0mVertical downward load=300kNThe…

Q: According to Terzaghi's equation, the bearing capacity of strip footing resting on cohesive soil (C…

A: Cohesion C = 10 kN/m2Nc = 5.7 To Find :The bearing capacity of strip footing ?

Q: A square footing (10' x 10') is located 6' below grade. The lowest corrected N value (blow count) is…

A: The values given in the question are as follows: Width of square footing(B)=10 ft Depth of…

Q: Compute the elastic settlement for a rigid 10 ft by 15 ft footing loaded with 4000 psf uniformly…

Q: A 7 foot-square footing is embedded 3 feet below the ground surface and is supported on a clayey…

A: Given:- The dimension of the square footing = 7 ft The depth of footing below the ground surface = 3…

Q: A plate load test was carried out on a ground having a uniform sand stratum upto sufficient depth.…

A: For plate load test carried out on a ground having a uniform sand stratum uptosufficient depthSize…

Q: 3 ft x 3 ft square footing is to be placed over the following soil profile to support 18kips column…

A: Soil profile below the footing: Depth of the Sand layer = 2 ft Depth of the clay layer = 4 ft The…

Q: It is proposed to pour a footing on soil that has been classified as stiff slay. What would be the…

Concept explainers

Load and resistance factor design

Load and resistance factors design (LRFD), also known as Limit state design (LSD), refers to the design method used in building engineering. A boundary condition is a condition of a structure where it can no longer meet the relevant design requirements. The condition may refer to the load level or other actions on the structure, while the terms refer to the integrity of the structure, suitability for use, durability, or other design requirements. A structure designed for LRFD is limited to keeping track of all possible actions during its design time and is always ready for use, with the appropriate level of reliability in each boundary condition. LRFD-based construction codes clearly define the appropriate levels of reliability in their instructions.

Question

4. Using the proper method to estimate the capacity and load:
a. qult =
/L psf;
+
b. Allowable bearing pressure at the bottom of the footing is qa =
c. Bearing pressure at the bottom of the footing is q =
5. According to ASD method, find the minimum width
Minimum length L =
ft;
b. The resistance factor for footing in clay is
c. Selfweight of the footing is Wf =
d. Thus using LRFD, minimum length L =
For construction, the footing length is L =
6. Repeat the problem using LRFD assuming the factored ultimate vertical locumn load is 560 k and dead load factor for selfweight of the footing is YD=1.2.
a. Nominal downward load capacity Pn =
L psf;
e. For construction, the footing length is L =
=
ft;
L obs;
ft;
+
ft;
+
/L psf;
/L psf;

A certain column carries a vertical downward load of 448.0 k. It is to be supported on a 3.0-ft deep rectangular footing. Because of a nearby property line, this footing may be no more than 5.0 ft wide. The soil beneath this
footing is a silty sand with the following properties: y = 122.4 lb/ft³, c'=50.0 lb/ft², p=34.0°. The groundwater table is at a depth of 6.0 ft below the ground surface. Using ASD to compute the footing length required for a
factor of safety of 3.0.
Solution:
1. Determination of the method:
According to the given information, the best suitable method would be
Surcharge stress OD
y' =
=
b. Sq
2. Determination of bearing capacity factors - function of ':
a. Nc =
b. Nq =
c. Ny
=
3. Determination of other bearing capacity factors:
3.1 Shape factors:
a. Sc =
pcf.
=
a. dc =
c. Sy
3.2 Depth factors:
k =
+
=
+
=
/L;
b. dq
c. dy
3.3 Inclination factors:
All inclination factors =
/L;
psf
/L;
3.4 Surcharge stress at depth D:
a. O'zD
psf;
mehod.

