scholarly journals Analysis of the Bearing Capacity of Helical Pile with Hexagonal Joints

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1890 ◽  
Author(s):  
Daehyeon Kim ◽  
Kyemoon Baek ◽  
Kyungho Park

This study aims to improve shafts with hexagonal joints so that they will not require welding or bolts in static load tests. In order to evaluate the bearing capacity of helical piles, two sites were selected to conduct pile installation for the field test and the pile load test. For the pile load test, a static pile load test and a dynamic pile load test were carried out, and torque was measured during pile installation in a field test to compare and analyze the expected bearing capacity and thus assess the feasibility of the method for estimating the bearing capacity. The field pile load test revealed that the bearing capacity of the gravity grout pile was the same or greater than 600 kN in the static pile load test in accordance with the AC 358 code. The non-grout pile showed a bearing capacity that was the same or smaller than 600 kN, suggesting that gravity grouting is required. Moreover, the field pile load test was used to establish the bearing capacity equation considering the torque in the pile installation, and a small number of samples were used to establish the equation, which can be used as basic data.

Author(s):  
Daehyeon Kim ◽  
Kyemoon Baek ◽  
Kyungho Park

This study aims to improve the shaft with hexagon joints to be a type not requiring welding or bolts in the static load test . In order to evaluate the bearing capacity of helical piles, two sites were selected to conduct pile installation for the field test and the pile load test. For the pile load test, the static pile load test and the dynamic pile load test were carried out, and torque was measured during pile installation for the field test to compare and analyze expected bearing capacity and thus assess the feasibility of the method for estimating the bearing capacity. The field pile load test revealed the bearing capacity of the gravity grout pile was the same or greater than 600kN in the static pile load test in accordance with AC 358 Code. The non-grout pile showed the bearing capacity the same or smaller than 600kN, suggesting gravity grouting is required. Moreover, the field pile load test was used to establish the bearing capacity equation considering the torque in pile installation, and a small number of samples were used to establish the equation which can be used as a basic data.


2015 ◽  
Vol 36 (2) ◽  
pp. 45-49 ◽  
Author(s):  
Zygmunt Meyer

Abstract Statistic load test is the most commonly used method for estimation of the bearing capacity of piles. From the test we obtain the series a values: load-settlement, Q–s curve. In practice, it is extremely difficult to reach the critical load of the pile when the settlement turns out of control. The existing methods that allow bearing capacity to be calculated give the value which is very often 1/10 of the critical load. The question arises if it is possible based upon short series of load, i.e., 0–0.4 critical load, to predict the critical value of the load, with accuracy which is sufficient for practical calculation. The paper presents a method how to calculate the critical load based upon short series of load in the static load tests.


2009 ◽  
Vol 46 (9) ◽  
pp. 1046-1061 ◽  
Author(s):  
Mohammed Sakr

The results of a comprehensive pile load-test program and observations from field monitoring of helical piles with either a single helix or double helixes installed in oil sand are presented in this paper. Eleven full-scale pile load tests were carried out including axial compression, uplift, and lateral load tests. The results of the full-scale load tests are used to develop a theoretical design model for helical piles installed in oil sand. Test results confirm that the helical pile is a viable deep foundation option for support of heavily loaded structures. The test results also demonstrated that circular-shaft helical piles can resist considerable lateral loads.


Author(s):  
A. Z. Zhussupbekov ◽  
Z. A. Shakhmov ◽  
G. T. Tleulenova ◽  
S. B. Akhazhanov

In this paper the analysis results of precast piles different tests are presented. Extreme soil conditions of Astana (Kazakhstan) involve realizing the work precast piles in various soil ground and interaction soil ground and piles. There were carried out dynamic and static load tests of piles in extreme soil ground conditions in Astana. Based on data results of pile foundations the piles bearing capacity was determined. According to the results of DLT with PDA of driving piles (30.0 cm) the bearing capacity of the piles is 911 kN. The bearing capacity of the driven piles according to the results of SLT amounted to be 878 kN. Soils physic-mechanical properties in extreme conditions of Astana along with graphs of dependence are between settlement and load. The precise analysis of climatic and geological factors of the construction sites is shown. Investigations method for precast concrete piles testing is presented. Dynamic load test methodology in Astana for concrete piles testing is shown.  These investigations are important for of Pile-Soil interaction on problematical soil ground.


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.


