Engineering Commons^™

Feasibility Study: Alternatives To Prevent Settlements And Bumps At Bridge Approach, Seunghee Kim, Jongwan Eun, Yusuf Alhowaidi, Daniel Robertson

Nebraska Department of Transportation: Research Reports

This project aims to examine the feasibility of improving the current design practice of the approach slab foundation in Nebraska and the alternative of using geosynthetic reinforcement of soils to prevent the bump issues near the end of bridge approaches via an in-depth numerical simulation study. A large-scale pullout test is also conducted as complementary to provide input parameters for the interaction between the regional soil and selected geosynthetics. Based on the results, it is recommended that the number of grade beam piles could be reduced to 40-50 % of the total number of abutment piles while maintaining the same …

Timber Bridge Pile Splicing With Fiber Reinforced Polymer Wraps, Drew L. Damich

Graduate Theses, Dissertations, and Problem Reports

Timber pile repair using splicing is widely used but little research has been done to determine their strength capacity after repair using this method. Current timber pile splicing mechanisms utilize various steel or wooden components. Fiber Reinforced Polymer (FRP) wraps can be utilized as replacement to conventional materials in splicing of timber piles. This study evaluated the strength capacities of traditional splicing mechanisms in relation to FRP wrap splice mechanisms. Traditional splicing mechanisms consisted of flat steel plate, C-channel steel plate, and wooden plate splices. The FRP wrap splice consisted of unidirectional glass/epoxy composite with three layers of fabric as …

Evaluation And Development Of Cpt Based Pile Design In Nebraska Soils, Alex Silvey

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Cone penetration testing (CPT) is a well established geotechnical subsurface investigation technique commonly used for site characterization and soil classification. The CPT gives real time end resistance, side friction, and pore pressure readings. Axially loaded piles also share these two resistance mechanisms, suggesting the cone can be considered similar to a miniature pile. This study focused on evaluating eight CPT methods prediction of pile bearing capacity. The Nebraska Department of Roads (NDOR) conducts dynamic load tests (PDA) of driven pile to verify pile capacity for bridge foundations. 91 comparisons of CPT logs and PDA data were evaluated. CPT prediction methods …

Investigations On Frp-Concrete Bond, Mostfa Al Azzawi

USF Tampa Graduate Theses and Dissertations

This dissertation presents findings from three separate investigations, a laboratory study and two field studies that evaluated the durability of the Fiber Reinforced Polymer (FRP)-concrete bond. The laboratory study explored the role of porosity on CFRP-concrete bond following immersion in warm water. Two disparate field studies measured residual bond after 20 years outdoor exposure of FRP repairs of full-size masonry walls and after 12 years for partially submerged piles supporting the Friendship Trail Bridge, Tampa Bay.

The ACI 440 code requires the same surface preparation for all externally bonded FRP concrete repairs. This disregards the role of porosity that is …

Lateral Resistance Of Pipe Piles Behind A 20-Foot-Tall Mse Wall With Welded-Wire Reinforcements, Ryan Thomas Budd

Theses and Dissertations

Pile foundations for bridges must often resist lateral loads produced by earthquakes and thermal expansion and contraction of the superstructure. Right-of-way constraints near bridge abutments are leading to an increased use of mechanically stabilized earth (MSE) walls below the abutment. Previous research has shown that lateral pile resistance can be greatly reduced when piles are placed close to MSE walls but design codes do not address this issue. A full-scale MSE wall was constructed and 24 lateral load tests were conducted on pipe, square and H piles spaced at distances of about 2 to 5 pile diameters from the back …

Importance Sampling Based Algorithm For Efficient Reliability Analysis Of Axially Loaded Piles, Haijian Fan, Robert Liang

Robert Y. Liang

In reliability analysis, the crude Monte Carlo method is known to be computationally demanding. To improve computational efficiency, this paper presents an importance sampling based algorithm that can be applied to conduct efficient reliability evaluation for axially loaded piles. The spatial variability of soil properties along the pile length is considered by random field modeling, in which a mean, a variance, and a correlation length are used to statistically characterize a random field. The local averaging subdivision technique is employed to generate random fields. In each realization, the random fields are used as inputs to the well-established load transfer method …

Influence Of Pile Shape On Resistance To Lateral Loading, Guillermo Bustamante

Theses and Dissertations

The lateral resistance of pile foundations has typically been based on the resistance of circular pipe piles. In addition, most instrumented lateral load tests and cases history have involved circular piles. However, piles used in engineering practice may also be non-circular cross-section piles such as square and H piles. Some researchers have theorized that the lateral resistance of square piles will be higher than that of circular piles (Reese and Van Impe, 2001; Briaud et al, 1983; Smith, 1987) for various reasons, but there is not test data to support this claims. To provide basic comparative performance data, lateral load …

