Analysis of laterally loaded large-diameter bored piles in Hong Kong

2000 ◽  
Author(s):  
Chung Nga Nip
Keyword(s):  
Hong Kong ◽  
Large Diameter ◽  
Bored Piles ◽  
Laterally Loaded

scholarly journals In Situ Lateral Load Tests on Instrumented Bored Piles in Loessial Soils

2017 ◽  
Vol 13 (1) ◽  
pp. 1-11
Author(s):  
Sebastian Drăghici ◽  
Anatolie Marcu
Keyword(s):  
Large Diameter ◽  
In Situ Tests ◽  
Laterally Loaded Piles ◽  
Natural Moisture Content ◽  
Load Tests ◽  
Bored Piles ◽  
Strength And Stiffness ◽  
Laterally Loaded ◽  
Plaxis 3D

Abstract The aim of the paper is to provide some aspects regarding the behaviour of laterally loaded piles in loessial soils, by presenting and analysing the results of several in situ tests on large diameter bored piles in this type of soil. The major feature of loess is that it exhibits a massive decline of its strength and stiffness parameters when it comes into contact with water, leading to the collapse of its structure even under self-weight and creating difficult conditions for foundations. The load tests were performed both in natural moisture content loess and also in saturated loess. The results obtained by means of instrumentation are back-analysed using current analytical methods and also by finite element method using a numerical model in the geotechnical computation software Plaxis 3D.

scholarly journals Accuracy and precision of the CSLT measurement system: An experiment to defect diagnoses in bored piles

2021 ◽  
Vol 28 (4) ◽  
pp. 176-185
Author(s):  
Zezhong Wang ◽  
Eric Tak Cho Ho ◽  
Inez Maria Zwetsloot
Keyword(s):  
Hong Kong ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Large Diameter ◽  
Housing Projects ◽  
Bored Pile ◽  
Accuracy And Precision ◽  
Bored Piles ◽  
Pile Type ◽  
Sonic Logging

A new measurement system called Crosshole Sonic Logging Tomography (CSLT) provides information on the size, shape, and orientation of defects in a bored pile. The CSLT measurement system has not (yet) been accredited in Hong Kong for foundation testing. Bored piles in Hong Kong are generally wide and deep. Existing measurement accuracy studies do not consider this large type of bored piles. The objective of this research is to quantify the measurement accuracy and precision of the CSLT method for large diameter bored piles (the most common pile type for public housing projects in Hong Kong). A test pile was constructed with known defects and perform experiments with a CSLT measurement system to quantify its accuracy and precision. CSLT is found to be accurate in detecting shape, size, and location of large defects but small defects close to the tube are difficult to detect. Generally speaking, CSLT has satisfactory accuracy and precision for practical use. The use of CSLT can be considered as a feasible method in defect diagnosis of bore piles in Hong Kong.

scholarly journals Potential and prospects of photocatalytic disinfection: using sustainable solarenergy- driven photocatalysts

2021 ◽  
Vol 28 (4) ◽  
pp. 165-175
Author(s):  
Juhua He ◽  
Kenny W K Hui ◽  
Irene M C Lo
Keyword(s):  
Hong Kong ◽  
Measurement System ◽  
Measurement Accuracy ◽  
Large Diameter ◽  
Housing Projects ◽  
Bored Pile ◽  
Accuracy And Precision ◽  
Bored Piles ◽  
Pile Type ◽  
Sonic Logging

A new measurement system called Crosshole Sonic Logging Tomography (CSLT) provides information on the size, shape, and orientation of defects in a bored pile. The CSLT measurement system has not (yet) been accredited in Hong Kong for foundation testing. Bored piles in Hong Kong are generally wide and deep. Existing measurement accuracy studies do not consider this large type of bored piles. The objective of this research is to quantify the measurement accuracy and precision of the CSLT method for large diameter bored piles (the most common pile type for public housing projects in Hong Kong). A test pile was constructed with known defects and perform experiments with a CSLT measurement system to quantify its accuracy and precision. CSLT is found to be accurate in detecting shape, size, and location of large defects but small defects close to the tube are difficult to detect. Generally speaking, CSLT has satisfactory accuracy and precision for practical use. The use of CSLT can be considered as a feasible method in defect diagnosis of bore piles in Hong Kong.

scholarly journals Influence of a permanent liner on the skin friction of large-diameter bored piles in Hong Kong granitic saprolites

2003 ◽  
Vol 40 (4) ◽  
pp. 793-805 ◽  
Author(s):  
S -C.R Lo ◽  
K S Li
Keyword(s):  
Numerical Simulation ◽  
Hong Kong ◽  
Skin Friction ◽  
Large Diameter ◽  
Full Length ◽  
Load Test ◽  
Test Results ◽  
Local Method ◽  
Bored Pile ◽  
Bored Piles

The skin friction of large-diameter bored piles in Hong Kong granitic saprolite manifested high variability. The influence of one construction detail, a full-length permanent liner, is studied by examining full-scale load test results and by numerical simulation of this construction detail. It is concluded that the use of a full-length liner will give very low skin friction because the local method of constructing a large-diameter bored pile with a full-length permanent liner leads to a significant reduction in radial stress acting on the pile–soil interface.Key words: construction, pile, stress, skin friction, numerical simulation.

