Concept explainers
Calculate the consolidation settlement under the center of mat foundation.
</TO-DETERMINE>
The consolidation settlement under the center of mat foundation is
Given information:
The length of the foundation is
The width of the foundation is
The depth of the foundation
The load value Q is
The preconsolidation pressure
The depth values are
Calculation:
Find the consolidation settlement at the center of the foundation using the relation.
Find the stress
Height of clay
Find the net load per unit area using the relation.
Find the average stress increase in the clay layer below the corner of each rectangular area.
For
Refer to Figure 6.11, “Influence factor
Take the influence factor
For
Refer to Figure 6.11, “Influence factor
Take the influence factor
Find the consolidation settlement at the center of the foundation using the relation.
Therefore, the consolidation settlement under the center of mat foundation is
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
EBK PRINCIPLES OF FOUNDATION ENGINEERIN
- It is stated that the clay layer shown in the figure is OVER CONSOLIDATED clay. The pre-consolidation pressure op' 110 kN. Calculate the consolidation settlement that will occur in the clay layer due to the load of 2500 kN. = 2 Sand 2 Sand 5m Clay Rock 8=2500 kN BxL=1.5mx18m X₁ = 18₁1 kN/m²³ --P6WL Ys=19.6 kN/m³ Ys=20.8 kN/m²³ lo = 0,62 Cc = 0.107 Cs 0.009arrow_forwardThe plan of a flexiblerectangular loaded area is shown with a uniformly distributed load q =100 KN/m2. Determine the increasein the vertical stress (A6z) at Z= 2.0 meters bel ow (a) Point A = (b) Point B= (c) Point C= 4 m 1.6 m- 2 m 0.8 m q = 100 kN/m? C 1.2 m-arrow_forwardA square column foundation with base of 1.40 m is shown in the figure. It carries an axial load of 468 kN and has its bottom. resting on the ground water table located h1 = 1.4 m. below the ground surface. h2 = 0.8 m and h3 = 2.4 m. Compute the settlement of the clay layer in millimeter caused by primary consolidation if the preconsolidation pressure of the clay is 98 KPa. |P * h1 3 h3 + 1.1.1 ECCE ELLET ELEEEEE - Dry Sand Wet Sand Clay ELI ELI LELLFIEarrow_forward
- Given the figure is the soil layer of a project site. The proposed building will exert a net stress of 12 Newtons per square cm. 4 m y=17.6 kN/m³ 11.2 m L'=10.4 kN/m³ w=40% LL=40% 8.2 m Xa=27.3 kN/m³ a) Determine the buoyant unit weight of the clay. [ Select ] b) Determine the vertical effective stress at the midheight of the clay layer. [ Select ] c) Determine the average settlement of the normally consolidated clay layer. [ Select ] Soft Clay Fine Sandarrow_forward8.4 A rectangular foundation is shown in Figure P8.2, given B= 2 m, L=4m q=240 kN/m², H=6m, and D; =2 m. (a) Assuming E = 3800KN/m², calculate the average elastic settlement. Use Eq. (8.24). (b) If the clay is normally consolidated, calculate the consolidation settlement. Use Eq. (8.35) and yat = 17.5 kN/m², C¸ = 0.12, and e, = 1.1.arrow_forwardRefer to Figure, q1 = 90 kN/m; q2 = 325 %3D %3D kN/m; x1 = 4 m; x2 2.5 m; z = 3 m. the vertical stress increase, at point A is nearly (KN/m2) Line load = 91 Line load = 42 Ao 28.6 O 18.6 O 24.6 Oarrow_forward
- * 3 m b. Is the clay overconsolidated? c. What would be the consolidation settlement beneath the center of the mat? 6m A 15 m X 20 m mat foundation shown in Figure P10.7 car- ries a building load of 36 MN and is placed at 3.0 m depth below the ground level. 5 m For the clay layer, the consolidation tests show that the preconsolidation pressure at the middle of the clay layer is 210 kN/m². a. Find the net applied pressure on the underlying ground. Q Sand Clay y = 16.5 kN/m³ Ysat 19.0 kN/m³ e = 0.82 Ce=0.35 and C, = 0.06 =arrow_forwardA soil profile consists of two layers of soil with clay layer underlying the sand layer. The sand layer has a unit weight of 20 kN/m^3 having a thickness of 4 m. and the unit weight of the 2.5m layer of clay is 18 kN/m^3. Compression index of the clay is 0.22 with a void ratio of 1.30. Compute the effective stress (kPa) at the mid height of clay. Calculate the final settlement of the clay layer (mm) due to an increase of pressure of 30 kPa at the mid-height of the clay. Calculate the settlement (mm) when the water table rises to the ground surface.arrow_forward8.4 A rectangular foundation is shown in Figure P8.2, given B=2m, L=4m q = 240 kN/m², H = 6m, and D; = 2 m. (a) Assuming E = 3800KN/m², calculate the average elastic settlement. Use Eq. (8.24). (b) If the clay is normally consolidated, calculate the consolidation settlement. Use Eq. (8.35) and y,t = 17.5 kN/m’, C, = 0.12, and e, = 1.1. %3D G.W.T. D,=2 m = 240 kN/m² Clay e. = .IO H= 6 m 1. Rock Figure P8.2 S,(average) = µ,M0 qB (v = 0.5) E (8.24) (8.35)arrow_forward
- A circular foundation (D = 6 m) is built on a construction site where the soil profile is shown in Figure 5 below. The circular foundation applies a uniform pressure of 80 kPa to the surface of clay. The properties of the clay are: Specific gravity, G₁ Saturated unit weight at Compression index Ce Recompression index Cr Consolidation coefficient, c Over-consolidation ratio, OCR 10 m 6m Ø Clay Impervious rock Figure 5 2.6 20 kN/m³ 0.25 0.10 2.5 m²/year 1.2 (b) Calculate the stress increase at the center of the clay layer and 1) beneath the foundation center and 2) beneath the edge of the foundation; (c) Calculate the consolidation settlement beneath the center of the foundation due to the stress increase; (d) Determine the settlement at the center of the clay after 1 year of applying the pressure; (e) A 50 mm thick clay sample was taken from the site and consolidated in the oedometer, how long it will take for the clay to reach 90% consolidation?arrow_forwardGiven the figure is the soil layer of a project site. The proposed building will exert a net stress of 12 Newtons per square cm. 4 m y=17.6 kN/m³ X=10.4 kN/m³ 11.2 m W-40% LL=40% 8.2 m X=27.3 kN/m³ a) Determine the buoyant unit weight of the clay. b) Determine the vertical effective stress at the midheight of the clay layer. c) Determine the average settlement of the normally consolidated clay layer. Fine Sand Soft Clayarrow_forwardQ-f Calculate the settlement of the bridge pier shown in Fig. Q-f (page 3) due to primary consolidation of the clay. The bridge load imposes an approximate vertical stress increase at the center of the clay layer of 150 kPa. 9 m 1 m 1 m 12 MN Pier: 3 m x 10 m 3 m 5 m Dense sand e = 0.45 E' = 55 MPa v' = 0.35 $' = 36° Normally consolidated clay eo = 0.85 E' = 15 MPa Sand and gravel Cc = 0.3 (su) f = 40 kPa v' = 0.25, vμ = 0.45 c = 30°arrow_forward
- Principles of Foundation Engineering (MindTap Cou...Civil EngineeringISBN:9781305081550Author:Braja M. DasPublisher:Cengage LearningPrinciples of Foundation Engineering (MindTap Cou...Civil EngineeringISBN:9781337705028Author:Braja M. Das, Nagaratnam SivakuganPublisher:Cengage Learning