ROCK BEARING RESISTANCE OF BORED PILES SOCKETED INTO ROCK

2016 ◽  
Vol 78 (8-6) ◽  
Author(s):  
Eda Suhaili Sharudin ◽  
Nor Zurairahetty Mohd Yunus ◽  
Aminaton Marto ◽  
Siti Norafida Jusoh ◽  
Kamarudin Ahmad ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Rock Type ◽  
Dynamic Test ◽  
Field Tests ◽  
Load Test ◽  
Static Load Test ◽  
Current Design ◽  
Bored Piles ◽  
And Performance ◽  
The Relationship

In view of the large movement required to mobilise the base resistance of bored piles and difficulty in base cleaning, the end bearing resistance often ignored in current design practice that will result in excessive rock socket length. Many attempts have been made to correlate the end bearing resistance with the uniaxial compressive strength of intact rock and the RQD but it is uncertain how applicable they are to rock type in Malaysia. This paper attempts to review the applicability of the formulas from previous studies to rock type in Malaysia. A program of field tests for 13 bored piles with diameter varying from 1000 mm to 1500 mm constructed in granite was conducted to measure the axial response of bored piles, tested using static load test and high strain load dynamic test to verify its integrity and performance. The results were evaluated and compared to the predicted rock bearing resistance. Based on the result obtained, the method by AASHTO gives the best prediction of rock bearing resistance for granite in Malaysia. However the relationship between compressive strength and rock discontinuities with the rock bearing resistance showed scattered results

scholarly journals Assessment of the bearing capacity of piles during static load test

2020 ◽  
Vol 8 (4) ◽  
pp. 22-27
Author(s):  
Pavel Gavrilov ◽  
Vyacheslav Glukhov
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Field Tests ◽  
Load Test ◽  
Static Load Test ◽  
Static Tests ◽  
Standard Values ◽  
Bored Piles ◽  
The Moment ◽  
Experimental Researches

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.

Investigation of Point Load Index Using Novel Discrete Based Model

2016 ◽  
Vol 846 ◽  
pp. 348-353
Author(s):  
Somayeh Behraftar ◽  
Joshua Heslin ◽  
S. Galindo Torres ◽  
Alexander Scheuermann
Keyword(s):  
Compressive Strength ◽  
Material Properties ◽  
Mechanical Model ◽  
Rock Type ◽  
Correlation Factor ◽  
Point Load ◽  
Load Test ◽  
Point Load Index ◽  
Bonded Particles ◽  
The One

In this study, a micro-mechanical model is developed to study the correlation of the point load index in rocks with uniaxial compressive strength (UCS) tests. The model is represented by an array of bonded particles simulated by a novel discrete based model, which was introduced by the authors previously. The point load test (PLT) is performed in the field on rock samples to classify and estimate the UCS of a rock type via the index-to-strength correlation factor k. Numerical analyses, such as the one presented in this work, will serve to close the knowledge gap concerning the correlation between k, UCS and other material properties of rocks.

The Modification to the FEM Model of the Prestressed Concrete Beam with the Combination of the Data of Static and Dynamic Test

2014 ◽  
Vol 707 ◽  
pp. 401-405
Author(s):  
Tao He ◽  
Chong Ji Zhao
Keyword(s):  
Prestressed Concrete ◽  
Static Load ◽  
Dynamic Test ◽  
Load Test ◽  
State Variables ◽  
Static Load Test ◽  
Fem Model ◽  
Modified Model ◽  
Finite Element Software ◽  
T Beam

Using the finite element software ANSYS to establish the model of prestressed concrete T beam .With the combination of dynamic and static load test data, the objective function was constructed by taking the vertical deflection of the static load test and the top five vertical natural frequency of dynamic test as state variables. The results revealed that,after being modified ,the error between the calculation value and the testal results of the model was converged in a reasonable error range.In addition ,The modified model could be used in the assessment of bridge structure performance,and it shows the practical application value.

