Geotechnical Engineering Circular No. 9 Design, Analysis, and Testing of Laterally Loaded Deep Foundations that Support Transportation Facilities
Download 6.03 Mb. View original pdf
|
Soldier Rev B
- Navigate this page:
- (ton/ft 2 ) 2 - 4
| Loading Condition Coefficient k s or k c (pci) Average Undrained Shear Strength, C a (ton/ft 2 ) 0.5 - 1 Coefficient k s or k c (pci) Average Undrained Shear Strength, C a (ton/ft 2 ) 1 - 2 Coefficient k s or k c (pci) Average Undrained Shear Strength, C a (ton/ft 2 ) 2 - 4 Static 500 1,000 2,000 Cyclic 200 400 800 6. Calculate y 50 as: 𝑦𝑦 50 = 𝜀𝜀 50 𝐷𝐷 Equation A) ε 50 can be obtained from the results of lab tests or from Table Ab Table A Re presentative values of ε50 for stiff clays (Reese et alb ε 50 (-) Average Undrained Shear Strength, C a (ton/ft 2 ) 0.5 - 1 ε 50 (-) Average Undrained Shear Strength, C a (ton/ft 2 ) 1 - 2 ε 50 (-) Average Undrained Shear Strength, C a (ton/ft 2 ) 2 - 4 0.007 0.005 0.004 7. Construct the first portion of the nonlinear part of the p-y curve using the following 2 nd - degree equation 𝑝𝑝 = Equation A) Where p c is the smaller value calculated from Equations A and A. 223 8. Obtain factor A s to be used into construct the nonlinear part of the p-y curve. Obtain A s from Figure A for the selected normalized depth z/D (note that in Figure A, the variable x coincides with depth z ). 9. If the curves defined by Equations A and A intersect in the deformation range 0 ≤ y ≤ As y 50 , the straight line defined by Equation A is maintained. If these curves do not intersect, Equation A controls the p-y curve and the 2 nd - degree equation is extended toy, while the linear portion is discarded. 10. Establish the second portion of the nonlinear part of the p-y curve as follows 𝑝𝑝 = 𝑝𝑝 𝑐𝑐 �0.5 � 𝑦𝑦 𝑦𝑦 50 � 0.5 − 0.055 � 𝑦𝑦 − 𝐴𝐴 𝑠𝑠 𝑦𝑦 50 𝐴𝐴 𝑠𝑠 𝑦𝑦 50 � 1.25 � Equation A) The equation above defines the portion of the p-y curve in the range A s y 50 ≤ y ≤ 6 A s y 50 11. Establish the next straight line portion of the p-y curve as 𝑝𝑝 = 0.5𝑝𝑝 𝑐𝑐 �6𝐴𝐴 𝑠𝑠 − 0.411𝑝𝑝 𝑐𝑐 − 0.0625 𝑦𝑦 50 𝑝𝑝 𝑐𝑐 (𝑦𝑦 − 6𝐴𝐴 𝑠𝑠 𝑦𝑦 50 ) Equation A) The equation above defines the portion of the p-y curve in the range 6A s y 50 ≤ y ≤ 18 A s y 50 12. Establish the final straight line portion of the p-y curve. 𝑝𝑝 = 0.5𝑝𝑝 𝑐𝑐 �6𝐴𝐴 𝑠𝑠 − 0.411𝑝𝑝 𝑐𝑐 − Equation A) The equation above defines the portion of the p-y curve in the range 18 A s y 50 ≤ y. Cyclic Loading For cyclic loading, follow the steps indicated below to construct the p-y curve. 1. Follow Steps 1 - 6 for the p-y curve for static loading. 2. Obtain factor A c to be used into construct the nonlinear part of the p-y curve. Obtain A c from Figure A for the selected normalized depth z/D (note that in Figure A, the variable x coincides with depth z ). 3. Calculate 𝑦𝑦 𝑝𝑝 = Equation A) 4. Construct the parabolic portion of the p-y curve as follows 𝑝𝑝 = 𝐴𝐴 𝑐𝑐 𝑝𝑝 𝑐𝑐 �1 − � 𝑦𝑦 − 0.45𝑦𝑦 𝑝𝑝 0.45𝑦𝑦 𝑝𝑝 � 2.5 � Equation A) The equation above defines the portion of the p-y curve between the point of intersection of the initial straight line and the curve defined by Equation A and y 0.6 y p . If there is no intersection. Equation A controls. 224 5. Establish the next straight line portion of the p-y curve as follows 𝑝𝑝 = 0.936𝐴𝐴 𝑐𝑐 𝑝𝑝 𝑐𝑐 − 0.085 𝑦𝑦 50 𝑝𝑝 𝑐𝑐 �𝑦𝑦 − 0.6𝑦𝑦 𝑝𝑝 � Equation A) The equation above defines the portion of the p-y curve in the range 0.6y p ≤ y ≤ 1.8y p 6. Establish the final straight line portion of the p-y curve as follows 𝑝𝑝 = Equation A) The equation above defines the portion of the p-y curve in the range 1.8y p < y. Download 6.03 Mb. Share with your friends:
|