Cyclic Loading of Piles Using the P-Y Method

2019 ◽  
Vol 13 (2) ◽  
Author(s):  
Matt Bristow
Keyword(s):  
Cyclic Loading ◽  
Soil Depth ◽  
Large Diameter ◽  
Reference Conditions ◽  
Numerical Procedure ◽  
New Method ◽  
Shear Stresses ◽  
Applied Loading ◽  
Cyclic Degradation ◽  
Laterally Loaded

A new analytical method is presented to determine the effects of cyclic loading on laterally loaded piles. The method uses a new numerical procedure to quantify the effects of the cyclic loading at each soil depth and convert that to a set of cyclic p-y modifiers. The reduced foundation stiffness associated with the cyclic loading can be determined, including the residual static capacity and an estimate of the accumulated displacement. The new method introduces the concept of cyclic degradation damage, which is defined as sum of the cyclic degradation that is occurring at each soil depth. Cyclic degradation calculations are based on the shear stresses in the soil. Consequently, anything that causes the shear stresses to change (e.g. pile length, pile diameter, applied loading, etc.) will automatically be included in the calculation of cyclic p-y modifiers. The method has been validated by comparing the cyclic p-y curves produced using the new method with established cyclic p-y curves derived from fielding testing. The new method has also been used to investigate what happens to the cyclic p-y modifiers as one moves away from the reference conditions used to determine the established cyclic p-y curves in API RP2A (2000). The new method shows that every application (e.g. combination of cyclic loading, pile properties, and soil characteristics) has its own unique set of cyclic p-y curves, though most p-y curves fit within an upper and lower bound range. Examples are provided for large diameter monopiles.

Response of Laterally Loaded Large-Diameter Bored Pile Groups

2001 ◽  
Vol 127 (8) ◽  
pp. 658-669 ◽  
Author(s):  
Charles W. W. Ng ◽  
Limin Zhang ◽  
Dora C. N. Nip
Keyword(s):  
Large Diameter ◽  
Pile Groups ◽  
Bored Pile ◽  
Laterally Loaded

scholarly journals THE EXPERIENCE DIFFERENT OF PILING TESTING ON PROBLEMATICAL SOIL GROUND OF ASTANA, KAZAKHSTAN

2018 ◽  
Vol 14 (4) ◽  
pp. 158-171 ◽  
Author(s):  
Askar Zh. Zhussupbekov ◽  
Yoshinori Iwasaki ◽  
Abdulla R. Omarov
Keyword(s):  
Static Loading ◽  
Large Diameter ◽  
Capital City ◽  
Loading Test ◽  
Static Compression ◽  
Static Tests ◽  
Advantages And Disadvantages ◽  
Concrete Body ◽  
Static Loading Test ◽  
Bored Piles

At the present time, in Astana city is going on works by construction public transport system LRT (Light Railway Transport). LRT is an overhead road with two railway lines. The first stage of construction is including construction of overhead road (bridge) with 22,4 km length and 18 stations. The foundation of bridge is the bored piles with cross-section 1.0HL5 m and length 8-КЗ 5 m. In these conditions, very important to control integrity of concrete body of each bored piles. For checking integrity- applying two methods - Low Strain Method and Cross-Hole Sonic Logging. The aim of this paper is to discuss the advantages and disadvantages of each method using the examples of a real application. The article presents loading tests of large diameter and deep boring piles on the construction site in new capital city of the Republic of Kazakhstan. Finally, some recommendations for testmg methods suitable for problematical ground conditions of Kazakhstan are introduced. Traditionally, pile load tests in Kazakhstan are carried out using static loading test methods. Static pile loading test is the most reliable method to obtain the load-settlement relation of piles. Results of static pile tests using the static compression loading test (by ASTM). static loading test (by GOST) and bi-direction static loading test (by ASTM) methods are presented in this paper. Experienced bored piles with length of 31.5 m. diameter 1000 mm. Hereafter the results of underground testmg by the piles with the methods of vertical static tests of SLT. BDSLT and SCLT are presented, which had been made on Expo 2017 projects, buildings of Pavilion m Astana. Kazakhstan.

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