The Settlement Prediction of Pile Foundation Based on Grey Linear Regression Model

2012 ◽  
Vol 204-208 ◽  
pp. 320-325
Author(s):  
Jia Kun Liu ◽  
Jian Ping Wang ◽  
Min Zhu ◽  
Xiao Jie Hou
Keyword(s):  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Pile Foundation ◽  
Load Test ◽  
Static Load Test ◽  
Combined Model ◽  
Actual Meaning ◽  
Relationship Of ◽  
The Relationship

Grey linear regression model is a covert grey combined model that is built based on GM(1,1) model and linear regression model. It improves undervaluation of linear regression model which can not in press the exponential growth and come to deficiency of grey GM (1, 1) model which has not linear factor. This paper briefly introduces the establishment and precision examination method of the grey linearity regression model and establishes the grey linear regression model to predict the relationship of load and settlement. Based on the data of static load test, the load-settlement curve is simulated and analyzed. The result of study shows that Grey Linear regression Model can effectively predict the settlement of pile foundation, and be of the theoretical and actual meaning for further analyzing the bearing capability of pile foundation.

Selection of Strength Standard of CTB in High-Class Highways

2011 ◽  
Vol 243-249 ◽  
pp. 4261-4264
Author(s):  
Yin Fei Du ◽  
Xin Yu
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Bottom Layer ◽  
Practical Significance ◽  
Design Strength ◽  
Cleavage Strength ◽  
Current Design ◽  
Truck Load ◽  
The Relationship ◽  
Selection Of

A reasonable design strength standard is of great practical significance for reducing pavement diseases. First, the bottom layer tensile stress of the typical pavement structure in the operating period is calculated using computer program BISAR while the overload、the interface link status and construction variability are all considered. And then the bottom layer tensile stresses of the upper and lower base are checked under truck load during construction. According to the relationship between cleavage strength (90d) and unconfined compressive strength (7d), it is deemed that the appropriate design strength standard should be 2.1MPa~3.5MPa. Finally, combined with the results of the unconfined compressive strength of core samples in the field it is proved that the current design standard is a little high.

scholarly journals Mechanical Performance of Concrete Exposed to Sewage—The Influence of Time and pH

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 544
Author(s):  
Justyna Czajkowska ◽  
Maciej Malarski ◽  
Joanna Witkowska-Dobrev ◽  
Marek Dohojda ◽  
Piotr Nowak
Keyword(s):  
Compressive Strength ◽  
Mechanical Performance ◽  
Negative Influence ◽  
Concrete Compressive Strength ◽  
Active Sludge ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
And Performance ◽  
The Relationship ◽  
Microstructure And Performance

Contact of concrete with aggressive factors, technological structures, reduces their durability through microstructural changes. This work presents the results of research on determining the influence of post grit chamber sewage and sewage from the active sludge chamber in three different environments, i.e., acidic, neutral, and alkaline, on the structure and compressive strength of concrete. Compressive strength tests were carried out after 11.5 months of concrete cubes being submerged in the solutions and compared. To complete the studies, the photos of the microstructure were done. This made it possible to accentuate the relationship between the microstructure and performance characteristics of concrete. The time of storing the cubes in both acidic environments (sewage from post grit chamber and active sludge chamber) has a negative influence on their compressive strength. The compressive strength of cubes decreases along with the time. Compressive strength of cubes increases with increasing pH of the environment.

scholarly journals Skin and Toe Resistance Mobilisation of Pile During Laboratory Static Load Test

2018 ◽  
Vol 40 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Zygmunt Meyer ◽  
Krzysztof Żarkiewicz
Keyword(s):  
Skin Friction ◽  
Laboratory Experiments ◽  
Static Load ◽  
Load Test ◽  
Static Load Test ◽  
New Approach ◽  
Two Factors ◽  
Load Tests ◽  
Friction Curve ◽  
The Relationship

Abstract This article shows the mathematical method to determine the lateral stress on the shaft and toe resistance of pile using the new approach. The method was originally invented by Meyer and Kowalow for the static load test. The approximation curve was used for the estimation of both settlement curve and toe resistance curve of the pile. The load applied at the head of the pile is balanced by the sum of two components: the resistance under the toe of the pile and the skin friction. Therefore, the settlement curve is compilation of two factors: the skin friction curve and the resistance under toe curve. The analysis was based on the verification of the methods using laboratory experiments, that is, static load tests. The results of the research allowed to determine the relationship between parameters of the Meyer–Kowalow curve. On the basis of the relationships, it was possible to determine the skin friction and the toe resistance of the pile. Mathematical analysis of curve parameters allowed to determine the influence of the toe resistance on the settlement.

