Precast Piles Research Articles

Capacity Analysis of Precast Piles Connection with Cast in Situ Pillars

Capacity Analysis of Precast Piles Connection with Cast in Situ Pillars

Liquefaction and Reliquefaction Characteristics of Aeolian Sand Foundation Reinforced by Precast Cement Piles Based on Shaking Table Test

With the continuous development of traffic construction, road engineering inevitably crosses the aeolian sand river valley area. Compared with general sandy soil and silty soil, cohesionless aeolian sand foundation has similar properties with fluid and higher liquefaction potential. Precast cement pile can greatly improve the vertical bearing capacity of foundation, but this paper finds that it also has antiliquefaction effect when it is used to reinforce aeolian sand foundation. In addition, there may be more than one liquefaction of aeolian sand foundation in areas with frequent earthquakes. Therefore, this paper explores the liquefaction and reliquefaction characteristics of aeolian sand foundation reinforced by precast cement piles through shaking table test. The test results show that under the excitation of 0.4 g EL Centro wave: (1) the increase of pore pressure in aeolian sand foundation will have multiple instantaneous peaks, which will promote the surface to float or sink. The phenomenon will be weakened by multiple earthquakes or pile reinforcement. (2) The prefabricated cement pile can improve the liquefaction and reliquefaction resistance of aeolian sand foundation. The effect is the best in the shallow layer of the foundation, which is increased by more than 30%, and the deeper the buried depth, the lower the effect. (3) The antiliquefaction ability of foundation will be improved after strong earthquake, but the dynamic response will be significantly increased in the next earthquake. (4) When the aeolian sand foundation reinforced by precast cement piles is reliquefied, the main frequency of the foundation will migrate to low frequency. The liquefied layer will inhibit the low frequency (2 ~ 15 Hz) energy transfer and promote the high frequency (25~30 Hz) energy transfer. The results provide reference for antiliquefaction design of aeolian sand foundation and improve the application of precast cement pile in liquefied foundation.

Wavelet Analysis for Evaluating the Length of Precast Spliced Piles Using Low Strain Integrity Testing

The difficulties with the application of low strain integrity testing for evaluating the length of driven precast piles of two sections justify the need for new data acquisition and analysis techniques. The standard time domain analysis of the recorded signals may not allow for distinguishing the desired responses from a pile toe and a splice. In this paper, we propose the use of a set of hammers of different weights and tip materials that will provide various sensitivities of the test to a pile splice. To further analyze the collected data, we study the distributions of phase angles obtained using complex continuous wavelet transform. The characteristic phase shifts that distribute from higher to lower frequencies can be interpreted as responses from a pile toe and a splice. To verify the proposed approaches, a series of numerical simulations were performed using the finite element method for the driven pile models with the different properties of a splice zone. Numerical simulation results show that the pile splices are clearly identified when using the shorter input pulses which can be generated by light hammers with a hard head material. The total length of a simulated pile with a 1 mm air gap between sections was undetectable by standard data analysis approaches and was evaluated when analyzing the wavelet phase angle distributions. Numerically validated data acquisition and analysis techniques were applied to field data analysis and allowed us to confidently identify the length of two-section piles grouped with a pile cap.

Study on Flexural Performance of Prestressed Concrete Steel Strand Square Piles with Reinforcement

A new type of precast pile, namely steel strand square piles with reinforcement (PRS), is proposed in present study, which uses steel strand as a prestressed reinforcement and is equipped with hot-rolled reinforcement. Two kinds of full-scale pile specimens with different reinforcement were constructed to study the bending performance by the full-scale tests. The finite element model was also performed to study the differences in bending resistance, deformation capacity, crack resistance, and failure mode because of the reinforcement ratio. The results show that the steel strand in the pile was not pulled off, and the concrete in the compression zone was crushed. The finite element analysis results are close to the results of the full-scale test of the piles, which can simulate the flexural performance of the pile well. The experimental results were closer to the theoretical calculation of the cracking moment. The ultimate bending moment value is about 25% more than the theoretical value. The parametric analysis shows that for the PRS with 0.27% prestressed reinforcement, the best bending performance is achieved with 0.64% non-prestressed reinforcement. For the PRS with 0.64% of non-prestressed reinforcement, the best bending performance is achieved with 0.37% of prestressed reinforcement.

