Bearing Capacity Of Bored Piles Research Articles

Study of The Axial and Lateral Bearing Capacity of Bored Piles Affected by Liquefaction

Abstract Liquefaction can lead to structural failure as it reduces the bearing capacity of building foundations. This phenomenon occurs in saturated sandy soils where pore water pressure increases, significantly decreasing effective soil stress. Evaluating the axial and lateral bearing capacity of bored piles affected by liquefaction is crucial to ensure the stability and performance of foundation systems. This study focuses on assessing the capabilities of bored piles in the Governor’s Office of Sulawesi Barat Province, which are influenced by liquefaction phenomena. The empirical approach applied the O’Neill and Reese 1989 method, while the numerical approach used RS Pile. The calculation results revealed decreased axial bearing capacity under liquefaction conditions. In non-liquefaction, PC.4 can withstand up to 24946 kN, with displacements of 0.94 cm (x), 0.39 cm (y), and 1.12 cm in settlement. In liquefaction, it decreases to 2876.78 kN, with displacements of 1.32 cm (x), 0.86 cm (y), and 1.68 cm in settlement. In non-liquefaction, PC.3 can withstand up to 17407.93 kN with displacements of 0.02 cm (x), 0.04 cm (y), and 0.06 cm in settlement. In liquefaction, it decreases to 1713.05 kN, with displacements of 0.02 cm (x), 0.05 cm (y), and 0.07 cm in settlement.

Analisis Daya Dukung Fondasi Bored Pile Pada Rumah Sakit Sultan Imanuddin Pangkalan Bun

This study intended to analyze the bearing capacity of single bored pile, the bearing capacity of the bored pile group, the load carried, the safety factor, and the settlement that occurs. The first calculation method is Schmertmann and Nottingham method, and the second calculation method is Meyerhof method. Based on the calculation of the bearing capacity of a single bored pile using the Schmertmann and Nottingham method obtained a value Qu = 49005,88 kN, while the Meyerhof method obtained a value Qu = 1633.71 kN. The calculation results for bearing capacity of the pile group using the Schmertmann and Nottingham method obtained a value Qg = 164169,70 kN and the Meyerhof method obtained a value Qg = 5472.93 kN. The results of the load carried by the bored pile group using Schmertmann and Nottingham method is Qi = 353.98 kN ≤ Qg = 164169.70 kN which means it’s still within safe limits. Using the Meyerhof method is Qi = 353.98 kN ≤ Qg = 5472.93 kN which means it is still within safe limits. The safety factor using the Schmertmann and Nottingham method obtained SF = 463.78 and using the Meyerhof method obtained SF = 15.46 which means it is very safe. Total settlement of a single bored pile is S = 0.0142 m ≤ 0.04 m which means it is safe. And the settlement of the bored pile group is Sg = 0.03 m ≤ 0.08 m which also means it is safe

Effect of Base Grouting on the Bearing Capacity of Bored Piles

Post-grouting is a widely used technology for ground improvement and the strengthening of bored pile foundations. In situ experiments have shown that post-grouting is effective in improving the bearing capacity of bored piles. However, due to the cost and complexity of the in situ tests, the total number of test piles is limited. Therefore, it is not surprising that uncertainty is always associated with the collected data. This may significantly affect the conclusion of analyses, and most current studies have neglected this effect. In this paper, statistical analyses were carried out in order to investigate the effect of uncertainties in the data and the impact of post-grouting on the bearing behaviors of bored piles. The results show that post-grouting can significantly improve the bearing behavior of piles. This study is expected to provide technical guidance for post-grouting in foundation engineering.

