• Proceedings of the Korean Geotechical Society Conference
• /
• 1994.09a
• /
• pp.87-93
• /
• 1994

Factors which affect the capacity and the soil plug condition of an open-ended pile can be broadly divided into three categories:i.e., pile conditions, soil conditions and penetration methods. It has been found that the relative density and the horizontal stress have much effects on the soil plug behavior than other soil conditions. Also, it has been found that the pile diameter is the most important factor among pile conditions. However, a few investigations have been performed to account for both soil conditions and pile conditions. In this paper, a number of calibration chamber tests have been conducted with three different sized open-ended model piles. The model pile was driven into siliceous sand, with varying soil conditions, to clarify coupled effects of pile diameter and soil conditions on the plug behavior, the capacity, and the load trasfer mechanixm of soil plug. The model piles are composed of two stainless steel pipes so as to measure the plug capacity, the tip resistance, and the outside skin friction. separately.

• Journal of the Korean Geotechnical Society
• /
• v.17 no.6
• /
• pp.99-110
• /
• 2001

Open-ended pipe piles are often used for the foundations of both land and offshore structures because of their relatively low driving resistance. In this study, load tests were performed on model pipe piles installed in calibration chamber samples in order to investigate the effects of pile installation method on soil plugging and bearing capacity. Results of the test program showed that the incremental filling ratio (IFR), which is used to indicate the degree of soil plugging in open-ended piles, decreased (i) with increasing hammer weight for the same driving energy and (ii) with increasing hammer weight at the same fall height. The base and shaft resistance of the piles were observed to increase (i) with increasing hammer weight for the same driving energy and (ii) with increasing hammer weight at the given same fa11 height. The jacked pile was found to be have higher bearing capacity than an identical driven pile under similar conditions, mostly due to the more effective development of a soil plug in jacking than in driving.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.03a
• /
• pp.107-141
• /
• 2000

Large diameter piles can be defined as piles with diameter of at least 0.76 m (2.5 ft). In bridge foundation, large diameter piles have been used as pier foundations and their use has been increased greatly. In this study, static pile load tests for large diameter piles peformed in Kwangan Grande Bridge construction site were introduced. Also, various sensor installation methods for several types of piles (that is, open-ended steel pipe pile, drilled shafts and socketed pipe piles), pipe axial load measuring method, load transfer analysis method and pile load test results (pile-head load - settlement curve, and pile axial load distribution curve along the pile depth) were introduced.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.70-77
• /
• 2010

In this paper, a case study of drivability and bearing capacity of large diameter steel pipe piles at PTT LNG site in Thailand is introduced. The LNG facilities were designed to be founded on steel pipe pile foundations driven into the weathered rock formation overlaid by sand layers. The drivability analyses of open ended pipe piles were carried out using GRL WEAP program and the bearing capacities of the piles were estimated. Dynamic load tests were performed to evaluate end bearing resistance, and it is shown that the measured end bearing resistance is smaller than the calculated end bearing because the plugging does not develop sufficiently in case of large diameter pipe piles.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2002.03a
• /
• pp.589-596
• /
• 2002

In this study, static pile load tests with load transfer measurement were accomplished in the field. Yield pile capacity (or ultimate pile capacity) determined by load-settlement-time relationship was determined and axial load transfer behavior was analyzed. In the test for the four test piles were behaved as end bearing pile but ratios of skin friction to total pile capacity were 27%∼33%.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.1140-1147
• /
• 2010

To find the soil plug of steel piles shaped by jet grouting, 4 blocks of cement milk with cube of 1.2m were made. 4 open-ended steel piles on the blocks were rested. The inner end part of 2 the piles was not reinforced. Cement milk 65%(SIG-1) and 100%(RJP-1) were filled into the block and height of 4.2 times of inner the pile diameter respectively. And the other the piles were welded 2 steel ring. The filling of the cement milk was an equal method as before(SIG-2 and RJP-2). Also the strain gauges were installed and the static pile load tests were done at the piles all. As a result, list in great order for effect of soil plug was (1)SIG-1, (2)SIG-2, (3)RJP-1, (4)RJP-2. This is because of strength and filling height of cement milk. And the higher the strength is, the greater the confining coefficient is.

