{"id":804,"date":"2010-10-23T01:09:45","date_gmt":"2010-10-22T18:09:45","guid":{"rendered":"https:\/\/lethycorp.com\/?p=804"},"modified":"2023-08-25T16:41:17","modified_gmt":"2023-08-25T09:41:17","slug":"collect-your-wish-to-coc","status":"publish","type":"post","link":"https:\/\/lethycorp.com\/en\/hoi-dap\/thu-tai-mong-coc.html","title":{"rendered":"Outline of pile foundation load test"},"content":{"rendered":"

The pile foundation load test is to determine the limit load according to the soil foundation of the pile corresponding to the expected design depth, thereby officially deciding the mass cast pile length and pile layout diagram. Load testing of pile foundations is carried out according to the following content:<\/span><\/p>\n\n\n

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Outline of pile foundation load test<\/strong><\/h6>\n\n\n\n

1. DYNAMIC TEST<\/span><\/span>
1.1 Number of piles to test the pile foundation load: write the number of test piles, with attached drawings<\/span>
1.2 Pile foundation load test specifications<\/span>
Pile type: Use M300 reinforced concrete pile, cross section 25 cm x 25 cm<\/span>
Pile length: L = 24 m, including 2 segments in a combination of 12 m (head segment) + 12 m (nose segment)<\/span><\/p>\n\n\n\n

1.3 Pile tip height: Estimated \u2013 18.80 m<\/span>
1.4 Technical requirements<\/span> when testing the pile foundation load<\/p>\n\n\n\n

Preparation<\/span> for pile foundation load testing
\u2013 The test pile driving platform must be prepared to be sufficiently rigid so that it does not shake during driving, which would reduce the impact energy of the hammer.<\/span>
\u2013 Type of hammer: Use an impact hammer with a falling weight of 1800 kg to 2500 kg and a minimum impact energy of 4000 kgm.<\/span>
\u2013 Pile quality: piles must be manufactured according to the design drawings and must undergo quality inspection before driving.<\/span>
Regulations while <\/span>pile foundation load test<\/p>\n\n\n\n

\u2013 When the pile tip is still 1 meter away from the planned design elevation, but the refusal has already reached 2 mm\/stroke.<\/span>
\u2013 When the pile tip has reached the planned design elevation and the refusal reaches 2mm< e \u2264 4mm<\/span>
\u2013 When the pile tip reaches the planned design elevation but the resistance is still greater than 4mm\/stroke, driving must continue until one of the following two conditions is met:<\/span><\/p>\n\n\n\n

Density e \u2264 4 mm<\/span>
Maximum additional closing length is 1 m<\/span>
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Regulations when <\/span>pile foundation load test
\u2013 Wait 3 days after the pile driving is finished, then hammer again with 3 rounds of hammering, 20 blows each round.<\/span><\/p>\n\n\n\n

\u2013 Conditions for concluding pile foundation load testing: The refusal of the pile after re-tapping must reach 2mm to 3mm\/per tap. If the above refusal is not met, inform Party A and the design agency to coordinate corrective action.<\/span><\/p>\n\n\n\n

\u2013 Document all pile driving activities from the start of pile driving to the completion of the test pile work, under the supervision of the supervising consultant.<\/span>
The implementation of test pile driving will be approved by the competent authority<\/span><\/p>\n\n\n\n

2. STATIC TEST<\/span><\/span>
The pile foundation load test aims to determine the limit load according to the soil foundation of the pile corresponding to the expected design depth, thereby officially deciding the mass cast pile length and pile layout diagram. Test pile pressing is carried out according to the following content:<\/span><\/p>\n\n\n\n

2.1 Test method: static test<\/span>
2.2 Test pile<\/span>
Reinforced concrete pile M300, size 25\u00d725 cm. Length = 30m (combined 10m + 10m + 10m tip sections)<\/span>
Pile structure: as shown in the drawing<\/span><\/p>\n\n\n\n

Piles used for pressing must have a complete factory history, ensuring quality and strength according to the prescribed design.<\/span>
Pile tip height:<\/span>
Calculated load capacity of pile Ptt = 30 T<\/span>
Number of test piles<\/span><\/p>\n\n\n\n

2.3 Test pile location: see attached drawing<\/span>
2.4 Select pressing equipment<\/span>
Based on the test load of 50 T, a hydraulic pile jacking device with a minimum pile pressing capacity of 70 T will be selected.<\/span><\/p>\n\n\n\n

The accuracy of the pile head displacement meter is required to be at least 0.01 mm. The pressure gauges must be inspected by a specialized agency immediately before the load test.<\/span>
The positioning system, jacking and pressing piles must meet the requirements: keep the pile position stable on the ground.<\/span><\/p>\n\n\n\n

2.5 Sequence of pressing and static testing<\/span>
a) Pressing sequence<\/span>
Condition for stopping pressing:<\/span>
\u2013 The pile tip reaches the planned design elevation of 25.75 m and the minimum driving force is 50 T.<\/span>
\u2013 The driving force must reach a minimum of 50 T, and the pile must be driven into the good soil layer for a distance of at least 1 m (the depth of immersion in good soil is assessed through the jacking pressure: calculated from the moment the jacking pressure increases dramatically, expected to be around 40 T or more).<\/span><\/p>\n\n\n\n

Note:<\/span>
\u2013 The jacking and pile driving positioning system must be accurate, properly aligned with the pile center, and not exert lateral pressure on the pile head.<\/span>
\u2013 The pile driving and joining process is carried out in strict accordance with the procedures and requirements of the pile driving process.<\/span>
\u2013 Record the change in compressive force during each 1-meter interval.<\/span>
\u2013 When the pile makes good contact with the soil (sudden increase in force and > 40 T), record the change in compressive force in each 20 cm segment.<\/span><\/p>\n\n\n\n

b) Static suicide sequence<\/span>
c\/ Notes<\/span>
Condition for increasing load level: load is increased by one level if after one hour of observation the pile settlement is less than 0.20mm and gradually decreases after each reading in the above time period.<\/span><\/p>\n\n\n\n

Record the load and settlement during the loading process<\/span>
\u2013 Every 15 minutes during the loading period<\/span>
\u2013 Every 30 minutes during a loading period of 1 to 6 hours<\/span>
\u2013 Every 60 minutes during loading times >6 hours<\/span><\/p>\n\n\n\n

Record load and settlement during load reduction: Load, settlement and time are recorded immediately after being reduced to the corresponding level and as soon as starting to reduce to the new level.<\/span>
Unloading conditions<\/span>
\u2013 When the load reaches 50T and the load holding time is as prescribed.<\/span>
\u2013 When at any load level less than 50T, the total settlement caused by the test load exceeds 45 mm, or the settlement after 1 hour of observation following the specified holding time is greater than 0.2 mm and increases gradually after each reading within that time period.
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Contact information:<\/strong><\/p>\n\n\n\n