Responses of Laterally Loaded Single Piles Subjected to Various Loading Rates in a Poroelastic Soil

Groundwater table has an important role in soil–structure interaction problems. However, analysis of laterally loaded single piles has often been conducted by solely considering the mechanics of the soil skeleton or decoupling the interactive mechanics of the soil skeleton and the fluid flux; in other words, most analyses were performed without taking into consideration the coupling effect between the soil skeleton and the fluid flux. To improve our understanding of the hydromechanical coupling effect on laterally loaded single piles, a series of finite element study on laterally loaded single piles in saturated porous media was conducted. The effect of pile cap geometries, cap widths, cap embedment depths, and pile lengths, on the response of laterally loaded single piles was also studied. The loading condition of the pile was found to have a significant effect on the generation of excess pore-water pressure. The lateral displacement and bending moment computed at the maximum excess pore water pressure, which in turn, is equivalent to an undrained analysis, produced the minimum responses among all the other loading conditions. The effect of pile cap geometries was found to be much less significant than anticipated.

Impact of pile-to-cap fixity on the design and behavior of sensitive structures

This paper presents the results of analytical studies on the connection between piles and pile caps or footings. Two nonlinear finite element analysis software packages were used to investigate the behavior of the connection itself and the impact of connection assumptions on the overall behavior of different sensitive structures such as simple spans with uneven span lengths, segmental box girders with fixed pier tables, and straddle bents with temperature loading. Results show that the behavior of the connection is affected by variables such as pile size, pile embedment length, pile cap concrete strength, interface reinforcement, and distance between the edge of the pile and the edge of the pile cap. The study also demonstrated that significant moment can develop even with shallow pile embedment lengths. The assumed level of fixity between the pile and pile cap was found to significantly influence the behavior of some of the bridges investigated in this study.

A Review on Effect of Pile Stiffness on Seismic Response of Structure

Pile foundations are widely employed for a variety of structures on shaky ground. The importance of seismic design in ensuring the effective operation of a structure under severe seismic loading conditions cannot be overstated. For the analysis of seismic forces on a structure, IS 1893 will be employed. This research entails the choosing of a specific form of building structure. A comparison of buildings with and without pile foundations will be shown. Because of the differences in their properties, the seismic behaviour of the various structures differs. The influence of pile stiffness on the structure's seismic response will be investigated. The rigidity of the piling foundation could have an impact on the structure.With the rise in seismic activity, there may be a need for more efficient pile foundation design to withstand earthquake loads. The major goal of this study is to compare pile stiffness with changes in diameter and zone. Keywords: Pile Foundation, STAAD-Pro, Structure, Stiffness, zone, Pile Cap, Load Estimation, Pile cap, Pattern of Pile.

Evaluasi Kapasitas Tiang Pancang Miring pada Pilar Jembatan Tipe Pile Cap

Dalam pelaksanaan pembangunan Jembatan Utama pada proyek Jalan Tol X mengalami perubahan bentuk struktur berupa terjadinya kemiringan pada tiang pancang P2 yang tidak sesuai DED sebesar 3°. Sehingga dengan adanya perubahan bentuk struktur tersebut dibutuhkan evaluasi terhadap kapasitas tiang P2 serta harus diperhatikan pengaruh terhadap struktur lainnya. Penelitian ini membahas tentang bagaimana kapasitas tiang pancang setelah mengalami kemiringan serta bagaimana penanganan yang tepat apabila kapasitas tiang tidak memadai. Evaluasi kapasitas tiang dilakukan dengan cara pengecekan terhadap kapasitas dimensi, kapasitas tulangan, kapasitas daya dukung pondasi, serta lendutan pada struktur atas P1-P2 dengan menggunakan bantuan software SAP2000. Hasil penelitian menunjukan kapasitas tiang pancang pada P2 tidak memadai, ditandai dengan kurangnya tulangan pada tiang pancang sebanyak 6-D10,7 mm dan kolom P2 sebanyak 9-D10,7 mm. Akibat dari kapasitas tiang pancang yang tidak memadai, menyebabkan koneksi P1-P2 kekurangan tulangan arah memanjang (top). Maka dari itu diperlukan perkuatan dengan tujuan untuk membuat struktur P1-P2 lebih kaku yaitu dengan cara membuat bracing beton dengan panjang 18,78 meter, lebar 33,92 meter dan tebal 0,8 meter serta kebutuhan tulangan memanjang dan tulangan melintang D32-250. Setelah dilakukan perkuatan, kebutuhan luas tulangan perlu untuk kolom P2, tiang pancang P2, dan koneksi P1-P2 semuanya terpenuhi dengan yang sudah terpasang di lapangan.

