scholarly journals Improvement of methods for pile foundations design on settlement

Vestnik MGSU ◽  
2021 ◽  
pp. 331-339
Author(s):  
Vladimir S. Utkin ◽  
Leonid A. Sushev ◽  
Sergey A. Solovev

Introduction. The paper describes a new approach for pile foundations design. The system of mechanical impacts is described in a new way for the pile foundation design based on the foundation settlement taking into account the distribution of elastic deformation of the pile material in a soil base. Materials and methods. In contrast to the existing approaches to determining the pile settlement due to elastic deformations of the pile material, all impacts in the form of load from the pile cap, friction forces on the pile lateral surface and the actual reaction at the pile tip are taken into account differentially according to the principle of forces independence. The new design equation is proposed to describe the distribution of friction forces on the lateral surface of the pile. The friction forces in a homogeneous soil of the base are represented as a parabolic distribution function, and not as a linearly increasing one, as established in the standards. Results. As a result, the equation is obtained for a pile settlement design due to the elastic strain of pile material. An example of calculating the pile settlement according to the proposed method and comparing the results with existing methods is given. Negative friction forces from the reaction of the soil under the lower end of the pile increase the value of the elastic deformation of the pile shaft. Conclusions. The refined equation for calculating the elastic component of the pile settlement makes it possible to obtain a lower value of the settlement in comparison with the standard approach by taking into account the influence of friction forces of the soil along the pile lateral surface. The proposed method for pile foundations design based on the settlement can serve as a justification for the reserve of the load-bearing capacity of the pile foundation according to the settlement criterion which will allows obtaining a certain economic effect.

Author(s):  
Mohit Bharat Dange

Abstract: 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.


2021 ◽  
Vol 258 ◽  
pp. 09036
Author(s):  
Vladimir Kocherzhenko ◽  
Lyudmila Suleymanova

The paper discusses the methods of erecting sunk wells and pile foundations, which consist in regulating the frictional forces of soils: lowering along the lateral surface when sinking wells and increasing when erecting pile foundations. The developed method of sinking wells provides for the application of two types of effective antifriction coatings along the lateral surface: along the cutting edge of the structure and above the cutting ledge. At the same time, the coefficients of reducing the friction forces by these coatings for various types of soils have been established, and a method for calculating sunk wells for lowering is proposed, taking into account the use of the developed submerging method. To increase the friction forces on the lateral surface of the driven piles and to increase their bearing capacity, modular piles with a developed lateral surface of the T-section have been developed and introduced. The areas of rational use of these piles are established depending on the types of soils (clay and sandy) and the depth of their penetration.


Author(s):  
M. J. Pender

Methods of assessing, for preliminary design purposes, the stiffness and capacity of pile foundations under seismic forces are presented. Although the main thrust of the paper is to aseismic design the methods are applicable to other forms of dynamic excitation of pile foundations. Emphasis is placed on expressions for pile stiffness and capacity in the form of simple formulae that can be incorporated into spreadsheet or similar types of software. The use of the equations is illustrated with a number of worked examples. Where possible the methods are justified by data from field testing of foundations at prototype scale.


2021 ◽  
Vol 820 (1) ◽  
pp. 012019
Author(s):  
Qingwen Guo ◽  
Baohua Guo ◽  
Yelan Zhu ◽  
Huihui Wang ◽  
Zhe Meng

2009 ◽  
Author(s):  
Ya Li ◽  
Xingnian Chen ◽  
Shejun Fan ◽  
Jean-Louis Briaud ◽  
Hamn-Ching Chen

2016 ◽  
Vol 845 ◽  
pp. 94-99
Author(s):  
Noegroho Djarwanti ◽  
Raden Harya Dananjaya ◽  
Fauziah Prasetyaningrum

In the construction projects, a pile group foundation is often utilized. The group of bored piles is usually installed relatively close to each other and joined at the top by a pile cap to hold up the loads. In other hand, a fast estimation of the groups of piles capacities are needed in the preliminary design and in other conditions of projects, such as a supervisor of projects want to estimate the capacities of the group of piles. The purpose of this research is to study the correlations of groups of piles efficiencies with the number of piles and to compare the groups of piles capacities with the single piles capacities. Furthermore, this study is aimed to make a fast estimation of groups of piles capacities using proposed graphical method.The piles efficiencies are calculated using several methods, such as Simplified Analysis, Converse-Labare [1][2], Los Angeles Group, Seiler - Keeney, Das, and Sayed - Baker. In order to calculate the groups of piles capacities, the capacities of single piles are needed. The singles piles capacities are taken from graphical method proposed by Djarwanti et al. (2015a and 2015b). Three graphical methods utilized are derived from the Briaud et al. (1985) , Reese and Wright (1977), and Reese O’Neill method. Moreover, the proposed graphical method is applied in the case study. The case study takes palace in Graha Indoland Condotel Inside Yogyakarta Construction Project.The pile efficiency graph is recommended for this research since the value of pile efficiency could be easily taken. The value of pile efficiency for Graha Indoland Condotel Inside using Simplified Analysis, Converse - Labare, Los Angeles Group, Seiler – Keeney, Das, and Sayed – Baker are 1,75; 0,89; 0,94; 0,99; 4,00; 1,56 respectively. Meanwhile the value of pile group capacity with the value of pile group efficiency more than 1, showed that the pile group capacity based on the efficiency is bigger than the one based on single down pattern.


2019 ◽  
Vol 10 (3) ◽  
pp. 5-15
Author(s):  
M. L Nuzhdin

Often in construction practice there is a need to strengthen the pile foundation of buildings and structures. The traditional methods include the implementation of additional, as a rule, bored piles with the subsequent erection of a grillage incorporating them into operation. Often, this work has to be done in the conditions of dense urban development, in cramped rooms of the basement, etc., which leads to significant technological difficulties. One of the alternative ways to strengthen pile foundations is the method of high-pressure group injection, which consists in injecting a movable cement-sand mortar into the soil under pressure that exceeds its structural strength. As a result, after its hardening, solid injection bodies are formed at the base, reinforcing the soil base. The article describes the results of experiments to assess the impact of the layout of hard inclusions on the deformability of the soil foundation of the pile foundation model. The experiments were carried out in a small soil tray, which was filled with medium-grained loose sand. The piles were modeled with metal rods, the pile grillage with a metal square stamp. The pile foundation model included 9 piles arranged in a square grid. As injection bodies, gravel grains of various sizes and shapes were used. The studies included 10 series of experiments (each experiment was repeated at least 3 times): the volume of the inclusions used, their sizes, the positioning step in the plan and in depth varied. As a result of the analysis of the performed experiments, conclusions were formulated regarding the purpose of the optimal layout of hard inclusions when strengthening the soil foundation of pile foundations by high-pressure injection of mobile cement-sand mixtures.


2012 ◽  
Vol 203 ◽  
pp. 325-328
Author(s):  
Xin Jie Chu

This paper analyzes the stability and structural optimization of self-elevating platform pile foundation, preliminarily discusses the method of analyzing the bearing capacity of the layer soil foundation, and establishes the numerical computation models for the whole platform, pile, pile shoe, etc. Besides, through these analyses, the pile structure is optimized, and the stress concentration in the joint between pile and pile shoe is reduced. Also, this study is of reference value for the analysis on the self-elevating platform pile foundation design and the platform operation stability.


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