In order to find the suitability of each existing equation with the capacity of columns from static load testing, ten column load tests were conducted in two areas of the city, in which seven load tests were carried out in area-I and three in area-TI. Among all the equations, only the Mayerhof equation gave the pile capacity at the maximum locations that is close to the load test value. So, no common suitable equation was chosen to compare the pile capacity in both areas.
CHAPTER
INTRODUCTION
- General Remarks
- Background of the study
- Objective
- Statement of the Experimental Study
A soil profile has been drawn in Khulna urban area from subsoil investigations in field &. SPT value, according to zone profile, soil samples have been collected and conducted direct shear test, unconfined compression test to determine shear parameters which will be calculated to know the hearing capacity of soil at different thickness. Most of these tests have been conducted in KUET Geotechnical Laboratory and some tests have been conducted by private company through KDA, Khulna.
LITERATURE REVIEW
General
Sub- soil Condition in Khulna city area
A cast-in-situ pile is formed by drilling a hole in the ground and filling it with concrete. The casing can also be driven with a snap point at the tip, providing a shell immediately ready to be filled with concrete, or the casing can be driven at the end, with the soil trapped in the casing Cne, jeueu OUL auer we urivirig is compieteu . Commonly available patented cast-in-place piles are shell (cased) shellless (uncased) and base.
The Behavior of a Pile Under Load
- Meyerhof Suggested the Formulae for End bearing & Skin friction of Bored Pile in Non-Cohesive Soil
- Hansen's suggested the Formulae for End bearing of Bored Piles in Cohesive or Cohesion less Soil
- Burland proposed 3 Method for Skin friction of Bored Piles in Cohesion less Soil
- Vesic's Method for End bearing of Bored Piles in Cohesive or Cohesion less Soil
- Terzaghi's Method for End bearing of Bored Piles in Cohesive or Cohesion less Soil
The working load shall be considered a minimum of two-thirds of the load causing a total reduction of 3 percent of the pile diameter. For non-cohesive soil of clay, fine to medium sand, the skin friction and ultimate bearing capacities of the pile can be estimated by the following formulas suggested by Meyerhof. The value of tan 6 can be taken equal to tan 0 (from soil test report) A,= Area of pile.
ZONING OF KCC AREA
General
METROPOLITAN AREA T'
The layer is 10 ft thick and lies between 15 ft and 25 ft deep. There is a thick layer of sand between the depth of 40 ft to the looft depth, but it is not available in the entire Rayermohal area. The organic layer is also present throughout the area and the thickness of the layer is 5 ft to 25 ft.
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The soil characteristics at Daulatpur were shown to have no sand layer up to 125 ft depth from the natural ground level. At Rayermohal the subsoil contains mainly silt up to a depth of 130 ft from the natural soil layer (see figure 3.5). From Bastuhara to (jazir bflita a layer tFncK sanu aeptn zu it to that) it exists between 4D It to /U it cleptfl.
Some areas of Rayermahal contain a thick layer of sand in the subsurface, depth 25 feet to 35 feet and it is found in between 55 feet to 100 feet depth. There is some clay and sand present in silt but the percentage of clay and sand is too little i.e. not more than 20%.
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The soil profile has been done for Zone —II from north west part of Khulna city to south part of Khulna city i.e. Khalishpur to Lobonchora. In this area the subsoil layer contains mainly silt from the natural ground level 50 ft deep.
KHULNA
The soil characteristics of Khalishpur were seen that predominantly silt & full sand layer exists. In some places predominantly silt started from natural ground level and in some places sand layer started .. parts sand layer started from ground level to 70 feet depth. In the places where this layer is present, it is found in between 10 feet to 25 feet and the Tnikken.) it to jud it.
The subsoil in this area mainly contains a silt layer, a sand layer and an organic layer.
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The thickness of the predominantly silt layer averages 40, and the sand layer is about 50 ft thick. The predominantly silt layer starts at the natural ground level and has an average depth of 50 ft.
FIELD TEST FOR PILE CAPACITY
Static Pile Load Test
- Brief of Static Pile Load Test
- Caring Capacity of Cast-in-situ Pile from Static Pile load Test
4 Static pile load test is one of the most common methods to determine the actual in-situ. From the load test frame, the hydraulic k applied the test load in a series of steps according to the test. Depending on the performance of the test pile, the results may also allow for project cost savings by allowing an increase in pile design load, a reduction in total pile iellgtn, ariu a quanuncauori ol capacity in uiuicuii or uniuiown son eonuuions.
Properly setting up the pile load test can take a significant amount of time and effort. The location of the pile load tests should be in the most critical area of the site, for example where the load-bearing layer is deepest or weakest. The most common type of pile load test to determine vertical load capacity is the simple compressive load test.
A load cell is used to measure the force applied to the top of the pile. As the load is applied to the pile, the deformation behavior of the pile is measured. The pile is often subjected to a vertical load that is at least twice the design value.
In most cases, the objective is not to break the pile or stress the pile until bearing capacity failure occurs, but rather to confirm that the design end-bearing parameters used for.
Pile Load TesL on a Pile at Bastuhara Bridge
- Pile Load Test on it Pile at Rayer Maitol Bridge
- Pile Load Test on a Pile at Mayur River Bridge
- Pile Load Tesi oii it Piie at. KU Library Buiidiiig
- Pile Load Tesi on it Pile at. Kiiuiiia Medieai College ICU
- Pile Load Test oii a Piie for a Buildiiig at Soiiuduiiga
After the load test was completed, the maximum settlement was found to be 16.87 mm and the net settlement was 10.575 mm. After completing the static test of the pile 1-d, the fnflnwinor 1ncd vi-r-om orncc cett1ement riirvp icz chwn in Fia 4 In The diameter of the pile citii was 1000 mm and length 48 m. After the load test was completed, the maximum settlement was found to be 5.76 mm and the net settlement was 3.13 mm.
