Finite Element Modelling of Prestressed Concrete Piles in Soft Soils, Case Study: Northern Jakarta, Indonesia

Jakarta is faced with limited land resources due to its position as the capital city of Indonesia. Therefore, numerous high-rise buildings are being constructed to solve this problem and provide accommodations for a large number of Jakarta residents. Studies have shown that prestressed concrete piles (spun piles) are commonly used as the foundations of high-rise buildings in metropolitan cities across Indonesia, especially in the Northern Jakarta Coastal area, which is predominant with deep soft soils deposit. To further assess and verify the ultimate capacity of the pile, a static loading test was conducted. However, not all results from the field test produced ideal, accurate, precise, and reliable load-settlement curve (until failure) results. Therefore, this study aims to determine the soil properties for the analysis of prestressed concrete spun piles with a diameter of 600 mm in the Northern Jakarta coastal area based on the standard penetration test values (SPT-N). It is a case study of a well-documented static pile load test using the kentledge system. Back analyses were performed by the finite element method to obtain the extrapolated load-settlement curve. Furthermore, the effect of interface strength between pile and soil on the load-settlement curve was also investigated. The results showed that a reduction of interface strength leads to a smaller load–settlement curve. In addition, several geotechnical engineering parameters of soil, such as the undrained shear strength and effective young's modulus, were established using data from an in-situ soil site investigation and empirical correlations with SPT-N.

Development of a Practical Heat of Hydration Model for Concrete Curing for Geotechnical Applications

Thermal integrity profiling (TIP) is a common non-destructive technique to evaluate the quality of construction of piles by analysing the temperature fields due to heat of hydration from freshly cast concrete piles. For this process to be accurate, a reliable concrete heat of hydration model is required. This paper proposes a practical and simple to calibrate four parameter model for the prediction of concrete heat of hydration. This model has been shown to be able to reproduce the evolution of heat of hydration measured in laboratory tests, as well as field measurements of temperature within curing concrete piles, as part of a thermal integrity profiling (TIP) operation performed at a site in London. With the simplicity of the model and the small number of model parameters involved, this model can be easily and quickly calibrated, enabling quick predictions of expected temperatures for subsequent casts using the same concrete mix.

Construction of buildings on bored reinforced concrete piles in the area «Gorokhovoye Pole» in Magadan

В работе рассмотрены проблемы возведения фундаментов на территории строительства «Гороховое поле» в г. Магадане, а также описаны инженерно-геологические условия района. Предложена оптимальная технология строительства с использованием бурообсадных железобетонных свай. Описаны преимущества данного типа фундаментов и возможные рекомендации для дальнейшего строительства на территории «Гороховое поле».

Analysis of Soil Pressure in Indoor Model Test of H-Typed Prestressed Concrete Bank Protection Pile

In order to explore the distribution of soil pressure on the side of the pile and the bending moment of the pile body during the excavation and pile loading stages of the H-shaped prestressed concrete piles, three groups of indoor scaled model tests with prestressed rectangular piles and with or without prestressed H-shaped piles were carried out, and the test results shows that the lateral earth pressure on both sides of the sheet pile has the same trend as the static earth pressure calculation value when it is not excavated, but the measured earth pressure at different depths is always lower than the static earth pressure calculation value; in the excavation stage, the H-shaped prestressed pile lateral soil pressure on the side of the pile excavation is less than that of the rectangular sheet pile and the unprestressed H-typed pile.

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.

Effect of groundwater on the displacements of axially loaded pile in clayey soil

The displacement of a loaded pile could be vertical (axial) or horizontal (lateral); these displacements are sensitive to groundwater presence within the soil mass. This paper presents a theoretical study to investigate vertical and horizontal displacement of piles embedded in a clayey soil for different levels of groundwater under the ground surface. The study was performed using the commercial finite element package PLAXIS-3D. Three diameters of the concrete piles were considered: 0.5, 0.75 and 1 m, and were subjected to 1,000 kN axial load. The effect of 0, 5, 10, 15 and 20 m groundwater along the 20 m pile in length from the ground surface on the vertical and horizontal displacements was investigated. The results indicated that the vertical and horizontal displacements increase when the ground water level increases towards the base of pile. Also, there is a significant increase in the horizontal displacement up to 15 m of groundwater level from ground surface and decreased at levels from 15 to 20 m.

Determination of Piles Bearing Capacity using Empirical Methods and (AllPile 6) Software -Cases studies Portsudan and Khartoum Cities

Different methods have been used to determine the pile bearing capacity such as static equations, dynamic equations, empirical methods (EMs), numerical methods, computer software programs, and the pile static load test, these methods were giving different values for pile bearing capacity. In this paper, three empirical methods (Ems) have been selected (Brinch-Hansen, Chin-Kondner, and Decourt) and (AllPile 6) software (AP) has been applied to determine the capacity load of piles for six cases study of drilled concrete piles with a diameter ranging from 800 mm to 1500mm and embedded length ranged 10.5m to 26m. Four of those six piles are located at Portsudan city near the red seacoast and two piles are located in Khartoum city. The results of the pile bearing capacity (PC) calculations obtained using the above-mentioned different methods were compared with results produced by the pile load test. In all six cases study, the settlement of piles was limited, settlement failure was not reached. The results show that the AllPile 6 (AP) and the three mentioned empirical methods (Ems) gave reasonable piles bearing capacity, the (AP) and (BHM) gave the better result than the CKM and DM. While (DM) gave results similar to results determined using the (CKM). However, it was not preferred to use the (CKM) and (DM), unless the failure settlement has occurred in the pile load test.