Finding reserves of bearing capacity of bored piles

In recent years, due to population growth plans and accelerated economic development, high-rise buildings have become increasingly common in many cities and megapolises around the world. Due to the development of engineering construction, the type and technology of pile footing, which form the basis of such buildings, as well as the control of both single piles and a group of piles, have been significantly improved. At the same time, today the task of adequate assessment of the pile load capacity and justification of effective methods of revealing the reserves of its increase is actualized, because the manufacturing technology is constantly developing, in addition, often the functional purpose of the building itself, the type and intensity of the loads acting on it change. In view of the above, the purpose of the article is to investigate modern scientific- methodological approaches to search for reserves of bored pile load capacity. In order to carry out the study, the article used numerical methods for analyzing the stress-strain state of piles and means of the software package "Plaxis 3D Faundation". In the course of empirical experiments, it was found that the most acceptable results in the load testing of bored piles are given by the Shen method. Besides, the comparison of the results of static probing and static tests with theoretical calculations allowed to reveal the reserves of the actual pile load capacity, and also to determine on what parameters of its installation and characteristics the difference in load capacity depends more: the soil sciences in the pile base, pile diameter, pile length. Theoretical significance of the obtained results lies in the development of methodology for identifying reserves to increase the load capacity of bored piles. Conclusions have practical value that can be used in the process of laying the foundation of high-rise buildings to optimize the number and geometry of pile placement taking into account the reserve of their bearing capacity.

Estimation of ultimate bearing capacity of bored piles using machine learning models

The ultimate bearing capacity of bored piles is an essential parameter in foundation design of structure. In the present study, three Machine Learning (ML) methods namely Adaptive Neuro-Fuzzy Inference System (ANFIS), Support Vector Machine (SVM) and Artificial Neural Network (ANN) were utilized to estimate bearing capacity of bored piles based on limited engineering parameters of pile and soil obtained from 75 test sites in Vietnam. These parameters include pile diameter, pile length, tensile strength of main longitudinal steel bar, compressive strength of concrete, average SPT index at the tip of the pile, average SPT index at the pile body. Validation of the methods was verified using standard statistical metrics namely Root Mean Square Error (RMSE) and Correlation coefficient (R). The results show that all the proposed models have good potential in predicting correctly bearing capacity of bored piles on training data (R>0.93) and on testing data (R>0.88) but performance of the SVM model is the best (R:0.985 (training) and R:0.958 (testing). Thus SVM model can be used for the accurate prediction of ultimate bearing capacity of bored piles for proper designing of the civil engineering structure foundation.

NUMERICAL ASSESSMENT OF CARRYING CAPACITY AND ANALYSIS OF PILOT BARETT BEHAVIOR IN GEOLOGICAL CONDITIONS OF VIETNAM

The article provides an analysis and comparison of the bearing capacity of barrett piles in difficult geological conditions at a construction site in Hanoi - Vietnam based on the results of analytical calculations using various methods. In particular, it contains calculation results according to Building Code of Russian Federation SP 24.13330.2011 "Pile foundations" [1], by numerical modeling of the pile operation under load using the PLAXIS 3D and MIDAS GTS NX software package, based on the results of field tests with piles (static load method). It is noted that the bearing capacity of bored piles and barret piles, according to the results of full-scale static tests with a limiting settlement of 40 mm, is in good agreement with the numerical solution (with the adopted soil model Hardening Soil (HS)) and with the calculation by the analytical method according to the strength characteristics of the soil base

Топырақ массивінің DDS технологиясы бойынша орнатылған бұрғыланып толтырылған қадаларымен өзара əрекеттесуін зерттеу

The article compares the indicators of experimental and calculated bearing capacity of bored piles installed using DDS technology, according to static tests and normative calculations. The article also presents results of compression tests of soil samples around the placed piles using the Drilled Displacement System (DDS) method. The authors established dependence of the deformation properties of the soil, such as the modulus of deformation, the angle of internal friction and adhesion, on the diameter of the bored pile. The coefficient of working conditions of the soil of the lateral surface of bored piles installed using DDS technology is obtained based on the results of numerical modeling of bored piles located according to the traditional and proposed DDS method. The article describes the innovative DDS technology, explanations of the operation of the drilling auger during drilling and displacement of soil, and in general, the advantages of the above-mentioned technology and its economic efficiency.