Flexible support of a pile embedded in unsaturated soil under Rayleigh waves

AbstractUnder the action of Rayleigh waves, pile head is easy to rotate with a concrete pile cap, and pure fixed‐head condition is rarely achieved, which is a common phenomenon for it usually occurs on the precast piles with insufficient anchorage. In addition, the propagation characteristics of Rayleigh wave have been changed significantly due to the existence of capillary pressure and the coupling between phases in unsaturated soil, which significantly affects the pile‐soil interaction. In order to study the above problems, a coupled vibration model of unsaturated soil–pile system subjected to Rayleigh waves is established on the basis that the pile cap is equivalent to a rigid mass block. Meanwhile, the soil constitution is simplified to linear‐elastic and small deformations are assumed to occur during the vibration phase of soil–pile system. Then, the horizontal dynamic response of a homogeneous free‐field unsaturated soil caused by propagating Rayleigh waves is obtained by using operator decomposition theory and variable separation method. The dynamic equilibrium equation of a pile is established by using the dynamic Winkler model and the Timoshenko beam theory, and the analytical solutions of the horizontal displacement, rotation angle, bending moment and shear force of pile body are derived according to the boundary conditions of flexible constraint of pile top. Based on the present solutions, the rationality of the proposed model is verified by comparing with the previous research results. Through parametric study, the influence of rotational stiffness and yield bending moment of pile top on the horizontal dynamic characteristics of Rayleigh waves induced pile is investigated in detailed. The analysis results can be utilized for the seismic design of pile foundation under Rayleigh waves.

Flexural Test and Numerical Simulation of a New Combination Splice for Prestressed, Precast Concrete Piles Using High-Strength Steel Strands

Prestressed, precast concrete piles using High-Strength Steel Strands (PPCPs using HSSS) are a new type of precast pile. Compared with prestressed high-strength concrete (PHC) piles, the adoption of ultra-high-strength concrete and HSSS not only improves the load-bearing capacity, but also enhances the ductility of precast piles. The engineering application of PPCPs using HSSS requires not only a high bearing capacity of the pile segments, but also reliable splicing to ensure cooperation between pile segments. Based on the characteristics of strand anchorage plates, this paper proposes a new combination splice using the clamp ring and welding (Combination Splice). The theoretical analysis and design method of this Combination Splice is introduced. This research gives a thorough investigation into the flexural performance of PPCPs using HSSS with the Combination Splice. The flexural tests of PPCPs using HSSS with the Combination Splice were firstly conducted on eight full-scale pile specimens with three different pile diameters and four different steel reinforcement ratios. The flexural performances are evaluated in terms of crack resistance, flexural capacities, crack distribution, as well as strain development. The results indicate that the Combination Splice remain safe and intact when the piles reach the ultimate bending capacity. The ultimate bending moment of tested specimens with the Combination Splice is, on average, 10% larger than that of specimens using a theoretical formula. In light of the experimental data, a finite element analysis (FEA) model has been created to simulate the flexural performance of the piles with the Combination Splice. The FEA results show that the load–displacement curves and crack distribution regions are in good agreement with the experimental findings, which verifies the reliability and accuracy of the FEA model. The parameter analysis investigates the effects of the assembly gap and clamp ring corrosion on the flexural performance of PPCPs using HSSS. The results show that assembly gaps have a greater influence on the flexural capacity and deformation, while the influence of the clamp ring corrosion is negligible, indicating that the Combination Splice has certain advantages in terms of durability.

Study Of Productivity And Costs On The Implementation Method Of Foundation Work Using Precast Concrete Pile As A Substitute To The Use Of Wooden Pile Foundations In Low Rise Building (Housing)