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

SEE SOLUTION Check out a sample Q&A here

Step 1 : Data

VIEW

Step 2: Effective unit weight

VIEW

Step 3: Effective vertical stress & Bearing capacity factors

VIEW

Step 4: Shape factors

VIEW

Step 5: Depth factors

VIEW

Step 6: Other Inclination factors

VIEW

Step 7: Ultimate bearing capacity

VIEW

Step 8: Length of footing (L)

VIEW

Step 9: LRFD method

VIEW

Solution

VIEW

Step by step

Solved in 10 steps with 20 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.

Similar questions

A soil profile is provided below. The estimated stresses from a spread footing overlying a 9 meter thick over-consolidated clay layer are: 180.0 kPa (top of the clay layer) 97.2 kPa (middle of the clay layer) 64.3 kPa (bottom of the clay layer) Estimate the primary settlement (in meters) of the clay layer assuming Cc'= Cc/log (1+eo) = 0.22 and Cs' =Cs/log (1+eo)= 0.04 taken from consolidation curves. Assume the pre-consolidation pressure is 215 kPa. Assume no settlement from the overlying sand Depth o (GS) 1- layer. ニ(7.3 SAND KN/m³ -3 m XSAT = 19.8 ELAY 12m
A square footing 5 ft by 5 ft supported on a sandy stratum is designed to carry a column loading of 250,000 lb. The unit weight of the sands underlying the footing location vary between 120 and 125 pcf. Estimate the foundation settlement to be expected using the subgrade reaction method. (Neglect the weight of the footing.)
A proposed building column will carry a downward maximum unfactored load combinationof 250 k and a service load of 185 k. This column is to be supported on a square footing at adepth of 7 ft in a silty sand with the following engineering properties: g = 119 lb/ft3above the groundwater table and 122 lb/ft3 below, c′ = 0, f′ = 32°, N60 = 30. The groundwater tableis 15 ft below the ground surface. The allowable settlement, da, is 0.75 in. The ASD, factor
A building will have a factored column load of 300 kN. The column is to be supported on a square spread footing underlain by a soil with the follow properties: c' = 5 kPa, o' 35°, y = 18.5 kN/m³. The groundwater table is at a depth of 15 m and the footing will be located 0.5 m below the ground surface. Determine the required footing size if Þ = 0.5. Use Terzaghi's bearing capacity equation for a square footing. Solve for 'B', making sure to use the reduction factor Þ; trial and error is the easiest way to solve for 'B'. Recommend a "reasonable" dimension for construction/design purposes.
Design an isolated rectangular footing: P(dead load) = 225 kN P(live load) = 130 kN Qa = 180 kPa Df = 1.5 m Unit wt. of concrete = 23.5 kN/m^3 Unit wt. of soil =17.2 kN/m^3 Bar diameter = 20 mm f`c = 20.7 MPa fy = 248 MPa Width of footing, B is limited to 2m only Column = 40 cm x 40 cm Assume height of footing = 350 mm (check adequacy, if failed - increase the depth) Use min. cover = 75 mm Determine the following: (a) Effective Soil Bearing Pressure, Qe (b) Footing Dimension, L (c) Ultimate Soil Bearing Pressure, Qu (d) Check for Shear Criteria (Beam Shear) (e) Check for Shear Criteria (Punching Shear) (f) Required Steel Area (Long and Short Direction)
A structural engineer finished a design of a library. They determine that each column will carry 1000 lbs. the soil beneath the footing has the properties: gamma= 130 pcf, c= 75psf, phi= 40 degrees. The groundwater table is of great depth so it’s no concern. Sketch figures. What is the minimum size of the footing for a factor of safety of 3? Case 1: assume square footing Case 2: assume round footing
A proposed office building will include an 8 ft 6 in square, 3 ft deep spread footing that will sup-port a vertical downward service load of 160 k. The soil below this footing is an overconsolidated clay with the following engineering properties: Cc /(1 + e0) = 0.10, Cr/(1 + e0) = 0.022,sm′ = 4,500 lb/ft2and g = 113 lb/ft3 . This soil strata extends to a great depth and the ground-water table is at a depth of 50 ft below the ground surface. Determine the total settlement of this footing.
Need help solving this problem, thanks again