UKRAINIAN EXPERIENCE OF COMPARING THE TEST RESULTS OF CFA PILES BY SLT AND DLT METHODS

The paper considers the domestic experience of implementing the advanced DLT method of research into the bearing capacity of bored piles which is based on principles of the stress wave theory and included in the American and European regulatory documents. The possibility of using this test method to determine the design loads on the piles has been shown. A regression model has been developed for determining the pile ultimate resistance relative to soil based on the data of the pile parallel tests using the DLT and SLT methods

ANALISIS PERBANDINGAN KAPASITAS DAYA DUKUNG PONDASI TIANG PANCANG BERDASARKAN PERHITUNGAN DAN UJI LAPANGAN PADA PROYEK PENGEMBANGAN KAMPUS POLITEKNIK NEGERI MADIUN

Polytechnic State of Madiun development project is the multi-storey building that consist of 4 floors with a 8450 m2 total building area. The project was originally planned to use a bored pile 23 m depth. Taking into consideration of implementation efficiency, the author compared the initial application planning between bored pile and spun pile. Static analysis used Autodesk Robot Structural Analysis Professional 2018 and the loading used PPIUG 1983. Soil data N-SPT point DB-3 was used as reference calculation. Implementation used Drop Hammer machine then cost estimation calculation used HSPK Madiun. From the analysis result, it was found that the largest combination load was column 11 (Portal G A 11) and column 12 (Portal G As 12) with the 485.188,48 kg LRFD combination load and 380307,72 kg ASD combination load. The bearing capacity of spun pile was 130,025 ton while bearing capacity group was 589,887 ton with the decrease of total foundation was 8,880 cm. It needed Rp. 9.390.264.961. Different from spun pile, the bearing capacity of bored pile was 139,229 ton while bearing capacity group was 595,792 ton with the decrease of total foundation was 9,464 cm. It costed Rp. 15.248.960.510. Furthermore, based on bearing capacity calculation, implementation, and cost, Spun pile was the most efficient and lowest cost.

Justification and selection of rational parameters of drilling piles of engineering structures (on the example of soil conditions of the Chayandinskoye oil and gas condensate field)

Solving the problem of rational use of building materials in the development of new fields helps to minimize ineffective consumption of applied resources. The purpose of the conducted research was to develop recommendations on the selection of rational parameters of drilling piles for engineering structures constructed on soils of the Chayandinskoye oil and gas condensate field. Bearing capacity of a base of a vertically loaded friction pile was calculated by means of existing methods. Selection of specific bearing capacity as a target parameter characterizing the efficiency of building materials and bearing capacity enabled to give a comprehensive estimate of influence of structural parameters and natural factors on bearing capacity of bored piles in a foundation soil. A complex nature of pile geometric characteristics and ground conditions’ influence on the target parameter was established during theoretical calculations. For geotechnical conditions of the Chayandinskoye oil and gas condensate field, it was established that the use of piles with a bigger diameter of 0.4-0.5 m and the length of 6 m in soils with a temperature of no more than -2.0 °C and an ice content of no more than 0.2 is rational. Practical recommendations to use the results obtained during the performed studies can reduce inefficient costs of not only material, but energy and time resources in conditions of remote industrial facilities and logistics bases.

Оценка несущей способности свай при испытании статической нагрузкой

The purpose of this research is to estimate the bearing capacity of bored piles with broadening, formed by stone rolling. A series of static tests of the existing piles was performed in accordance with the requirements of the current regulatory documentation, the analysis of the obtained results was carried out. According to this experimental researches, was made a conclusion about the advisable to take into account the standard values of settlements at the determining of the bearing capacity of piles by ground. The results of field tests were compared with the calculated values, determined by calculation with the recommendations of SP 24.13330.2011. Noted, that the value of load, corresponding to the moment of the pile «failure», should be taken as a criterion of the factual bearing capacity.

Effect of a ventilated open structure on the stability of bored piles in permafrost regions of the Tibetan Plateau

Temperature is a key factor that affects the adfreeze strength between frozen soil and a structure. Under the influence of climate change, permafrost degradation reduces the bearing capacity of bored piles in permafrost regions. Based on the monitoring results of bored piles at a site in Beiluhe and related simulations, the effect of a ventilated open structure (VOS) on the temperature at the pile-soil interface and the bearing capacity of bored piles was discussed. The results showed that climate warming can significantly reduce the bearing capacity of bored piles. The higher thermal conductivity of concrete than frozen soil had a negligible influence on thermal stability of pile. However, the temperature at the pile-soil interface decrease drastically within a year due to the lower surface boundary temperature beneath a VOS. Numerical simulation indicated that the bearing capacity of bored piles with a VOS increases during the first 25 years and then decreased. While the bearing capacity without a VOS decreases over 50 years. A VOS can improve the stability of bored piles, delay bearing capacity degradation of bored piles for at least 50 years, and significantly reduce the design pile length.

