Interpretation of Lateral Load Test of Batter Pile Group Using High Order Polynomials Curve Fitting

2011 ◽  
Author(s):  
Binay Pathak ◽  
Murad Abu-Farsakh ◽  
Xinbao Yu ◽  
Khalid Alshibli
Keyword(s):  
Curve Fitting ◽  
Pile Group ◽  
Lateral Load ◽  
High Order ◽  
Load Test

Prediction of Lateral Load Response for a Pile Group

1997 ◽  
Vol 1569 (1) ◽  
pp. 36-46 ◽  
Author(s):  
Pedro F. Ruesta ◽  
F. C. Townsend
Keyword(s):  
Test Group ◽  
Pile Group ◽  
Lateral Load ◽  
Load Test ◽  
Pressuremeter Test ◽  
In Situ Test ◽  
Concrete Piles ◽  
Load Response ◽  
Pile Load Test

A full-scale lateral load test of a pile group consisting of 16 (4 by 4) prestressed 76-cm-square concrete piles was conducted at Roosevelt Bridge, Stuart, Florida, during the summer of 1996. Presented are ( a) in situ test results, ( b) various p-y curves from these tests, and ( c) comparisons of various computer predictions (FLPIER, GROUP, and PIGR3D) using p-y curves tempered with results from a single-pile load test. From these comparisons, the best Class A prediction is made for the 16-pile group using FLPIER with nonlinear pile properties; p-y multipliers of 0.8, 0.4, 0.3, and 0.3 for the leading, middle, and trailing two rows, respectively; and dilatometer test—pressuremeter test p-y curves. This prediction suggests that an average load per pile of 280 kN will produce a deflection of 0.1 m (63 kips/pile at a deflection of 3.9 in.) for the test group.

Study of static lateral behavior of battered pile group foundation at I-10 Twin Span Bridge using three-dimensional finite element modeling

2016 ◽  
Vol 53 (6) ◽  
pp. 962-973 ◽  
Author(s):  
Ahmad Souri ◽  
Murad Abu-Farsakh ◽  
George Voyiadjis
Keyword(s):  
Three Dimensional ◽  
Pile Group ◽  
Lateral Load ◽  
Load Test ◽  
Fe Model ◽  
Soil Resistance ◽  
Group Effect ◽  
Dimensional Finite Element ◽  
Lateral Behavior ◽  
Three Dimensional Finite Element

In this study, the static lateral behavior of a battered pile group foundation was investigated using three-dimensional finite element (FE) analysis. The FE model was used to simulate the static lateral load test that was performed during the construction of the I-10 Twin Span Bridge over Lake Pontchartrain, La., in which two adjacent bridge piers were pulled against each other. The pier of interest was supported by 24, 1:6 batter, 34 m long piles in a 6 × 4 row configuration. The FE model of the battered pile group was developed in Abaqus and verified using the results from the field test. The model utilized an advanced constitutive model for concrete, which allowed distinct behavior in tension and compression, and introduced damage to the concrete stiffness. The soil domain comprised of several layers in which the constitutive behavior of clay layers was modeled using the anisotropic modified Cam-clay (AMCC) model, and for sands using the elastic perfectly plastic Drucker–Prager (DP) model. FE results showed good agreement with the results of the lateral load test in terms of lateral deformations and bending moments. The results showed that the middle rows carried a larger share of lateral load than the first and the last rows. The pile group resisted a maximum lateral load of 2494 t at which the piles were damaged within a 6 m zone from the bottom of the pile cap. The edge piles carried larger internal forces and exhibited more damage compared to the inner piles. The soil resistance profiles showed that soil layering influenced the distribution of resistance between the soil layers. A series of p–y curves were extracted from the FE model, and then used to study the influence of the group effect on the soil resistance. The p–y curves showed that the group effect reduced the soil resistance in all rows, with the lowest resistance in the third row. Finally, the p-multipliers were calculated using the extracted p–y curves, and compared to the reported p-multipliers for vertical pile groups.