Lateral Resistance Of Piles Near Vertical Mse Abutment Walls At Provo Center Street, Kent R. Nelson

Theses and Dissertations

Full scale lateral load tests were performed on four piles located at various distances behind MSE walls. Three of the four test piles were production piles used to support bridges, and the other pile a production pile used as part of the bridge abutment. The objective of the testing was to determine the effect of spacing from the wall on the lateral resistance of the piles and on the force resisted by the MSE reinforcement. Lateral load-displacement curves were developed for pile at various spacing and with various reinforcement ratio (reinforcement length, L divided by wall height, H). The force …

Upper Bound Limit Analysis Of Lateral Pile Capacity, Hongyu Qin, Erwin Oh, Wei Dong Guo, P F. Dai

Faculty of Engineering and Information Sciences - Papers: Part A

The upper bound method of plasticity limit analysis is used to estimate the ultimate capacity of laterally loaded long piles. Based on a generic limiting force (or the ultimate soil resistance per unit length) profile, both freehead and fixed-head piles are considered. The current solutions can be reduced to available solutions for some special cases. Design charts may be constructed to estimate the lateral capacity of piles in terms of plastic moment and the parameters describing the limiting force profile.

Lateral Vibration Of Caisson-Pile Composite Foundation In Layered Soils, Maosong Huang, Rui Zhong, Qing Ren

Faculty of Engineering and Information Sciences - Papers: Part A

The improvement of vibration characteristics of caisson foundation due to the piles added at the bottom is studied. Firstly, dynamic equilibriums for lateral vibration of caisson-pile composite foundation are created through the displacement coordination and internal force equilibrium s at the interface between the two parts of the caisson and piles. Vibration equilibriums for the part of caisson are created by external force balance with the utilization of dynamic Winkler model, and vibration characteristics of the part of piles are defined by the existing literatures. Secondly, the coefficients of dynamic Winkler model in vibration of caisson are studied, and improved …

Finite Element Analysis Of Laterally Loaded Piles In Sloping Ground, Vishwas Sawant, Sanjay Shukla

Research outputs 2012

The available analytical methods of analysis for laterally loaded piles in level ground cannot be directly applied to such piles in sloping ground. With the commercially available software, the simulation of the appropriate field condition is a challenging task, and the results are subjective. Therefore, it becomes essential to understand the process of development of a user-framed numerical formulation, which may be used easily as per the specific site conditions without depending on other indirect methods of analysis as well as on the software. In the present study, a detailed three-dimensional finite element formulation is presented for the analysis of …

Experimental Investigation Of Steel Pipe Pile To Concrete Cap Connections, Ryan S. Eastman

Theses and Dissertations

Piles are often used to resist vertical and lateral loads when shallow foundations are inadequate or uneconomical. A critical part in designing pile foundations is the pile-to-cap connection. When a moment resisting connection is desired, reinforcement is typically used between the pile and the cap. A pile-to-cap connection with sufficient pile embedment depth, however, may provide similar results. One model that is currently used to determine the capacity of a pile-to-cap connection was developed by Marcakis and Mitchell for steel members embedded in concrete. This model considers an embedment mechanism that resists rotation at the connection. Recent testing has shown, …

Use Of Embedded Pile Elements In 3d Modelling Of Piled-Raft Foundations, David Oliveira, Patrick K. Wong

Faculty of Engineering - Papers (Archive)

The use of embedded pile elements provides a convenient approach that may save significant modelling time in the simulation of piled foundations. A back-analysis of an Osterberg-cell (O-Cell) load test on a 45 m long pile is presented to illustrate some of the advantages of using structural embedded elements. Comparisons with other modelling approaches for piled-raft foundations have showed good agreement. Three dimensional effects on shaft friction were also investigated in this paper. The simplified example indicates that, although the ultimate shaft friction developed along piles within a piled raft can be significantly greater than that for a single pile …

Influence Of Material Type, Aggregate Size, And Unconfined Compressive Strength On Water Jetting Of Cidh Pile Anomalies, Joseph Carl Heavin

Master's Theses

Water jetting as a means for removing anomalous materials from cast-in-drilled-hole (CIDH) piles was examined. The primary objective of this research was to establish empirical relationships between different jetting parameters and the removal of commonly occurring anomalous zone materials, including low-strength concrete, slurry mixed concrete, grout, and clay soil. Also investigated was the current standard-of-practice used by water jetting contractors within California. The testing specimens consisted of typical anomalous material with unconfined compressive strengths between 5 and 6,000 psi. The experimental work consisted of water blasting submerged specimens using rotary jets, nozzles, and pumping equipment typically used in construction practice. …

Model Tests On Free-Standing Passive Pile Groups In Sand, Wei-Dong Guo, E. H. Ghee