The methodology for calculating the bearing capacity of bored piles of concretes and mortars on expansive cement under axial static load

В статье представлена методика расчета несущей способности буронабивных свай из бетонов и растворов на напрягающем цементе при работе на вертикальную статическую нагрузку, сравнение результатов расчета по предлагаемой методике с экспериментальными данными и другими методами расчета буронабивных свай. Методика позволяет определить рекомендуемые границы расположения бетонов и растворов на напрягающем цементе в свае, напряжения и деформации грунта вдоль боковой поверхности и под нижним концом сваи, повышение несущей способности сваи.

Calculation and analysis of bearing capacity reliability index of post-grouting pile

The bearing capacity of bored piles is significantly improved and the dispersion of bearing capacity is reduced obviously by employing the method of grouting. However, there is still a lack of systematic research on the calculation and analysis of the reliability index of post-grouting pile. In this paper, the static load test data of 152 non-grouted bored piles and 113 post-grouted bored piles are collected. The influence of factors such as safety factor K, types of load effect combination, and the pile diameter are taken into account. Then, the approximate probability method based on the first-order second-moment method (JC method) and Monte Carlo method is employed to analyze the reliability indexes of post-grouted bored piles and non-grouted ones.

Parameter Preferences for Length Detection of Reinforcement Cage in Bored Pile

Reinforcement cage length has a significant impact on the bearing capacity of bored piles. Accurate measurement of the cage length provides an important guideline for judging pile quality. Currently, the electric method has been widely used in detecting reinforcement cage length. However, the precision of detection results requires further improvements. This paper presents an electric potential difference method for length detection based on theoretical analyses and formula derivations. Against the numerical calculation it can be observed that detection accuracy increased along with increases in the actual skeleton length and decrease of the pile-to-borehole distance, electrode spacing, and moving step size of electrodes. Parameter preferences of length detection were recommended as follows: (1) the electric potential difference method was recommended to complete the detection when the designed length of the pile was more than 8 m; (2) the pile-to-borehole distance was suggested to be less than one-fifth of the designed cage length; (3) the electrode spacing should be no more than a hundredth of the designed cage length; (4) the moving step size was limited to less than one-tenth of the designed skeleton length, and the length was an integral multiple of the step size. Moreover, the results and recommendations were verified by physical model experiments and engineering practices.

СОПРОТИВЛЕНИЕ ПЕСЧАНЫХ И ГЛИНИСТЫХ ГРУНТОВ ПО БОКОВОЙ ПОВЕРХНОСТИ И ПОД ОСТРИЕМ БУРОВЫХ СВАЙ ГЛУБОКОГО ЗАЛОЖЕНИЯ

Introduction : Saint Petersburg is characterized by complex engineering and geological conditions due to the presence of a significant mass (with a thickness of 20…30 m or more) of highly deformable soils with deformation moduli of 5…10 MPa. Besides, due to long-term geological processes that took place in the territory of Saint Petersburg thousands of years ago, these soils are extremely unevenly distributed in depth and area of occurrence. However, according to modern requirements for city development, deeper underground structures and higher buildings are needed. In terms of geotechnical solutions, it is possible to meet these requirements by using deep piles. Purpose of the study: The authors of the paper made an approximate brief classification of the geological conditions of Saint Petersburg based on the genesis, depth of occurrence, and physical and mechanical properties, and developed a method for more accurate calculations of the bearing capacity of deep bored piles. Methods: In the course of the study, the authors performed statistical processing of 600 values of the bearing capacity of bored piles, calculated according to the requirements of standards and determined by the results of field tests. In addition, they performed a non-linear extrapolation of side friction and resistance values (for soils with a depth of up to 100 m). Results: The paper presents the assessment of the bearing capacity of bored piles depending on their depth in glacial moraine and pre-quaternary vendian deposits. Using the nonlinear extrapolation, the authors calculated the side friction and resistance under the toe of bored piles for further design of pile foundations with deep bored piles (at a depth of up to 100 m). Discussion: According to statistical studies, the actual bearing capacity of bored piles is significantly higher than the design one calculated according to the requirements of corresponding standards (by 1.6...2.6 times). This is due to the fact that soils with significantly differing strength and deformation characteristics are located along the side and under the toe of bored piles. The stronger the soil where the most part of the pile is located, the more the bearing capacity error is (towards underestimation). The paper presents studies confirming this statement.