• Journal of the Korean Geotechnical Society
• /
• v.19 no.2
• /
• pp.49-55
• /
• 2003

In this study, based on the relationship of the vertical force - settlement of batter piles obtained by pressure chamber model tests, the vertical bearing capacity of vertical and batter piles according to the increase of pile inclination was analyzed. A model open - ended steel pipe pile with the inclination of 5$^\circ$, 10$^\circ$ and 15$^\circ$ was driven into saturated fine sand with relative density of 50 %, and the static compression load tests were performed under each confining pressure of 35, 70 and 120 kPa in pressure chamber. The vertical bearing capacity of pile obtained from pressure chamber tests increased with the pile inclination. In the case of the inclination of 5$^\circ$, 10$^\circ$, 15$^\circ$, increasing ratios of pile bearing capacity were 111, 121, 127 ~ 140 % of vertical bearing capacity respectively. In the case of the inclination of above 20$^\circ$, the model tests could not be performed because of pile of pile head during compressive loading on the pile head.

• Geomechanics and Engineering
• /
• v.15 no.1
• /
• pp.695-710
• /
• 2018

Formation of a soil plug in an open-ended pile is a very important factor in determining the pile behavior both during driving and during static loading. The degree of soil plugging can be represented by the incremental filling ratio (IFR) which is defined as the change in the plug length to the change of the pile embedment length. The experimental tests carried out in this research contain 138 tests that are divided as follows: 36 tests for single pile, 36 tests for pile group ($2{\times}1$), 36 tests for pile group ($2{\times}2$) and 30 pile group ($2{\times}3$). All tubular piles were tested using the poorly graded sand from the city of Karbala in Iraq. The sand was prepared at three different densities using a raining technique. Different parameters are considered such as method of installation, relative density, removal of soil plug with respect to length of plug and pile length to diameter ratio. The soil plug is removed using a new device which is manufactured to remove the soil column inside open pipe piles group installed using driving and pressing device. The principle of soil plug removal depends on suction of sand inside the pile. It was concluded that the incremental filling ratio (IFR) is changed with the changing of soil state and method of installation. For driven pipe pile group, the average IFR for piles in loose is 18% and 19.5% for L/D=12 and 15, respectively, while the average of IFR for driven piles in dense sand is 30% and 20% for L/D=12 and L/D=15 respectively. For pressed method of pile installation, the average IFR for group is zero for loose and medium sand and about 5% for dense sand. The group capacity increases with the increase of IFR. For driven pile with length of 450 mm, the average IFR % is about 30.3% in dense sand, 14% in medium and 18.3% for loose sand while when the length of pile is 300 mm, the percentage equals to 20%, 17% and 19.5%, respectively.

• Journal of the Korean Geosynthetics Society
• /
• v.22 no.1
• /
• pp.39-51
• /
• 2023

The bearing capacity of the prebored pile has been studied by many researchers. However, The bearing capacity of the prebored pile has been studied by many researchers. However, comparative studies between design data and pile load test data on the load sharing ratio and the settlement were insignificant. Therefore, the design data and the static load test results were compared for the prebored open-end steel piles. In the compressive static pile load test, the load sharing ratios of the base resistance and the shaft resistance were 13%~40% and 60%~87%, respectively and the settlements were measured 2.2mm~4.7mm. In the current bearing capacity calculation formula, the base resistance was shared between 54% and 75%, and the shaft resistance was shared between 25% and 46% and the settlements were calculated about 19.8mm~23.6mm. The settlement in the current bearing capacity calculation formula was 321% to 776% (average : 445%) larger than the settlement in the result of load test. When the settlement were calculated using the load sharing ratio in the pile load tests, it was 137% to 525% larger than the test settlement, and it was as large as 204% on average. It was confirmed that an appropriate evaluation of the load sharing ratio had an important effect on the calculation of pile settlement.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03b
• /
• pp.11-19
• /
• 2004

When pile foundation constructed by driving method, it is desirable to perform monitoring and estimation of pile drivability and bearing capacity using some suitable tools. Dynamic Pile Monitoring yields information regarding the hammer, driving system, and pile and soil behaviour that can be used to confirm the assumptions of wave equation analysis. Dynamic Pile Monitoring is performed with the Pile Driving Analyser. The Pile Driving Analyser (PDA) uses wave propagation theory to compute numerous variables that fully describe the condition of the hammer-pile-soil system in real time, following each hammer impact. This approach allows immediate field verification of hammer performance, driving efficiency, and an estimate of pile capacity. The PDA has been used widely as a most effective control method of pile installations. A set of PDA test was performed at the site of Donghea-1 Gas Platform Jacket which is located east of Ulsan. The drilling core sediments of location of jacket subsoil are composed of mud and sand, silt. In this case study, the results of PDA test which was applied to measurement and estimation of large diameter open ended steel pipe pile driven by underwater hydraulic hammer, MHU-800S, at the marine sediments were summarized.