چکیده : 

Elastic–plastic, closed-form solutions were developed recently by the author, to capture the nonlinear

response of laterally loaded rigid piles. Presented in compact form, the solutions are convenient to use,

and sufficiently accurate despite using only two input parameters of the net limiting force per unit length

pu along the pile, and a subgrade modulus k. Nevertheless, piles may be subjected to limited caprestraints

or loading below ground surface, which alter the response remarkably.

This paper provides explicit expressions for estimating loading capacity of anchored piles and develops

new solutions for lateral piles with cap-rotation by stipulating a constant pu or a linear increasing pu (Gibson

pu) with depth. Lateral loading capacity Ho (at the tip-yield state and yield at rotation point state) and

maximum bending moment Mm (at the tip-yield state) are presented against loading locations, and in

form of the lateral capacity Ho Mo (applied moment) locus. The capacity is consistent with available

solutions for anchored piles, and caissons with either pu profile, allowing a united approach from lateral

piles to anchored piles. The new solutions are also presented in charts to highlight the impact of rotational

stiffness of pile-cap on nonlinear response, offering a united approach for free-head piles through

fixed-head piles.

Several advantages of the solutions are identified against the prevalent p–y curve based approach. To

estimate the key parameter pu, values of the resistance factor Np (=ratio of pile–soil limiting resistance

over the undrained shear strength su) are deduced using the current expressions against available normalised

pile capacity involving the impact of gapping (between pile and soil), pile movement mode, pile

slenderness ratio, inclined loading angle (anchored piles) and batter angles (lateral piles). The Np is characterised

by: (i) An increase from 5.6–8.6 to 10.14–11.6, as gapping is eliminated around lateral piles and

caissons, and from 1.0–6.1 to 2.8–9.8, as translation is converted into rotation mode of footings. (ii) Similar

variations with slenderness ratio between anchors and caissons (without gapping), and among

anchors, caissons and pipelines (with gapping). And (iii) A reduction with loading angles (anchors) resembling

that with batter angles (piles).