The soil condition in Pontianak City is mostly soft soil and peat soil which causes the low bearing capacity of the soil. Various efforts have been made to increase the bearing capacity of the soil, such as the use of wooden pile (kayu cerucuk). With the limited availability of wooden pile, the use of precast piles is an alternative in increasing the bearing capacity of the soil on the foundations of buildings/housings in Pontianak City. The purpose of this study is to compare the productivity and costs of using a wooden pile foundation measuring 12/15 cm with a length of 9-12 M against the use of a square precast concrete pile foundation measuring 15x15 cm2 with a segment length of 3-4 M at a depth of 12-20 M and a size of 12-20 M. 20x20 cm2 with a segment length of 6 M at a depth of 12-18 M in low-rise buildings in Pontianak City. From the results of the study, it is known that the productivity and average cost of piling per M' in a 2-storey shophouse building with an alternative foundation using 12/15 cm cerucuk piles is 22.3 seconds/m' at a cost of Rp. 17,306.24, precast piles square 15 x 15 cm2 of 111.5 seconds/m' at a cost of Rp. 144,274,439 and precast square piles of 20 x 20 cm2 of 125.7 seconds/m' at a cost of Rp. 291,338,955. In a type 150 house building with an alternative foundation using 12/15 cm wooden piles of 18.05 seconds/m' at a cost of Rp. 17,185.58, precast square piles of 15 x 15 cm2 of 104.67 seconds/m at a cost of Rp. 143,890.04 and 20 x 20 cm2 square precast piles of 94.66 seconds/m' with a cost of Rp. 289,724.234. The cost of foundation work with alternative foundations using precast square piles of 15 x 15 cm2 is the most efficient both from the aspect of driving costs, overall costs and the cost of the unit load carried by the foundation

Study Of Productivity And Costs On The Implementation Method Of Foundation Work Using Precast Concrete Pile As A Substitute To The Use Of Wooden Pile Foundations In Low Rise Building (Housing)

The soil condition in Pontianak City is mostly soft soil and peat soil which causes the low bearing capacity of the soil. Various efforts have been made to increase the bearing capacity of the soil, such as the use of wooden pile (kayu cerucuk). With the limited availability of wooden pile, the use of precast piles is an alternative in increasing the bearing capacity of the soil on the foundations of buildings/housings in Pontianak City. The purpose of this study is to compare the productivity and costs of using a wooden pile foundation measuring 12/15 cm with a length of 9-12 M against the use of a square precast concrete pile foundation measuring 15x15 cm2 with a segment length of 3-4 M at a depth of 12-20 M and a size of 12-20 M. 20x20 cm2 with a segment length of 6 M at a depth of 12-18 M in low-rise buildings in Pontianak City. From the results of the study, it is known that the productivity and average cost of piling per M' in a 2-storey shophouse building with an alternative foundation using 12/15 cm cerucuk piles is 22.3 seconds/m' at a cost of Rp. 17,306.24, precast piles square 15 x 15 cm2 of 111.5 seconds/m' at a cost of Rp. 144,274,439 and precast square piles of 20 x 20 cm2 of 125.7 seconds/m' at a cost of Rp. 291,338,955. In a type 150 house building with an alternative foundation using 12/15 cm wooden piles of 18.05 seconds/m' at a cost of Rp. 17,185.58, precast square piles of 15 x 15 cm2 of 104.67 seconds/m at a cost of Rp. 143,890.04 and 20 x 20 cm2 square precast piles of 94.66 seconds/m' with a cost of Rp. 289,724.234. The cost of foundation work with alternative foundations using precast square piles of 15 x 15 cm2 is the most efficient both from the aspect of driving costs, overall costs and the cost of the unit load carried by the foundation

Full-Scale Axial Load Response of Jetted and Grouted Precast Piles in Cohesionless Soils

Full-Scale Axial Load Response of Jetted and Grouted Precast Piles in Cohesionless Soils

Method for Calculating Vertical Compression Bearing Capacity of the Static Drill Rooted Nodular Pile

The static drill rooted nodular (SDRN) pile is a new kind of composite pile foundation made by inserting a precast nodular pile into the cemented soil. Based on the tests and analysis on the mechanism characteristics of these two kinds of interfaces, which are between the pile and cemented soil, and between the cemented soil and soil, this paper proposes a calculation method for the ultimate vertical bearing capability of the SDRN pile considering two failure modes. When the precast pile and surrounding cemented soil fails as a whole, the diameter of the cemented soil pile is taken to calculate the ultimate shaft resistance, and the shaft resistance of the SDRN pile is about 1.05∼1.10 times that of the bored pile in the same soil layer. When the core precast pile fails in penetration mode, the diameter of the core pile is taken. The pile shaft resistance takes that of displacement piles in the same soil layer. The lower nodular pile shaft resistance should consider the squeezing effect of nodular joints. Besides, the improvement of pile tip resistance due to the expanded cemented soil should also be taken into consideration. The result is the smaller value calculated according to these two failure modes. The ultimate bearing capacity of a SDRN pile calculated by the theoretical method is not only compared with the field test result, but also the simulation result of a 2D model pile built by PLAXIS finite element software. In addition, the finite element simulation is also confirmed to be an effective way to investigate the mechanism characteristics of SDRN piles more thoroughly.

