Installation load and working capacity of jacked piles: some experiences in China

Parallel Session – Geotechnical IIThe working capacity of jacked piles may be self-proved by the load experienced during installation, since the press-in penetration and the static loading test have similar physical background. The ratio of pile’s ultimate capacity to the final jacking load, defined as the pressure ratio in this study, is an interesting but tricking issue in jack piling design and construction. Focus is paid on how the pressure ratio varies with pile’s slenderness ratio and the condition of surrounding and end-bearing soils. With a primary concern on the concrete piles widely used in China, several empirical correlations used in practice are summarized and examined. A new database, with test piles collected from different parts of China, is then presented in an attempt to seek for an effective way to consider the effect of soil condition. A simple sorting method in terms of fine and coarse soils has the potential to properly consider the different behaviors arising from the pile-equalization stage.published_or_final_versio

Pile Selection Methodology

This project entitled - 'Pile Selection Methodology'. The objective of this project is to establish pile selection methodology for different site characteristics. This manual consists of selection procedures for pile and pile driving equipment. The factors that govern the equipment selection include site investigation report which covers the deep boring and analysis of the test report, types of pile which covers the classification and the selection of pile types. Other factor is the pile driving system including noise, vibration and driving resistance were discussed deeply in this report. Bearing capacity and commercial factors were the aspects that affect the selection. Research, data gathering related to the subject, conceptual study were the methodology for this project. At the end of this project, a guideline was produced to assist the contractors to choose the right equipment for particular site conditions

Análisis bibliométrico de la producción científica de artículos acerca de las tuberías de concreto

El aumento en el número de investigaciones sobre diversos temas ingenieriles, entre ellos el de tuberías en concreto, aunado a la importancia del sector, requieren un análisis detallado del carácter de las investigaciones que se están realizando. Este artículo se enfocó en un análisis bibliométrico a partir de la ecuación de búsqueda “Concrete pipe” en la base de datos Scopus, centrada en títulos de artículos, resumen y palabras clave, incluyendo los diferentes años y autores, enfatizando aquellos correspondiente a las áreas de ingeniería, ciencias de los materiales y ciencias ambientales, procediendo al análisis de 1.256 documentos. Estos artículos se analizaron en los programas Bibliometrix y la herramienta de software Vosviewer. Las investigaciones sobre tuberías de concreto datan del año 1952, siendo un tema de interés en la actualidad, encontrando que el país con mayor producción científica es China, representando el 41,48%, así mismo, las afiliaciones más relevantes corresponden a dos universidades ubicadas en Henan, Nanjing y Shanghái, cuyos estudios están enfocados a los procesos sobre la corrosión de las alcantarillas por diferentes patógenos y otros factores, así como sobre el comportamiento de los pilotes de las tuberías de hormigón de alta resistencia y la resistencia del concreto con diferentes agregados, los avances de las investigación están enfocadas hacia los Métodos de diseño de tuberías de concreto, el recubrimientos para protección y refuerzo de tuberías, la evaluación de estado de tuberías de concreto y los aspectos que inciden en la funcionalidad de las tuberías de concreto, entre otras.Universidad Libre Seccional Pereira -- Facultad de Ingeniería -- Ingeniería CivilThe increase in the number of investigations on various engineering topics, among them that of pipes in particular, coupled with the importance of the sector, require a conscientious analysis of the nature of the investigations that are being carried out, this article focused on a bibliometric analysis to starting from the search equation “Concrete pipe” in the Scopus database, focused on article titles, abstract and keywords, including the different years and authors, emphasizing those corresponding to the areas of engineering, materials science and science environmental issues, proceeding to the analysis of 1,204 documents. These articles were analyzed using the Bibliometrix programs, and the Vosviewer software. Research on concrete pipes dates back to 1952, being a topic of interest today, finding that the country with the highest scientific production is China, representing 41,48%, likewise, the most relevant affiliations correspond to two universities located in Henan, Nanjing and Shanghai, whose studies are focused on the processes on the corrosion of sewers by different pathogens and other factors, as well as on the behavior of the piles of high-strength concrete pipes and the resistance of concrete with different aggregates, the advances of the research They are focused on the methods of design of concrete pipes, coatings for protection and reinforcement of pipes, the evaluation of the condition of concrete pipes and the aspects that affect the functionality of concrete pipes, among others

Prediction of axial capacity of piles driven in non-cohesive soils based on neural networks approach

This paper presents an application of two advanced approaches, Artificial Neural Networks (ANN) and Princi­pal Component Analysis (PCA) in predicting the axial pile capacity. The combination of these two approaches allowed the development of an ANN model that provides more accurate axial capacity predictions. The model makes use of Back-Propagation Multi-Layer Perceptron (BPMLP) with Bayesian Regularization (BR), and it is established through the incorporation of approximately 415 data sets obtained from data published in the literature for a wide range of un-cemented soils and pile configurations. The compiled database includes, respectively 247 and 168 loading tests on large-and low-displacement driven piles. The contributions of the soil above and below pile toe to the pile base resistance are pre-evaluated using separate finite element (FE) analyses. The assessment of the predictive performance of the new method against a number of traditional SPT-based approaches indicates that the developed model has attractive capabili­ties and advantages that render it a promising tool. To facilitate its use, the developed model is translated into simple design equations based on statistical approaches