Back-Analysis for Design Parameters of Large Diameter Bored Piles

2013 ◽  
Vol 671-674 ◽  
pp. 186-189
Author(s):  
Werasak Raongjant ◽  
Meng Jing
Keyword(s):  
Test Data ◽  
Load Transfer ◽  
Static Load ◽  
Large Diameter ◽  
Back Analysis ◽  
Load Test ◽  
Design Parameters ◽  
Static Load Test ◽  
Friction Resistance ◽  
Bored Piles

Field test data from three instrumented large diameter bored piles in Pattaya city of Thailand were analyzed to study the behavior of load transfer mechanism from the pile to soil. The pile load test data were obtained from conventional static load test. These bored piles used for conventional static load test have the same diameter of 0.80 m and different length in the range of 25 m to 32 m. Results from back-analysis found that the skin friction resistance, β, has the value between 0.20 and 0.64 and the bearing capacity at end of piles, Nq, which is in the range of 10 to150, is much lower than the theoretical values proposed by other researchers before.

scholarly journals Comparison of the Compressive and Tensile Strength Values of Rocks Obtained on the Basis of Various Standards and Recommendations

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1163
Author(s):  
Rafał Misa ◽  
Andrzej Nowakowski
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Applied Research ◽  
Point Load ◽  
Load Test ◽  
Transverse Compression ◽  
European Standards ◽  
American Society ◽  
The Relationship

The objective of the current study was to compare results relating to the compressive and tensile strength of rocks obtained during research undertaken according to Polish Standards (as part of the European standards known as Eurocodes), American Society for Testing and Materials (ASTM) Standards, and the recommendations of the International Society for Rock Mechanics (ISRM). A total of 130 experiments for uniaxial compression on axisymmetric samples, point loads, and transverse compression (so-called Brazilian tests) were performed on rock samples comprising granite, limestone, and sandstone. Geometric properties of the samples were selected depending on the applied research method, and the relationship between the specimen’s slenderness and shape, and the obtained values of compressive and tensile strength, were analyzed. The results of the study showed that values of compressive and tensile strength obtained in a laboratory depend significantly on specimen slenderness, different values of which are imposed by various ISRM standards and recommendations, wherein this sensitivity was much higher in the case of compressive strength. The study also raised doubt about the usefulness of the so-called point load test as a method for determination of the compressive strength of rocks and potential estimation of the tensile strength.

scholarly journals ELASTIC PROPERTIES OF ROCKS

2017 ◽  
Vol 43 (3) ◽  
pp. 1165 ◽  
Author(s):  
A. Karagianni ◽  
G. Karoutzos ◽  
S. Ktena ◽  
N. Vagenas ◽  
I. Vlachopoulos ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Laboratory Tests ◽  
Rock Type ◽  
Regression Analyses ◽  
Modulus Ratio ◽  
Elastic Parameters ◽  
Strength Parameters ◽  
The Relationship ◽  
Range Of Values

The aim of this paper is to determine the elastic parameters of some rocks and especially limestones, schist, sandstones, conglomerates, peridotites and granites using a large number of laboratory tests performed on intact rock samples. The range of values for Young`s modulus and uniaxial compressive strength is evaluated, while the relationship between elastic and strength parameters is defined. Regression analyses were applied to define relations among these parameters and the range of values of modulus ratio (MR) is estimated for each rock type.

Sign in / Sign up

Export Citation Format

Share Document