Comparative analysis about carbon emission of precast pile and cast-in-situ pile

Building construction are attaching greater importance to decrease carbon emissions in order to mitigate greenhouse effects. Precast pile foundation and cast-in-situ pile foundation are main types of foundations. This paper calculates carbon emissions from prestressed pipe pile foundation and cast-in-situ pile foundation under the same bearing capacity, as well as the carbon emissions from different rectifications to battered piles. Prestressed concrete pipe pile foundation demonstrates comparatively less carbon emissions than cast-in-situ pile foundation. The latter releases 1.4 times more carbon than the former. In the rectifications of battered piles, prestressed concrete pipe pile foundation has significantly lowered carbon emissions, to as much as one third of other solutions. This paper also reveals that measures to reduce carbon emissions involve two raw materials, concrete and steel. Carbon emissions should be listed as the fourth parameter in the design of foundation on the basis of bearing capacity, settlement and economical cost. Green, low-carbon, regenerable raw materials are to be explored and selected for building industry.

Seismic performance of a structural concrete pile-wharf connection before and after retrofit

A full-scale precast prestressed concrete (PC) pile-wharf specimen with a T-headed dowel bar connection detail was tested under realistic loading and boundary conditions. The testing program introduced several seismic loading protocols, which were determined from nonlinear dynamic analyses of a typical U.S. port structure subjected to ground motions for various hazard levels. Conventional reversed cyclic loading tests were also conducted on the pile-wharf connection, damaged by seismic loading protocols, before and after retrofit. The specimen showed excellent seismic performance in terms of both strength and ductility. It was confirmed that the lateral drift response of such a PC pile-wharf connection is largely governed by a rigid-body rocking mechanism, with spalling in the pile and deck near the joint region appearing to be a main cause of stiffness degradation. This study also considered a section enlargement technique as an efficient retrofitting method of pile-wharf connections in container port structures. The retrofitted pile-wharf connection (with prior seismic damage) showed higher stiffness and improved capacity, but its deformation capacity (ductility) was inevitably limited by previously accumulated damage along the precast pile (where no strengthening was applied).

Numerical Analysis of Precast Pile Cap for Accelerated Construction

Abstract Precast pile caps have been widely used in the accelerated construction of cross-sea bridges in recent years. Precast caps are connected to steel pipe composite piles through shear connect...

Alternative Systems and Materials for Splicing Prestressed-Precast Concrete Piles

The use of piles is a common method for establishing deep foundations for bridges where there is a top layer of weak soil. Among various types of pile and installation methods, driving prestressed-precast concrete piles (PPCP) is a durable and economical option compared with the alternatives. Also, since the method employs pile segments prefabricated in precast plants and delivered to the site for installation, it conforms to the principles of Accelerated Bridge Construction (ABC) and provides a rapid alternative to other methods. However, often because of limitations on shipping and transportation, the length of precast prestressed pile segments that can be delivered to the bridge site has to be reduced. Also, headroom limitations for pile driving may limit the length of pile segments such that establishing adequate resistance may not be achieved with one segment. Therefore, splicing of pile segments has to be performed at the site to produce longer lengths. A study carried out as part of research activities at the Accelerated Bridge Construction University Transportation Center (ABC-UTC) at Florida International University has reviewed various types of available pile splices and attempted to build on the experiences gathered for ABC connections to introduce an alternative configuration for splicing PPCP segments. Accordingly, a variation of grouted bar splice was introduced and designed to provide PPCPs with a time-effective, economical, and labor-friendly method of splicing. The proposed connection is completely new for connecting PPCP segments. Because many of PPCPs are driven in a marine environment, the application of corrosion-resistant material at the splice system is also emphasized. The paper summarizes these investigations. The results of this study show that the newly developed systems can provide the required strength in bending, tension, and compression with smaller sizes and numbers of bars. It also makes the installation faster and easier compared with the current methods.

Empirical Bearing Capacity Formula for Steel Pipe Prebored and Precast Piles Based on Field Tests

Abstract In this study, analysis of real-scale field pile loading test results on 20 fully instrumented steel pipe test piles will be carried out, to propose a modified empirical formula to estimat...