JUSTIFICATION OF THE STRESS-STRAIN STATE OF THE PILE FOUNDATION USING SOFTWARE COMPLEXES

Purpose. Bridge supports with a high pile caps require more attention when calculating their strength due to the difficult operating conditions of the piles. The purpose of the scientific article is to substantiate the stress-strain state of the pile foundation of the bridge structure using software computing systems SCAD and LIRA-CAD. Methodology. An analysis of software used to automate the design of foundations was conducted. The main parameters of SCAD and LIRA-CAD software packages are yielded. With their help, finite-element models of the pile foundation of the bridge support with a high pile cap were built. The developed models maximally reflect the properties of the soil base and foundation, its pile cap and piles, geometric characteristics and the influence of the finite elements meshing is considered. Calculations were performed in SCAD and LIRA-CAD software packages with monitoring of the calculation process. Findings. During the numerical analysis of the pile foundation of the bridge structure with a high pile cap, vertical displacements, force factors (normal forces and bending moments) in the piles and stresses in the body of the support and piles were determined. Based on these results, an analysis was performed, which is combined with a comparison of the obtained results. Implementation of SCAD and LIRA-CAD software allows to significantly reduce design time, to reduce project costs, to improve the quality and efficiency of investments. Originality. A comparison of the stress-strain state obtained during the numerical analysis of SCAD and LIRA-CAD software, which proved the difference in the approach to modeling in these complexes, was conducted. Practical value. The results of substantiation of the stress-strain state of the pile foundation with the use of software complexes made it possible to verify the design solution of all elements of the foundation of the bridge structure with a high pile cap.

Building Structure Analysis With and Without Direct Foundation Modelling using Reinforced Concrete Special Moment Resisting Frame

The modelling of placement upon the seismic resistant structure can be carried out separately or directly. Separated modelling refers to the modelling using fixed joint, while direct modelling is defined as the lower structure directly using spring on soil-foundation interaction. Both modelling have differences in the context of behaviour and reaction of structure that must be adjusted based on SNI 1726:2019 and pile needs. This research analysed the calculation of static bearing capacity of pile and manual calculation of k coefficient by Nakazawa method and a supporting program SAP2000 V14.2.5. The analysis results indicated that under the manual calculation, total pile needs on fixed joint modelling of spun pile in diameter 600 mm class B are 185 piles within pile cap modelling at every point of column, meanwhile using SAP2000 V14.2.5, it is obtained the pile needs of spring modelling are 176 piles within integral pile cap modelling. The structural behaviour and the reaction of both modelling demonstrated the values of drift control, period, mass participation, static dynamic shear force, and force output in the fixed joint modelling were less than spring modelling.

Reinforcement Design and Physical Testing of New and Old Cushion Cap of Existing Bridge

As an important part of bridge structure, pile cap plays an important role in its operation. There is a lack of sufficient research in the design and construction of the existing bridges, especially in the operation process of the river crossing bridge, there will be more security risks, so it is urgent to strengthen the bearing platform. Combined with the general design theory of bridge cap, considering the feasibility of construction and the difficulty of operation, the new and old caps are planted with steel bars to make them bear the common force. Aiming at the problem of insufficient bearing capacity, the cap reinforcement method is proposed, so as to improve the stability of the bridge. The research results can provide reference for similar bridge reinforcement projects in the future.