Numerical Study Of Pile Capacity Considering Installation And Negative Skin Friction Effects

Ph.DDOCTOR OF PHILOSOPH

Update the Pile Design by CPT Software to Incorporate Newly Developed Pile-CPT Methods and Other Design Features

Code LTRC Project Number: 17-2GT SIO Number: DOTLT1000165This study presents the performance evaluation of 21 direct pile-CPT methods for estimating the ultimate load carrying capacity of square precast prestressed concrete (PPC) piles driven into Louisiana soils utilizing the cone penetration test (CPT) data. The investigated methods are: Schmertmann, De Ruiter and Beringen, Bustamante and Gianeselli (LCPC), Philipponnat, Price and Wardle, Zhou, Tumay and Fakhroo, UF (2007), probabilistic, Aoki and De Alencar, Penpile, NGI, ICP, UWA, CPT2000, Fugro, Purdue, German, Eurocode7, ERTC3, and Togliani direct pile-CPT methods. A search was conducted in the DOTD files to identify pile load test reports with CPT soundings adjacent to test piles. A database of 80 pile load tests that were loaded to failure, were identified, collected, and used in analysis. The measured ultimate load carrying capacity for each pile was interpreted from the pile load test using the Davisson and modified Davisson interpretation methods. The ultimate pile capacities estimated from the pile-CPT methods were compared with the measured ultimate pile capacities. In this study, three approaches were adopted to evaluate the performance of pile-CPT methods. In the first approach, three statistical criteria were used: the best fit line of predicted (Qp) versus measured (Qm) capacity, arithmetic mean and standard deviation of Qp\u2044Qm, and the cumulative probability of Qp\u2044Qm. The results of this evaluation showed the following best-performed pile-CPT methods in order: LCPC, ERTC3, Probabilistic, UF, Philipponnat, De Ruiter and Beringen, CPT2000, UWA, and Schmertmann methods. The second approach used to evaluate the 21 pile-CPT methods is the MultiDimensional Unfolding (MDU), which showed similar ranking of top-performed pile-CPT methods. The third approach used for evaluating the pile-CPT methods was based on LRFD reliability analysis in terms of resistance factor and efficiency, and the results of evaluation are consistent with the previous two criteria

Field Instrumentation and Testing to Study Set-up Phenomenon of Driven Piles and Its Implementation in LRFD Design Methodology

This research study investigates the pile set-up phenomenon for clayey soils and develops the models to predict pile set-up resistance at a certain time after the end of driving (EOD). The increase of pile resistance after EOD is known as “pile set-up”. To fulfill this objective, a total number of twelve prestressed concrete (PSC) test piles were driven in different soil conditions of Louisiana. In addition, dynamic load tests (DLT) and static load tests (SLT) were usually performed to verify the axial resistances of piles at specific times after EOD, as well as to quantify the amount of increase in resistance compared to the EOD (i.e., set-up). The focus of this research was to calculate the resistance of individual soil layers along the length of the pile. In order to implement this goal, all the test piles were instrumented with vibrating wire strain gages. Vibrating wire piezometers and pressure cells were also installed in the pile face in order to calculate the dissipation of excess pore water pressure, together with the corresponding increase in effective stress, respectively with time. The Case Pile Wave Analysis Program (CAPWAP) was performed in all the DLT data, in order to calculate the resistance of individual soil layers. Logarithmic set-up parameter “A” of individual soil layers were calculated using the unit side resistance (fs). The set-up parameter “A” was tried to correlate with different soil properties. With the aid of Statistical Analysis Software (SAS), detailed regression analyses were performed to develop models with incorporated soil properties. Five different levels of empirical models were developed in order to estimate the amount of set-up. In addition, one set-up model was developed directly from the in-situ test data (corrected cone tip resistance, qt). Load resistance factor calibration was performed in order to calibrate the set-up factor (ϕset-up). The developed models were implemented to predict the amount of resistance at four different time intervals after EOD. Finally, the statistical parameters of measured resistance to predict resistance were applied to calibrate the set-up factor (ϕset-up) and to incorporate that factor into the LRFD framework

Estimation of the Axial and Lateral Capacity of Driven Piles from the Results of Cone Penetration Test and Finite Element Analysis