Faculty of Engineering and Information Sciences - Papers: Part A

A number of tests have been conducted to investigate response of vertically loaded capped pile groups in sand undergoing uniform lateral soil movement. The development of shear force, bending moment and deflection along the piles was measured. Presented in this paper are 4 tests on 2-pile free-standing groups, with a view to establish solutions for predicting the pile response. It was concluded that (1) maximum bending moment Mmax is largely linearly related to the sliding force Tmax in stable and moving layers; (2) The combined impact of pile-cap fixity, soil movement profiles, and axial load may be quantified by a …

A Boundary Element Analysis On The Influence Of Krc And E/D On The Performance Of Cyclically Loaded Single Pile In Clay, Sudip Basack

Faculty of Engineering - Papers (Archive)

The environment prevalent in oceans necessitates the piles supporting offshore structures to be designed against lateral cyclic loading initiated by wave action. Such quasi-static load reversal induces deterioration in the strength and stiffness of the soil-pile system, introducing progressive reduction in the bearing capacity associated with increased settlement of the pile foundation. To understand the effect of lateral cyclic load on axial response of single piles in soft clay, a numerical model was previously developed and validated by the author. Using the methodology, further analysis has been carried out to investigate how the variation in relative pilesoil stiffness and eccentricity …

Passive Earth Pressures On A Pile Cap With A Dense Sand Backfill, Robert Ashall Marsh

Theses and Dissertations

Pile groups are often used to provide support for structures. Capping a pile group further adds to the system's resistance due to the passive earth pressure from surrounding backfill. While ultimate passive earth pressure under static loading conditions can be readily calculated using several different theories, the effects of cyclic and dynamic loading on the passive earth pressure response are less understood. Data derived from the full-scale testing of a pile cap system with a densely compacted sand backfill under static, cyclic, and dynamic loadings was analyzed with particular focus on soil pressures measured directly using pressure plates. Based on …

Liquefaction Mitigation Using Vertical Composite Drains And Liquefaction Induced Downdrag On Piles: Implications For Deep Foundation Design, Spencer R. Strand

Theses and Dissertations

Deep foundations constructed in liquefiable soils require specialized design. The design engineer of such foundations must consider the effects of liquefaction on the foundation and overlying structure, such as excessive settlement, loss of skin friction at the soil-pile interface, and the development of downdrag on the pile. Controlled blasting was employed to liquefy a loose, saturated sand in order to test the liquefaction prevention capabilities of full-scale, vertical composite earthquake (EQ) drains and to investigate the development of downdrag on full-scale test piles. Blasting produced liquefaction at a test site without EQ drains which eventually resulted in 270 mm of …

Statnamic Lateral Loading Testing Of Full-Scale 15 And 9 Group Piles In Clay, Rick Davon Broderick

Theses and Dissertations

Studies of seismic and impact loading on foundation piles is an important and a focused interest in the engineering world today. Because of seismic and other natural events are unpredictable, uncontrollable and potentially unsafe it is a vital study to understand the behavior and relationship structures in motion have on there foundation. Statnamic Loading has become a popular method of studying this relationship in a controlled environment. Two groups of 9 and 15 driven hollow pipe piles were tested in saturated clay at the Salt Lake City Airport in July of 2002. The 9-pile group (3x3 configuration) was separated at …

Numerical Simulation Of Pile Group Behaviour In Liquefying Sloping Ground, Deepa S. Liyanapathirana

Faculty of Engineering - Papers (Archive)

This paper investigates pile group behaviour in liquefying sloping ground. The numerical procedure utilised involves two main steps. First a ground response analysis is carried out using a stress path model to obtain the maximum ground displacements along the pile and the degraded soil modulus over the depth of the soil deposit. Next a dynamic analysis is carried out for a single pile in the group assuming that each pile in the group behaves in the same way during the earthquake loading. The method has been verified using centrifuge data, where soil liquefaction has been observed in laterally spreading sloping …

In-Situ Testing Of A Carbon/Epoxy Isotruss Reinforced Concrete Foundation Pile, Sarah Richardson

Theses and Dissertations

This thesis focuses on the field performance of IsoTruss®-reinforced concrete beam columns for use in driven piles. Experimental investigation included one instrumented carbon/epoxy IsoTruss®-reinforced concrete pile (IRC pile) and one instrumented steel-reinforced concrete pile (SRC pile) which were driven into a clay profile at a test site. These two piles, each 30 ft (9 m) in length and 14 in (36 cm) in diameter, were quasi-statically loaded laterally until failure. Behavior was predicted using three different methods: 1) a commercial finite difference-based computer program called Lpile; 2) a Winkler foundation model; and, 3) a simple analysis based on fundamental mechanics …