Effects of dead loads on the lateral response of battered pile groups

2002 ◽  
Vol 39 (3) ◽  
pp. 561-575 ◽  
Author(s):  
L M Zhang ◽  
M C McVay ◽  
S J Han ◽  
P W Lai ◽  
R Gardner
Keyword(s):  
Pile Group ◽  
Lateral Load ◽  
Load Test ◽  
Vertical Load ◽  
Pile Groups ◽  
Dead Load ◽  
Vertical Loading ◽  
Lateral Resistance ◽  
Tension And Compression ◽  
Load Tests

The effects of vertical load on the lateral resistance of single piles were initially reviewed to facilitate the interpretation of the test results of pile groups. Then, 18 different lateral load tests were carried out in the centrifuge on the 3 × 3 and the 4 × 4 fixed-head battered pile groups to investigate the effects of vertical load on the group lateral resistance. Vertical dead loads ranging from approximately 20 to 80% of the vertical ultimate group capacity Puv were applied. Based on these tests, the effects of vertical dead load on the lateral resistance of the battered pile groups are found to depend on pile arrangement, pile inclination, and soil density. The lateral resistances of the 3 × 3 pile groups do not appear to vary considerably with the vertical dead loads in the range of the vertical loads studied. For the 4 × 4 pile groups however, the lateral resistances at vertical loads of approximately 50 and 80% Puv may be 26-29% and even 40% higher than that at the 20% Puv dead load. It may be inferred that designs based on standard lateral load tests with small vertical dead loads would be on the safe side. Three mechanisms for vertical load effects are discussed in terms of axial tension and compression failures, influence of pile inclination, and initial subgrade reaction caused by vertical loading. Preliminary numerical analyses are also performed to simulate the responses of some of the battered pile groups.Key words: pile group, battered pile, lateral resistance, load test, pile-soil interaction, centrifuge test.

Polynomial Moving Fitting Method for Edge Identification

2011 ◽  
Vol 308-310 ◽  
pp. 2560-2564 ◽  
Author(s):  
Xiang Rong Yuan
Keyword(s):  
Edge Detection ◽  
Curve Fitting ◽  
Polynomial Function ◽  
High Order ◽  
Polynomial Fitting ◽  
Fitting Method ◽  
Order Polynomial ◽  
Better Than ◽  
Low Order

A moving fitting method for edge detection is proposed in this work. Polynomial function is used for the curve fitting of the column of pixels near the edge. Proposed method is compared with polynomial fitting method without sub-segment. The comparison shows that even with low order polynomial, the effects of moving fitting are significantly better than that with high order polynomial fitting without sub-segment.

Lateral Load Capacity and Passive Resistance of Full-Scale Pile Group and Cap

2000 ◽  
Vol 1736 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Kyle M. Rollins ◽  
Andrew E. Sparks ◽  
Kris T. Peterson
Keyword(s):  
Load Capacity ◽  
Pile Group ◽  
Lateral Load ◽  
Full Scale ◽  
Dynamic Resistance ◽  
Back Side ◽  
Passive Resistance ◽  
Passive Pressure ◽  
Pile Cap ◽  
Measured Resistance

Static and dynamic (statnamic) lateral load tests were performed on a full-scale 3 × 3 pile group driven in saturated low-plasticity silts and clays. The 324-mm outside diameter steel pipe piles were attached to a reinforced concrete pile cap (2.74 m square in plan and 1.21 m high), which created an essentially fixed-head end constraint. A gravel backfill was compacted in place on the back side of the cap. Lateral resistance was therefore provided by pile-soil-pile interaction as well as by base friction and passive pressure on the cap. In this case, passive resistance contributed about 40 percent of the measured static capacity. The measured resistance was compared with that computed by several techniques. The log-spiral method provided the best agreement with measured resistance. Estimates of passive pressure computed using the Rankine or GROUP p-y curve methods significantly underestimated the resistance, whereas the Coulomb method overestimated resistance. The wall movement required to fully mobilize passive resistance in the dense gravel backfill was approximately 0.06 times the wall height, which is in good agreement with design recommendations. The p-multipliers developed for the free-head pile group provided reasonable estimates of the pile-soil-pile resistance for the fixed-head pile group. Default p-multipliers in the program GROUP led to a 35 percent overestimate of pile capacity. Overall dynamic resistance was typically 100 to 125 percent higher than static; however, dynamic passive pressure resistance was over 200 percent higher than static.

Lateral Load Behavior of Pile Group in Sand

1988 ◽  
Vol 114 (11) ◽  
pp. 1261-1276 ◽  
Author(s):  
Dan A. Brown ◽  
Clark Morrison ◽  
Lymon C. Reese
Keyword(s):  
Pile Group ◽  
Lateral Load ◽  
Load Behavior
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