Piles play an important role in transportation and bridges. They are used to resist axial and lateral loads transferred to them from structures, earth pressures, incline loads, vehicles, etc. In this study, the capacity of piles for axial and lateral loads is investigated. The ultimate axial capacity of piles can be estimated using different approaches including static pile load tests, dynamic load tests, statnamic load tests, and static analysis based on laboratory tests (effective and total stress approaches) or in-situ tests (SPT, CPT, etc.). For each approach, different researchers have proposed different solutions for different soils and different piles. Mostly, engineers use their engineering judgement based on the available information to estimate the pile’s length and diameter (or width). In this study, different pile-CPT methods were evaluated to estimate the accuracy and precision of them for estimating the axial capacity of the piles. Based on the obtained results, the log-normal distribution of the estimated to measured pile capacity for top-ranked pile-CPT methods was adopted to develop combined pile-CPT methods that optimize the estimation accuracy of axial pile capacity in different soil categories. Also, a model for estimating axial pile capacity was developed based on the results of 10 instrumented piles and 80 piles driven in Louisiana. For analyzing the lateral capacity of the piles, finite element method was used to obtain p-y curves. p-y curves is a simple and accurate approach that considers a nonlinear function for soil reaction with pile displacement. Different parameters for sands and clays were studied to find the effects of each parameter on the p-y curve characteristics. Models were developed for clays and sands that consider these parameters. Using the results from the parametric study, numerical models for the ultimate resistance, initial slope, and characteristic shape function are verified and compared to the existing models

Evaluation of the lateral response of micropiles via full scale load testing

Micropiles are a relatively new deep foundation technology in the United States. As an alternative to driven piles or drilled shafts, micropiles can provide substantial support while minimizing cost, environmental impact, and harmful construction vibrations. In order to implement micropiles for new construction on bridges with unsupported lengths, a better understanding of the performance of micropile constituent materials and the structural performance of single micropiles and micropile groups is required. This research addressed the behavior of micropiles under lateral loads. In this configuration, micropiles would be subjected to lateral loads. Thus, there was a need to evaluate the behavior of micropiles as bridge bent foundations with respect to joints between micropile sections and embedment or plunge in rock. The objectives of this study were to demonstrate the lateral performance of micropiles in single and group configurations, determine the effect of casing plunge into rock on lateral resistance of micropiles, determine the effect of casing joints on the lateral resistance of micropile, determine the behavior of jointed micropile sections, and evaluate the durability of micropile casings and jointed sections. These objectives were investigated using a three pronged approach of numerical modeling, full scale field lateral load tests, and laboratory testing. Sixteen sacrificial micropiles were installed in order to perform six lateral load tests. Rock plunge depths of 1, 2, 5 and 10 feet were investigated. Fourteen of the 16 piles comprised two or three sections. A cap was cast around four of the micropiles to create a bent that was load tested against a group of reaction piles. In addition, nine jointed micropile specimens were fabricated and tested in the laboratory under four- point flexure. Numerical models were developed to predict the behavior of the load tests. Subsequently, the results of the field and lab tests were used to calibrate the model for DOT use. A long term study of the impact of corrosion on micropile sections is submitted for future implementation. The main findings of this study include: a) The casing joint has a large impact on the lateral capacity of micropiles. In cases where the micropiles were sufficiently embedded in rock, rather than yielding there was an abrupt failure at the casing joint. This occurrence was observed in the load tests. b) In this study, two feet of embedment for micropiles was sufficient to carry lateral loads greater than 30 kips. Embedment at 5 and 10 feet produced similar results to 2 feet. One foot of embedment does not appear to be sufficient based upon results of the field tests and numerical models. c) Based on field and laboratory tests, the strength of the micropiles with respect to the joints in bending moment was approximately 115 kips*ft. d) Micropiles of 10.75 in. diameter, 0.50 in. wall thickness carried significant lateral load with little deflection. However, the failure mode is brittle, as the piles tested failed abruptly with little lateral displacement. e) Reduction of the section area at threaded joint by 60% to 70% results in a reasonably accurate model for the behavior of the casing joint using FB- MultiPier computer program

Research Report and Findings: Specifications and Guidelines for Rail Tunnel Design, Construction, Maintenance, and Rehabilitation

Industry needs related to rail tunnel design, construction, maintenance, and rehabilitation were identified by reviewing past tunnel incidents and discussions with multiple transit agencies. Compilation of past tunnel incidents includes available reports published by the National Transportation Safety Board (NTSB) and other U.S. and European agencies. The tunnel structural design section covers geotechnical exploration/investigation, geometrical requirements and clearances, load and load combination, structural material and design considerations, waterproofing, and seismic design. Selection of tunnel type is based on geometrical configurations, ground conditions, type of crossing, and environmental requirements, and ground/structure interaction is important in the design process. Good knowledge of the expected geological conditions is essential. Tunnel structural components should satisfy many limit states: (1) service limit state as restriction on stress, deformation, and crack width under normal service conditions; (2) fatigue and fracture limit state as restriction on stress range; (3) strength limit state to ensure strength and stability; and (4) extreme event limit state to ensure the structural survival of a tunnel during a major earthquake, flood, tsunami, collision, blast, or fire. Special consideration is given to waterproofing systems and seismic design