Lateral Performance of Drilled Shafts due to Combined Lateral and Axial Loading

2013 ◽  
Vol 29 (4) ◽  
pp. 685-693 ◽  
Author(s):  
C. J. Chien ◽  
S. S. Lin ◽  
C. C. Yang ◽  
J. C. Liao
Keyword(s):  
Axial Loading ◽  
Senior Author ◽  
Drilled Shafts ◽  
Lateral Loading ◽  
Bending Moments ◽  
Test Results ◽  
Pile Head ◽  
Head Displacement ◽  
Reverse Circulation ◽  
Load Tests

ABSTRACTThis paper reports the results of a series of full-scale drilled shaft load tests subjected to combined axial and lateral loading and lateral loading only. The tested shafts, 1.4m in diameter, were embedded 37m in sandy silt. All tested shafts were installed using reverse circulation method. The test results indicated, given the same lateral loading, 63% of pile head displacement resulted from combined load corresponded with the case of lateral loading only. The test results were compared to the numerical results of the software LPILE as well as the analytical solutions proposed by the senior author and his co-workers. The analytical results of the pile bending moments along shaft showed better results than that of LPILE.

Innovative Method for Evaluating Drilled Shaft Foundations for St. Croix River Bridge

1998 ◽  
Vol 1633 (1) ◽  
pp. 84-93
Author(s):  
Michael W. O’Neill ◽  
Gary J. Person
Keyword(s):  
Drilled Shafts ◽  
Interface Roughness ◽  
Design Parameters ◽  
Lateral Stiffness ◽  
Test Results ◽  
Side Resistance ◽  
Major River ◽  
Load Tests ◽  
Drilled Shaft Foundations ◽  
A Site

To develop design parameters for axially loaded drilled shafts for the St. Croix River Bridge, a major river crossing at Oak Park Heights, Minnesota, load tests were conducted on half-scale sockets in the primary formation, the Franconia Sandstone, at a site on the west bank of the river. The test results were analyzed by using a procedure that considered dilatancy at the shaft-sandstone interface using the known normal, lateral stiffness of the rock, and several candidate interface roughness patterns. The normal stiffness was measured by splitting a short socket vertically with an Osterberg load cell, within the Franconia formation. The interface roughness patterns were varied until the load-deformation behavior of the axial socket test was matched. The production shafts will have larger diameters and will penetrate the formation to a shallower depth than the axial test socket. The lateral stiffness therefore was scaled to account for these effects, and the analytical method was used to determine values of side resistance that should be used for designing the production shafts.

Prediction, Testing, and Analysis of a 50 m Long Pile in Soft Marine Clay

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Bengt Fellenius
Keyword(s):  
Peak Load ◽  
Pile Head ◽  
Marine Clay ◽  
Loading Test ◽  
Head Displacement ◽  
Floating Pile ◽  
Peak Loads ◽  
Static Loading Test ◽  
Beta Coefficient ◽  
Load Movement

On April 4, 2018, 209 days after driving, a static loading test was performed on a 50 m long, strain-gage instrumented, square 275-mm diameter, precast, shaft-bearing (“floating”) pile in Göteborg, Sweden. The soil profile consisted of a 90 m thick, soft, postglacial, marine clay. The groundwater table was at about 1.0 m depth. The undrained shear strength was about 20 kPa at 10 m depth and increased linearly to about 80 kPa at 55m depth. The load-distribution at the peak load correlated to an average effective stress beta-coefficient of 0.19 along the pile or, alternatively, a unit shaft shear resistance of 15 kPa at 10 m depth increasing to about 65 kPa at 50 m depth, indicating an α-coefficient of about 0.80. Prior to the test, geotechnical engineers around the world were invited to predict the load-movement curve to be established in the test—22 predictions from 10 countries were received. The predictions of pile stiffness, and pile head displacement showed considerable scatter, however. Predicted peak loads ranged from 65% to 200% of the actual 1,800-kN peak-load, and 35% to 300% of the load at 22-mm movement.

Research on Static Load Tests of Damaged Bridge Strengthened with Pre-Stressed HFRP

2014 ◽  
Vol 1079-1080 ◽  
pp. 258-265
Author(s):  
Chen Ning Cai ◽  
Shan He ◽  
Li Na Liu ◽  
Shi Kun Ou
Keyword(s):  
Static Load ◽  
Flexural Rigidity ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Structural Members ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Load Tests

Thispaper presents an experimental study to strengthen an existing bridge usingpre-stressed carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer(GFRP) materials. The method using pre-stressed hybrid fiber reinforced polymer(HFRP) to strengthened structural members is an emerging pre-stressed strengtheningtechnology. In this study, experimental data selected from result of staticloading test conducted to hollow slabs with CFRP/GFRP has been compared with specimenswithout strengthening. Test results showed that the strengthening methoddeveloped in this study could effectively reduce the stress in hollow slab,improving the flexural rigidity and inhibiting the concrete from fracture.

