Design of piled foundations for bridge structures for the realignment of US95 in Sandpoint, Idaho, required a predesign static loading test on an instrumented, 406 mm diameter, closed-toe pipe pile driven to 45 m depth in soft, compressible soil. The soil conditions at the site consist of a 9 m thick sand layer on normally consolidated, compressible, postglacial alluvial deposits to depths estimated to exceed 200 m. Field explorations included soil borings and CPTu soundings advanced to a depth of 80 m. The clay at the site is brittle and strain-softening, requiring special attention and consideration in geotechnical design of structures in the area. Effective stress parameters back-calculated from the static loading test performed 48 days after driving correspond to beta coefficients of about 0.8 in the surficial 9 m thick sand layer and 0.15 at the upper boundary of the clay layer below, reducing to 0.07 in the clay layer at the pile toe, and a pile toe bearing coefficient of 6. The beta coefficients ar...
[1]
Bengt H. Fellenius,et al.
Determining the Resistance Distribution in Piles Part 1. Notes on Shift of No-Load Reading and Residual Load
,
2002
.
[2]
Bengt H. Fellenius,et al.
Tangent Modulus of Piles Determined from Strain Data
,
1989
.
[3]
李幼升,et al.
Ph
,
1989
.
[4]
Bengt H. Fellenius,et al.
From Strain Measurements to Load in an Instrumented Pile
,
2001
.
[5]
Abolfazl Eslami,et al.
Pile capacity by direct CPT and CPTu methods applied to 102 case histories
,
1997
.