After the load test was completed, the maximum settlement was found to be 13.23 mm and the net settlement was 8.35 mm. After the load test was completed, the maximum settlement was found to be 0.81 mm and the net adjustment was 0.56 mm. After completing the load test, the maximum settlement was found to be 13.81 mm and the net adjustment was 11.567 mm.
After completion of the load test, the maximum settlement was 11.5 mm and the net settlement was 9.8 mm. A taiigern is urawri OH tile ioau versus gross settlement curve to find out the ultimate bearing capacity of the pile. 1ed test the folinwin(y 1e vPr,jiq arnvz qpttlpmpnt iirvp iz hwn in Fio 4 77 nnd the.
After completion of the load test, the maximum settlement was found to be 14.105 mm and the net settlement was 10.65 mm.
PILE CAPACITY FROM EQUATIONS
Allowable Pile Capacity from Different Existing Equations
From the table, at a depth of 30 m, the minimum calculated load of 1659.16 kN is obtained using Janbus's equation for end bearing for cohesive and conesian soil, Lomlinson's equation (U metnoa) for skin iriction for conical soil &. Terzaghi's equation for the final equation (method) for skin or clay triction and Burland's 35 equation (method b) for skin. It was found that in most cases the bearing capacity is not the same at the same depth for different equations.
Skin trictric LnQ was predicted based on the Meyerhof equation for both cohesive and cohesionless soils. Comparison Arora Tomlinson Tomlinson . sand), Tomlinson sand), Tomlinson -. med for skin method) for skin 2 lower + lower .. friction for clay friction for clay skin skin for clay & for clay & .. amp; Burland & Burland friction) friction). The load-bearing capacity was determined at every 1.5 m pile depth based on several existing equations using soil parameters at the point of the mat. It turned out that in most cases the load-bearing capacity is not the same at the same depth for different comparisons.
Lncl-bearing anu SKintriction was precisea trom the Meyerhof equation for both cohesive and cohesive soils. Terzaghi equation for end bed(clay & . sand), Tomlinson equation )a method) tor skin friction for clay & Burland elution (b 40 method) for skin friction for sand 2500.0. LI --- . sand), Tomlinson equation (a method) for skin friction for clay & Burland equation (b method) for skin friction for sand.
Vasir'cpnijation for nd hparinp (rlav sand), Tomlinson equation (a method) for .. skiii ii i LUll JUL clay at Oul idIlU CquoLIUII LJ . method) for skin friction for sand.
Allowable Pile Cupat.1iy of a Pile mi Mayur river from
Equation equation (a equation (a equation (a equation (a . sane kena tena metnoo) ior metnoa) ior metnoo ior mctnoa ior tw 2 0 bearing + bearing ± skin friction skin friction skin friction for skin friction for .. skin skin for clay & for clay & clay & Burland clay & Burland friction) friction) Burland Burland equation (b equation (b. Hansen equation for end bearing (clay& . 1, for skin friction for clay & Burland equation) O method) for skin friction for sand Vasics equation for end bearing (clay and sand) Tomlinson fouling (an mpthnd for skin friction for clay and Burland.
Ailowabie File Capaeiiy of a File a KU Library Buikiiiig
Various existing equations are used to determine the allowable bearing capacity of a pile at. The bearing capacity was determined at every 1.5 m of pile depth from various existing equations using the soil parameters at that point. Arora hquatlon (end bearing + ckin frir-tino). clay & sand), Tomlinson equation (method) for skin friction for clay &.
Janus equation for end bearing (clay and sand), Tomlinson equation one method) for skin friction for clay & Burland equation (h method) for skin friction for sand --Terzaghi equation for end.
Allowable Pile Capacity of a Pile in Kiiuiiia Medical College 'CU
Allowable He Capacity of a Pile at Shun Shin Cement Factory, Lobonchora
& sand method) method) equation (an equation (a -I 0. end for skin-by-skin method) for method) for c.
Allowable Pile Capacity of a Pile at Sonadanga
Overview of permitted bearing capacity for in-situ piles. rent rent equation for equation for. skin skin method) for method) for o 0. rent + rent ~ . friction for friction for skin friction skin friction ' skin skin , , , for clay & for clay & I- . friction) friction). Burland Burland Burland Burland equation (b equation (b equation (b equation (b method) for method) for method) for method) for skin skin skin friction skin friction friti fer -" fl"- for sand to sand.
RESULTS AND DISCUSSIONS
General
Allowable Pile Capacities from Load Tests and Equations
A— Hansen's equation for end bearing (ciay&sand), Tomlinson's equation (method) for skin friction for clay & Burland's equation (method 13) for skin friction for sand. Vasic equation for end bearing (clay and sand), Tomlinson equation (method) for skin friction for clay & Burland equation (13 method) for skin friction for sand. K— - Janbu's equation for end bearing (clay and sand), Tomlinson's equation (method) for skin friction for clay & Burland's equation (method 13) for skin friction for sand.
Terzaghi equation for end bearings (clay and sand), Tomlinson equation (one method) for skin friction for clay and Burland equation (13 method) for skin friction for sand. 1 Estimated pile capacity versus actual pile capacity curve based on different comparisons at different places in Khulna city area.
CHAPTER7
CONCLUSIONS AND RECOMMENDATIONS
Conclusions
Recommendations