Excess Pore Water Pressure Induced by Installation of Precast Piles in Soft Clay

Abstract Soft marine deposits are widely distributed in the coastal region of China. The marine soft clays have high water content and high sensitivity, which shows high compressibility and low str...

Behavior of a Pile Group Supporting a Precast Pile Cap under Combined Vertical and Lateral Loads

AbstractA half-scale field test was conducted on a pile group installed at a stiff clay site. The pile group consisted of eight steel H-piles, with a battered pile at each corner, and connected to ...

Design of prestressed precast pile splice using glass fiber reinforced polymer (GFRP) dowels

For various reasons including shipping and operation limitations and unforeseen soil conditions, it often happens that splicing of precast-prestressed concrete pile (PPCP) segments has to be performed at the site to achieve longer lengths. Epoxy dowel splice is one of the common systems used for splicing PPCPs. The objective of this study was to investigate the effectiveness of glass fiber reinforced polymer (GFRP) dowel bars proposed as an economic corrosion-resistant option for use in pile splices. Analysis was performed for a standard 18×18 in (457×457 mm) PPCP. Two series of material properties were considered for GFRP in the proposed design, mechanical properties in accordance with the Florida Department of Transportation (FDOT) Specifications and improved mechanical properties (2021) under consideration by ASTM D30 Committee. The results show that among various sizes and configurations, the use of 8 #10 GFRP dowels with arrangement similar to that of standard steel dowel splice provides for an optimum design. As an example, the developed design was compared to FDOT requirements. The proposed configuration of GFRP dowels satisfies the requirement for axial compression and tensile capacities. The nominal pure bending capacity of the proposed design is estimated to be 84% and 93% of the threshold capacity for the existing material and improved material, respectively. The flexural resistance of the splice increases with increasing axial compression on the pile to an extent. The use of improved GFRP material for dowel bars shows noticeable enhancement in the flexural resistance so as the use of larger diameter dowels. Detailed drawings for the proposed design were also developed and are presented in this paper.

COMPARISON BETWEEN THE RESULTS OF THE PILE BEARING CAPACITY ANALYSIS BASED ON EMPIRICAL METHOD AND FINITE ELEMENT METHOD USING THE RESULTS OF DYNAMIC ANALYSIS ON THE FIELD

There are many methods for calculating the bearing capacity of a pile foundation. The problem is finding the most representative method for analysis dynamic load testing (PDA) results in the field. This study only covers the areas of West Surabaya and North Surabaya. The method used to analyse the bearing capacity of the pile foundation in this study is the empirical method, namely the Schmertmann, Meyerhof, and L. Decourt method and the finite element method (FEM.). This research only for calculating the bearing capacity of precast pile foundations. The initial stage of the research was to collect soil survey data in the form of N-SPT boring logs and PDA test results in the area. Then the calculation analysis is carried out using the empirical method and FEM, which will be compared with the PDA results. FEM analysis uses dynamic load with pile-driving modelling, which is similar to PDA testing. After comparison, the researchers find some ratios for each calculation method and results of PDAs in the field of study. This study indicates that the most representative method for PDA results in West Surabaya is the Meyerhof method. For the North Surabaya area, these methods have not shown expected results of PDA results in the field

A 3D analytical model for distributed low strain test and parallel seismic test of pipe piles

In this study, the authors proposed a new dynamic integrity test method of piles, namely, distributed low strain integrity test (DLSITs). The basic idea of DLSITs is that a series of accelerated sensors connected by cables are preinstalled on the steel reinforcement cage of cast-in-place pile or attached on the shaft of precast piles. Compared with the conventional methods (LSITs), the efficient detection depth of the DLSITs can be doubled and its detection accuracy is significantly improved. Accordingly, a coupled 3D analytical model is established for the theoretical analysis of the DLSITs. The developed theoretical model is also applied to investigate the 3D effect of the parallel seismic test (PSTs). A vibration mode analysis is conducted to clarify the forming mechanism of the high frequency interference during the DLSITs and PSTs. The main findings can be drawn as: Both the DLSITs and PSTs suffer obvious high frequency interference arisen from the 3D effect of piles. To reduce this adverse influence, the radius angle between the impact force location and the axial line of receiving sensors is advised to set as 90°.