In the following example, a rectangular foundation must be designed whose B/L ratio must be equal to 0.5.The ultimate allowable load Qadm that must be transmitted to the ground is 520 KN, using a safety factor of 2.0. Designing with Meyerhoff theory, assume that the soil undergoes a general shear failure process. For this problem, propose values of B and L that meet the B/L ratio until Qadm is found to be equal to 520 kN.

A mat foundation, 15 m x 15 m, is made of reinforced concrete and to be supported by a three-layer soil profile, as shown. The mat is 1 m thick, and the average stress on the surface of the slab assessed from the structural engineering analysis is 75 kPa. (Unit weight of concrete = 23.58 kN/m^3) The 5-m thick sand layer immediately below the mat foundation has been compacted to standard Proctor specifications, most likely to optimum moisture content, which is why its moist density is given. (A) Determine the pre-construction effective stress at Point A (bottom of the clay layer). This is the in situ effective stress (overburden pressure) measured from the ground surface prior to the placement of the mat foundation. (B) Determine the vertical stress increase induced by the mat foundation at Point A using the “Influence Chart,” commonly referred to as the “Spider Web.” (C) Determine the vertical stress increase induced by the mat foundation at Point A using the “Stress Isobars.” (D)…

A continuous foundation on a deposit of sand layer is shown in Figure P5.16 along with the variation of the modulus of elasticity of the soil (Es). Assuming g5 18 kN m3 and C2 for 10 years, calculate the elastic settlement of the foundation using the strain influence factor method.

A 300 mm 450 mm plate was used in carrying out a plate loading test in a sand, during which the plate settled 5 mm under the applied pressure of 250 kN/m2. a. What is the coefficient of subgrade reaction for a 300 mm wide square plate? b. What would be the coefficient of subgrade reaction of a 2 m 3 m foundation?

Solve Problem 7.8 using Eq. (7.29). Ignore the post-construction settlement. 7.8 Solve Problem 7.4 with Eq. (7.20). Ignore the correction factor for creep. For the unit weight of soil, use γ = 115 lb/ft3. 7.4 Figure 7.3 shows a foundation of 10 ft × 6.25 ft resting on a sand deposit. The net load per unit area at the level of the foundation, qo, is 3000 lb/ft2. For the sand, μs = 0.3, Es = 3200 lb/in.2, Df = 2.5 ft, and H = 32 ft. Assume that the foundation is rigid and determine the elastic settlement the foundation would undergo. Use Eqs. (7.4) and (7.12).

From the plate load test (plate dimensions 1 ft × 1 ft) in the field, the coefficient of subgrade reaction of a sandy soil is determined to be 60 lb/in3. What will be the value of the coefficient of subgrade reaction on the same soil for a foundation with dimensions of 20 ft × 20 ft?