Pile load testing

[Ibrahim Atta]

I have an assignment due in a few days and i am really stressing. My lecturer is not being helpful at all and i need help from fellow students or professionals. just to steer me in the right directions

 

[BAretired]

You're not being very helpful either. What is your question? Load the pile to failure, then apply a safety factor.

 

[dik]

Document the soil. Document the equipment, the type of load cell, the measuring device. Document the load set up. Document what is considered as 'failure'. Document the load application indicating the manner of loading, any pre-loading and deformations. Test to your heart's content. It may be that the type of failure that occurs may establish what you consider as failure. Determine what the save load capacity is from the failure load. Failure may occur by load or by deformation. Often with soils the latter is the criteria. If your soil is representative, a single load test may be all that is required... sometimes two to determine that this is representative. Two tests would normally be minimum with both being within the site area and not to interfere with what you are planning to build.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Ibrahim Atta]

it is better if i email you the questions can anyone provide an e mail address

 

[BAretired]

No! Put your questions to the forum and get the benefit of everyone's knowledge and experience.

 

[Ibrahim Atta]

The project report will be an individual submission in report form based on the information acquired from data and presentations based on a series of laboratory sessions. It will consist of approximately 2000 words excluding figures and drawings etc and contribute a maximum of 40% to the total module mark.

1. You will be required to write up one of the experimental procedures in a formal report form in accordance with the guidance given below. The basis of the formal report each student will complete is indicated in Table 1.

2. Each student will also be required to process the laboratory results of the other laboratory experiment in a clear and logical form. The results must be critically reviewed and discussed and presented in separate appendices to the main report.

3. All students are required to design a pile(s) to carry a working load as given in Table 2. Note the pile will be located in a single soil system, either sand or clay. The properties of each of the soils will be those obtained from the experiments. Include a critical review of the design process.

4. The piles must be designed in accordance with Euro-code 7.

 
Group no. Piles in Sand Pile in clay
Group 1 X
Group 2 X
Group 3 X
Group 4 X


Table 1 Group Allocation for Pile Type

Group No. Permanent Load (kN) Variable Load (kN) Pile is located in
Group 1 900 250 Sand
Group 2 750 450 Clay
Group 3 750 600 Sand
Group 4 900 250 Clay


Table 2 Group Allocation for Loadings
Note, - for all conditions the water table is 1m below the ground surface

Guidance on Format of Assessment
Note: Students are reminded not to include this assignment brief with the assignment submission.
• The following should be undertaken in all cases:

(a) Abstract/Summary of your work (consisting of statement of your aims and objectives, how they were achieved, main findings and conclusions).
(b) Introduction, including a relevant and critical literature review.
(c) Main body of work consisting of critical examination/presentation of the issues involved and the required detail of the sites investigated.
(d) Discussion and Conclusions.

• All work must be well presented in terms of language, style, layout and meaningfulness of quotations, graphs and charts.
• You must demonstrate evidence of research through use of appropriate references – which must be properly cited.
Appendix B Piles in Sand - Coursework Detail
General
The apparatus consists of a large sand tank with a steel template held in a frame above the sand surface. The template has 13 symmetrically placed holes through which nine 12.5mm diameter steel piles are driven into the sand in a pre-selected pattern. The piles are driven using a small hand powered pile driver. A loading plate can be attached to an individual pile enabling it to be loaded to failure.

The resistance to driving can be measured for each pile in the group and the densifying effect of driving piled in sand can be demonstrated. Load/ settlement curves can be drawn and relationships can be analysed between penetration resistance, load bearing, settlement and pile group behaviour.

. All symbols have usual meanings.

Procedure
1. Remove or loosen sand to a depth of 450mm. Replace and or compact the sand to a uniform density.
2. Place the pile guide plate in the frame of the sand tank and select the order and pattern in which the piles are to be driven.
3. Drive each one of the nine piles to the set length using the dynamic driving system and record the blow count per 50mm of penetration.
4. Select two piles for load testing and load test each of these piles using the following procedure.
5. Attached the load plate on top of the pile and set up the dial gauge.
6. Apply load in increments to the pile until failure conditions are reached ie settlement becomes excessive in relation to the increase in load.
7. For each load increment record the pile head displacement.

Tasks
1. Produce a report in accordance with Appendix A which will include the following:
2. Produce a graph of blow count verses penetration for each of the piles.
3. Plot a graph of settlement verses load and evaluate the failure load for each of the two piles load tested.
4. Compare the failure load to that determined using the bearing capacity formula.
5. Inspect the relative performance of each pile in terms of load and settlement.
6. Critically review and discuss the results
(For students who are to write up ‘Piles in Clay’ they also need to complete tasks 2, 3, & 4 above for the ‘Piles in Sand’ and present as an Appendix).

Note – The results of a shear box test on the sand indicate an angle of internal friction for the sand of 33degrees, φ’=33o and a bulk unit weight of 16.5kN/m3.
Practical results:
pile no.
depth 1 2 3 4 5 6 7 8 9
0 0 0 0 0 0 0 0 0 0
50 0 0 0 0 0 0 0 0 0
100 0 0 0 0 0 0 0 0 0
150 0 0 0 0 0 0 0 0 0
200 8 12 12 25 24 20 22 23 24
250 12 15 17 46 34 26 39 28 28
300 13 16 20 74 30 20 19 23 25
above is the blow count values recorded at various depths. Below are the readings for the piles that were load tested.
Pile 1
dial gauge vs weight (g)
1 250
1 500
3 750
13 1000
31 1250
73 1500
218 1750
318 1850
407 1950
600 2050
Pile 9
dial gauge vs weight (g)
0 250
6 500
65 750
140 850
285 950
fail 1050

 

[Ibrahim Atta]

I am located in group 1

 

[Ibrahim Atta]

or below is the assignment for easier access

 

[Ibrahim Atta]

These are the practical results

 

[BAretired]

Your assignment is due on Jan. 24, 2024. Your 2,000 word report should be complete by this time, so that you should be reviewing it and adding the finishing touches. It is completely unrealistic to expect any help at this late date from Eng Tips. Furthermore, Eng Tips has a policy of not assisting students with homework assignments.

Put your test results together in the form of a report, commenting on each diagram and describing anything which you deem to be of interest to the reader. Getting stressed about it does not help in the least. Nobody expects you to be an expert at this stage. Just describe what you believe to be the salient features of the testing which you have already conducted.