Laterial Performance Of Drilled Shaft Considering Nonlinear Soil And Structure Material Behavior, Chao-Kuang Hsueh, San-Shyan Lin, Shuh-Gi Chern

Journal of Marine Science and Technology

In addition to nonlinear soil behavior has been assumed in conventional analytical method, performance of the laterally loaded drilled-shaft is also strongly influenced by possible concrete cracking, steel yielding, and shaft/soil separation and interaction. However, these factors are often neglected in the most of available methods and studied results. The main purpose of this paper is to investigate the importance of the above-mentioned effects on lateral performance of drilled reinforced-concrete shaft. The finite element code, ABAQUS, which is available in the three-dimensional analysis is adopted for taking into account the nonlinearity in shaft and soil materials, pilesoil interaction and nonlinear …

An Analytical Model For Deflection Of Laterally Loaded Piles, Jen-Cheng Liao, San-Shyan Lin

Journal of Marine Science and Technology

Load-deflection responses of laterally loaded piles are often obtained via in-situ lateral pile load tests. Problems of such tests are the difficulties occurring during data interpretation. In an effort to develop an efficient analytical method for analyzing deformation data of lateral loaded piles, an analytical model is proposed based on energy conservation of pile-soil system. The proposed analytical model not only provides a direct solution of the pile deflection function, but also has less need of complicated subsurface soil properties. In this paper, the authors present the theory and analytical model development of the proposed method. Two real cases are …

Transfer Length Of Strands In Prestressed Concrete Piles, Baolin Wan, Kent A. Harries, Michael F. Petrou

Civil and Environmental Engineering Faculty Research and Publications

A top bar effect has been identified in prestressed concrete piles. The effect that this top bar effect has on the development of the prestressing strand is investigated. Strand transfer length is found to be proportional to the observed end slip. While the average transfer length of all strands in a section may satisfy the assumptions inherent in the ACI transfer length equation, due to the top bar effect, top-cast strand transfer lengths are considerably in excess of the ACI-calculated value. The flexural behavior of the pile, accounting for varying transfer lengths through its section, is investigated. Finally, recommendations for …

Top Bar Effects In Prestressed Concrete Piles, Baolin Wan, Michael F. Petrou, Kent A. Harries, Aly A. Hussein

Civil and Environmental Engineering Faculty Research and Publications

The top bar effect in reinforced concrete is a widely recognized phenomenon. Currently, the ACI Building Code prescribes a 30% increase in the development length of top cast reinforcing bars. No such provision is required for strands in prestressed concrete members. In this paper, the top bar effect for prestressing strands is introduced. Parameters affecting top bar phenomena in prestressed concrete piles are identified, and strategies for reducing this effect are presented. Finally, for the first time, the application of a top bar effect factor for prestressed concrete development length calculations, similar to the one applied in reinforced concrete structural …

Lateral Impedance Of Single Piles In Inhomogeneous Soil, George Mylonakis, Demetri Roumbas

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The flexural stiffness and damping (dynamic impedance) of a single vertical pile in an inhomogeneous soil deposit with continuously increasing stiffness with depth, is studied. An analytical formulation based on the Beam-on-Dynamic-Winkler-Foundation (BDWF) model is implemented. The model is used in conjunction with a virtual work approximation and pertinent shape functions for the deflected shape of a long flexible pile, which are analogous to those used in finite-element formulations. Explicit closed-form solutions are derived for: (1) the dynamic pile stiffness; and (2) the damping coefficient at the pile head. Both swaying and rocking vibrations are considered and all associated impedance …

Excessive Strand End Slip In Prestressed Piles, Michael F. Petrou, Baolin Wan, Walter S. Joiner, Constantin G. Trezos, Kent A. Harries

Civil and Environmental Engineering Faculty Research and Publications

This paper presents the results of a research project that investigated excessive strand end slip observed recently in some prestressed piles. From measurements taken in the field, it is apparent that the problem o excessive initial strand slip is independent of pile shape and size. Strand end slip is evident in piles of different manufacturers in different states in the Southeast. Excessive strand end slip was found in both the top and bottom of the cross section of the piles, although the top portion of the cross section generally exhibited much higher initial slip. Several preventive measures can be adopted …

Analysis Of Three-Dimensional Pile Groups, M.T. Liang, Y. Liu

Journal of Marine Science and Technology

A numerical technique is presented in the analysis for loading behavior of general three-dimensional pile groups. The striking characteristics of the pile-group model may include raked pile, different pile sizes, non-uniform pile sections, soil inhomogeneit y, soil nonlinearity, and pile-soil-pile interaction. A typical six-pile group is analyzed and the results are compared with that obtained by four other computer programs that are based on different approaches. The computed solutions are shown to have reasonally good agreement with the measured values.