Finite element analysis on bearing capacity of post-grouting bored pile with the HS-small model and the HS model

Based on static load test results, with consideration of the small-strain stiffness characteristic of soils, the bearing capacity of bored piles with pile-toe and pile-shaft post-grouting have been analyzed using HS-small model and HS model of Plaxis program. The analysis reveals that: the small-strain stiffness of soil is not negligible in analyzing pile and soil interaction; with post-grouting, the interface between pile and surrounding soil are strengthened and the performance of bored pile is improved with increased bearing capacity and reduced settlement.

АНАЛИЗ РЕЗУЛЬТАТОВ НАТУРНЫХ ИСПЫТАНИЙ БУРОНАБИВНЫХ КОНИЧЕСКИХ СВАЙ НА ДЕЙСТВИЕ РАЗЛИЧНЫХ ВИДОВ НАГРУЗОК

One of the methods of improving the bearing capacity of bored piles is giving them a taper. The feature of these (wedge-type) piles is that under load they work "as a thrust" and transfer part of the load due to the normal component to the inclined side surface. Three sizes of tapered bored piles were tested, with the length of 4.5 m, head diameter 0.4; 0.5; 0.6 m and with cone angle 1o and 2,5o. The test results were compared with the test results of cylindrical piles, 4.5 m long, with head diameter 0.4 m and 0.6 m. It has been discovered that with the increasing cone angle, the bearing capacity of piles against the pressing load, especially the specific load capacity for 1 m3 of material, as compared to cylindrical piles, increases significantly. It has been determined that the larger is the diameter of the head of the pile, the higher is the bearing capacity against the horizontal load, and the bearing capacity against the pullout load is equal to the breakout force of a pile from the soil.

Simulation of bearing capacity of bored piles

This study focuses on how one can possibly predict the ultimate load for the piles that did not reach failure. This challenge was acquired through Chin- Konder method by which, the estimated settlement that correspond to failure load is well defined. Hence, this research aims to make a comparative study between the results of pile load tests carried out in Al-Basrah sewage treatment plant project, and those results induced from the numerical analysis in term of ultimate pile capacity. Consequently, it may give a clear idea on the ability of numerical simulation in getting close to the actual behavior of piles. In the current study, a numerical study using Plaxis 3D Foundation program has been performed on bored piles by the assistance of site investigations of soil. Mohr- Coulomb and linear elastic models were adopted in the simulation for soil and pile respectively. Ten bored piles were used in this analysis under different values of loading. The diameter and length of pile are 0.6m and 24m respectively. The test results indicate that, an excellent agreement has been found as a response of pile capacity between the field and numerical studies. Also, ideal load- settlement curves were created using Chin- Konder method to predict the failure load of bored piles. Also, the results have demonstrated that, the pile capacity obtained from the simulation process is larger about 51% than that design load estimated before the design of piles. This may present a priority to use the finite element method to be accounted as an effective approach in the primary analysis.

Lateral capacity of pile with grouted upper soil: field test and numerical simulation

Laterally loaded piles may entail large deformation under some circumstances such as ship impact, earthquake and long-term horizontal thrust of arch bridges, etc. The arch bridges are especially sensitive to horizontal displacement of foundation. Lateral load test was performed on a full-scale pile in virgin soil and pile with post-grouted soil around pile. Further numerical simulation analysis was carried out by PLAXIS3D based on field test result. The analytical and measured results are found to be in fairly satisfactory agreement. According to test results of single pile, lateral response of piles largely depends on profile of limiting force in shallow soil. Horizontal bearing capacity of bored piles is improved via grouting technique. For pile with post-grouted soil around, horizontal displacement of pile top is significantly reduced. The maximum bending moments of pile with grouting decrease dramatically. The grouted upper soil expands range of effective soil around pile, and more horizontal thrust was shared.