2000 ◽  
Vol 37 (6) ◽  
pp. 1283-1294 ◽  
Author(s):  
Caizhao Zhan ◽  
Jian-Hua Yin

The Mass Transit Railway Corporation proposes to construct the Tseung Kwan O Depot (TKD) within Area 86 reclamation at Tseung Kwan O as part of the Tseung Kwan O Extension. The proposed foundation for the TKD comprises about 1000 large-diameter, bored, cast in situ, drilled shafts founded on or socketed into rock. To confirm the design allowable end bearing capacity and rock socket side resistance for the drilled shaft foundations, two test piles were constructed and tested. Both test piles were instrumented with strain gauges and rod extensometers. This paper presents the static compressive load test results on both test piles. The test results indicate that an end bearing capacity of 20.8 MPa (design allowable 7.5 MPa) and rock socket side resistance 2.63 MPa (design allowable 0.75 MPa) are achieved during the pile load tests with no sign of failure.Key words: drilled shaft, static load test, end bearing capacity, rock socket, rock socket side resistance, load transfer.


Author(s):  
Askar Zhussupbekov ◽  
Rauan Lukpanov ◽  
Abdulla Omarov

Traditionally, pile load tests in Kazakhstan are carried out using static and dynamic load test methods. Static pile load test is the most reliable method to obtain the load-settlement relation of piles. Most of the static pile load tests are performed using reaction systems. Furthermore, cost and time for the static pile load test are relatively high compared to the dynamic pile load testing. Therefore, the number of pile load tests in construction site is limited to 2 or 5 piles in usual of constructed piles In Kazakhstan. This paper includes the short summary about dynamic and static tests by driven piles (cross-section 30×30 cm and length of 12 m). The methodologies of definition bearing capacity of the pile by aforementioned methods were also given. As an example for those methods, paper describes the results of the dynamic, traditional static and the new PDA (Pile Dynamic Analyzer) tests of cooperative work of soils and piles performed in the construction site of the New Railway Station in Astana. According to the results of tests were determined the possible depth of penetration and bearing capacity of piles, as well as recommendations on the device of working. The construction is part of the preparations for EXPO 2017. It will be 11 times bigger than the existing railway station. The height of the six-floor complex will be 49.5 metres, the width 116 metres and the length 630 metres.


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8598
Author(s):  
Michał Baca ◽  
Alexander L. Ivannikov ◽  
Jarosław Rybak

Due to the development of dedicated software and the computing capabilities of modern computers, the application of numerical methods to analyse more complex geotechnical problems is becoming increasingly common. However, there are still some areas which, due to the lack of unambiguous solutions, require a more thorough examination, e.g., the numerical simulations of displacement pile behaviour in soil. Difficulties in obtaining the convergence of simulations with the results of static load tests are mainly caused by problems with proper modelling of the pile installation process. Based on the numerical models developed so far, a new process of static load test modelling has been proposed, which includes the influence of pile installation on the soil in its vicinity and modelling of contact between steel pile and the soil. Although the presented method is not new, this is relevant and important for practitioners that may want to improve the design of displacement piles. The results of the numerical calculations were verified by comparing them with the results of pipe pile field tests carried out in a natural scale on the test field in Southern Poland.


2011 ◽  
Vol 243-249 ◽  
pp. 4402-4407
Author(s):  
Yong Hong Miao ◽  
Guo Jun Cai ◽  
Song Yu Liu

Six methods to determine axial pile capacity directly based on piezocone penetration test (CPTU) data are presented and evaluated. Analyses and evaluation were conducted on three types piles that were failed during pile load testing. The CPT methods, as well as the CPTU methods, were used to estimate the load carrying capacities of the investigated piles (Qp ). Pile load test were used to determine the measured load carrying capacities (Qm). The pile capacities determined using the different methods were compared with the measured pile capacities obtained from the pile load tests. Two criteria were selected as bases of evaluation: the best fit line for Qp versus Qm and the arithmetic mean and standard deviation for the ratio Qp /Qm. Results of the analyses showed that the best methods for determining pile capacity are the CPTU methods.


Author(s):  
Moncef Souissi

The capacity-to-torque ratio, Kt, has been used in the design of helical piles and anchors for over half a century. Numerous research efforts have been conducted to accurately predict this capaci-ty-to-torque ratio. However, almost of all these Kt factors are based on shaft geometry alone. The ca-pacity-to-torque ratio described herein was found to depend on the shaft diameter, shaft geometry, helix configuration, axial load direction, and installation torque. In this study, 799 full scale static load tests in compression and tension were conducted on helical piles of varying shaft diameters, shaft geometry, and helix configurations in different soil types (sand, clay, and weathered bedrock). The collected data were used to study the effect of these variables on the capacity-to-torque ratio and resulted in developing a more reliable capacity-to-torque ratio, Km, that considers the effect of the variables mentioned above. The study shows that the published Kt values in AC358 (ICC-ES Acceptance Criteria for Helical Piles Systems and Devices) underestimate the pile capacity at low torque and overestimate it at high torque. In addition, and based on probability analysis, the predicted capacity using the modified Km results in a higher degree of accuracy than the one based on the published Kt values in AC358.


Sign in / Sign up

Export Citation Format

Share Document