Local buckling capacity of C-shaped cold-formed steel sections with punched webs

1984 ◽  
Vol 11 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert Loov
Keyword(s):  
Local Buckling ◽  
Effective Width ◽  
Test Results ◽  
Average Yield ◽  
Steel Sections ◽  
Load Tests ◽  
Cold Formed Steel ◽  
Stub Column ◽  
Best Fit ◽  
The Web

Load tests were carried out on 36 stub column samples of cold-formed steel studs having 38.1 mm wide × 44.5 mm long holes punched through their webs, steel thicknesses of 1.21–2.01 mm, and overall section depths of 63–204 mm. Based on these tests a best-fit equation for the effective width of the unstiffened portion of the web beside the holes has been developed. Suggested design equations have been proposed. The test results support the present equation for the average yield stress [Formula: see text] in Canadian Standards Association Standard S136-1974 but the present code equations for unstiffened plates are unduly conservative when applied to the design of the web adjacent to openings of the size considered.

scholarly journals Cyclic behavior of GFRP strengthened infilled RC frames with low and normal strength concrete

2019 ◽  
Vol 26 (1) ◽  
pp. 30-42 ◽  
Author(s):  
Mehmet Emin Arslan ◽  
Ahmet Durmuş ◽  
Metin Hüsem
Keyword(s):  
Lateral Loading ◽  
Cyclic Behavior ◽  
Test Results ◽  
Normal Strength Concrete ◽  
Strength Concrete ◽  
Rc Frames ◽  
Load Carrying ◽  
Concrete Blocks ◽  
Normal Strength ◽  
Infilled Rc Frames

AbstractThis paper presents the experimental behavior of plane, non-strengthened and glass fiber reinforced polymer (GFRP) strengthened infilled reinforced concrete (RC) frames with low strength concrete (LSC) and normal strength concrete (NSC) under lateral reversed cyclic loading. For this purpose, eight full-scale, one-bay, one-storey plane and infilled (brick and aerated concrete blocks which are commonly used in RC construction) RC frames with LSC and NSC were produced and in-plane lateral loading tests were carried out. Test results indicate that infill walls considerably change the behavior of frames by increasing rigidity and load carrying capacity. By contrast, GFRP fabric used for strengthening of infilled RC frames improves ductility, load carrying and energy dissipation capacity of infilled frames with LSC and NSC as well. After all the test results were evaluated together, a GFRP strengthened brick infilled frame demonstrated the best performance under cyclic lateral loading.

Influence of loading rate on the capacity of a model pile in clay

1995 ◽  
Vol 32 (2) ◽  
pp. 364-368 ◽  
Author(s):  
Robert G. Horvath
Keyword(s):  
Loading Rate ◽  
Axial Loading ◽  
Displacement Transducer ◽  
Test Methods ◽  
Point Load ◽  
Test Results ◽  
Loading Test ◽  
Normal Loading ◽  
Model Pile ◽  
Rate Of Loading

Loading tests were carried out on a model pile embedded in clay to examine the influence of rate of loading on the capacity of the pile. The pile was loaded to failure using constant rate of penetration (CRP), quick maintained loading (QML), and quick continuous loading (QCL) methods of loading. The QCL test models the Statnamic loading test, which has been recently developed in Canada. The CRP tests were used as a reference, and the results were normalized using the CRP test results. The durations of the QML and QCL tests varied from approximately 0.1 s to 17 min, which are significantly faster than normal loading rates. Applied loads and point load were measured using load cells, and top displacement was measured using a displacement transducer. The test results showed an increase in pile capacity with increased rate of loading. Damping was found to be significant for the QCL tests (duration = 0.1 s) and negligible for the QML tests (duration ≥ 10 s). Correcting the results of the QCL tests for damping, using the equilibrium point method developed for Statnamic testing, greatly improved the correlation of the QCL and QML test results. Key words : model piles, axial loading, loading rate, clay, laboratory study, test methods.

Reduction of pile head displacement for restrained-head single pile

2009 ◽  
Vol 13 (3) ◽  
pp. 143-152 ◽  
Author(s):  
Jinoh Won ◽  
Fred H. Kulhawy
Keyword(s):  
Single Pile ◽  
Pile Head ◽  
Head Displacement

scholarly journals Experimental Study on the Temperature Distribution and Residual Strength of Fire-damaged RC Columns Depending on Heated Areas

2020 ◽  
Vol 20 (3) ◽  
pp. 75-80
Author(s):  
Eunmi Ryu ◽  
Heesun Kim ◽  
Yeongsoo Shin
Keyword(s):  
Temperature Distribution ◽  
Residual Strength ◽  
Axial Loading ◽  
Concrete Columns ◽  
Structural Performance ◽  
Test Results ◽  
Floor Plan ◽  
Heated Area ◽  
Actual Fire ◽  
Asymmetric Heating

Most of the columns in actual fire conditions are heated on partial faces rather than all four sides due to the floor plan, which results in asymmetric behaviors of columns. The asymmetric behaviors of fire-damaged columns may cause more vulnerability to the structural performance. In this study, temperature distribution and residual strength of reinforced concrete columns exposed to fire were investigated according to various heated areas. To achieve the objective, columns were heated for 2 h according to ISO-834 standard time-temperature curve and subsequently tested under the axial loading after a week. The test results show that the residual strength of the fire-damaged columns decreased as the heated area increased, and the residual strength reduced additionally due to asymmetric heating.

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