Civil Engineering Industrial Training Report (Piling and Road)

Civil Engineering Industrial Training Report

(12 weeks of training experience in Piling)

Abstract As a part of the curriculum, and for the partial fulfillment of the requirements for completion of the Bsc Engineering degree from Sri Lanka Institute Of Information Technology, I, M.J.R.Fernando, underwent an industrial training at the Ralic Engineering, Kirindiwela Bridge site for 12 weeks during the months October 2015 -January, 2016. The report consist of brief study and description of materials,Equipments and procedures used at the site for construction. The report contains Three chapters in which I try to explain my 12 weeks experience in the hosting company. The content of all chapters is broadly explained and it is constructed from the practical basis of the site works ended all months. In the opening chapter I give details to the company background including its mission.so,it is give details of the company in terms of reader can easily know and access the company The second chapter is the most hunted chapter which explains my overall internship familiarity in the last successive months.This chapter is the main chapter and I record on it the overall work I have been executing.

Acknowledgement I am very thankful to Ralic Engineering (Pvt) Ltd for giving me the opportunity to undertake my12 weeks of training in their working area.Especially my humble thanks and regards are mentioned to our Industrial Training coordinator Mr.Sirisena and the departmental Advisor of Civil Engineering Dr.R.R.Perera and also I would like to convey my heartiest thanks to resident engineer Mr. Gayan Sanjaya and all stuff member works in Kirindiwela Bridge site. After my 12 weeks of training in Ralic Engineering (Pvt) Ltd, I feel that I am very confident in performig duties successfully in my future career in any establishment. I believe that it has given me a good knowledge and experience about how to engineering in practice in the real field. In my training period I have learnt about labor handling, project management techniques and how to manage and solve a problems

1.0)

Introduction

Vision To be Sri Lanka’s premier construction service provider.

Mission To provide a quality professional service, exceeding customer expectations, by the effective utilisation of all resources, with the best practice of the industry.

Services     

Site Planning & Evaluation Mini Hydro projects estimating Grading & Earthwork Analysis Hydrology & Hydraulic Modeling of Floodplains Site Demolition Plans

Company Structure

Company Organization flow chart

2.0)

Training Experience in Kirindiwela 9/3 Bridge

Client/Consultant :- Road Development Authority –Sri Lanka

Contractor :- Ralic Engineering (Pvt) Ltd

Project Location

Construction of the By-pass road

Definition of the By-pass road A bypass is a road or highway that avoids or "bypasses" a built-up area, town, or village, to let through traffic flow without interference from local traffic, to reduce congestion in the built-up area, and to improve road safety.

Soil compaction from the 8 ton roller

Laying of CP30 tar to the By-pass road

Plan view of existing bridge and By-pass road

Construction of Piles

Concrete Works

Concrete is a artificial stone composed of cement, sand and metal which sufficient water is added some times admixtures are used to improve the properties of the concrete. The primary operations of concreting are,     

Batching Mixing Transporting Placing Curing

Batching of concrete Batching is a process for measuring quantities of cement, fine aggregate, coarse aggregate and water etc, and mixing it to the correct proportion, correct method should be used for batching ingredients of concrete. There are two types of batching method  

Volume batching method Weight batching method

Mixing of concrete The cement, sand and aggregates are mixed thoroughly such that the in gredients are uniformly distributed in the concrete mass. There are two types of concrete mixing namely

 

Hand Mixing. Machine Mixing

Transport of concrete The concrete is laid in its intended place as soon as possible after mixing, and not more than 40 minutes should be aloud the times of first wettings and of lying in its place. In the work site the transportation was done by using dumpers, wheelbarrows, steel pans. Truck mixtures are used to transport ready mix concrete to site and hoist and pumping machine are used to transport concrete to upper floors and where truck mixtures can’t reach easily. Wheel barrows and dumpers are used for handling small quantity of concrete and over short distance

The dumper provides the middle range of capacity (usually 0.5-2.0m3) and it Suitable and medium haul lengths. Truck mixer capacities vary with different modes. They are1m3,2.5m3,3.0m3,3.5m3,5.00m3&7.00m3

Sample of C30 piling concrete

Grade of concrete

The grade of concrete canbe defined as a compressive strength of concrete. This is measured in N/mm2 Concrete can be prepared On weight basis or volume basis in different strength. In our site, concrete mix was Prepared on weight basis Grade 30 piling Concrete Cement – 400kg/m3 Water – 140kg/m3 Fine Aggregate – 642kg/m3 Course Aggregate – 1165kg/m3

Generel Details Concrete Grade – C30 Design slump 200+/_ 20 mm Cement type – Holcim Extra (PPC) Structural Element – In-situ Bored piles Batching Plant – ELS Ready mix ,Bemmulla

Tests for concrete Slump Test This test was done to determine the consistency of fresh concrete and to check its uniformity from batch to batch. Apparatus to conduct these tests are A Standard Slump Cone 300mm heights with a bottom diameter of 200mm and a top diameter of 100mm    

A ruler. A Steel tamping rod16mm diameter 600mm long. A small scoop. A waterproof base plate about 450mm Square.

Procedure of concrete slump test done at the site

1. The two foot pieces of cone were kept to hold it firmly in place during Steps 1 through 4. Cone mold was filled 1/3 full by volume with the concrete sample and it was kept for rodwith 25 strokes using a round, straight steel rod 2. Cone was filled 2/3 fully by volume (half the height) and again it was kept for 25 times with rod. 3. Cone was filled to overflowing and again it was kept for 25 times rod with rod just penetrating into, but not through, the second layer. Again strokes were distributed evenly. 4. Excess concrete was stroked off from top of cone with the steel rod so the cone was exactly level full. The overflow was cleaned away from the base of the cone mold. 5. Immediately after completion of Step 4, the operation of raising the mold was performed. 6. The steel rod was placed horizontally across the inverted mold so the rod was extended over the slumped concrete. Immediately the distance from bottom of the steel rod to the original center of the top of the specimen was measured. This distance, to the nearest 6 mm, was the slump of the concrete.

Cube Test This test was done to know the concrete compressive strength. For this purpose, either concrete cube or cylinder specimens are tested in the laboratory. In our site cube was used. Three concrete specimens were made and cured for 7, 14, 28 days at site and then sent to laboratory for testing

By this single test one judge that whether Concreting has been done properly or not. For cube test two types of specimens either cubes of 15 cm X 15 cm X 15 cm or 10cm X 10 cm x 10 cm depending upon the size of aggregate are used. At the site, cubical moulds of size 15 cm x 15cm x 15 cm are used. This concrete is poured in the mould and tempered properly so as not to have any voids. After 24 hours these moulds are removed and test specimens are put in water for curing. The top surface of these specimen should be made even and smooth. This is done by putting cement paste and spreading smoothly on whole area of specimen. These specimens are tested by compression testing machine after 7 days curing or 28 days curing. Load should be applied gradually at the rate of 140 kg/cm2 per minute till the Specimens fails. Load at the failure divided by area of specimen gives the compressive strength of concrete.

Steel Reinforcement details of the bridge foundation

Procedure of piling

Piles can either be driven into the ground (driven piles) or be installed in a predrilled hole (bored piles or drilled shafts). The construction of bore cast in situ concrete pile consists of 4 primary phases

1.Pile boring, 2.Reinforcement cage lowering, 3.Flushing 4.Pile concreting.

Pile boring 1. manually operable hammer should be mobilized at the required location 2. Four reference points (making two lines perpendicular to each other) should be marked for 3. 4. 5.

6.

7.

8.

checking centre of pile bore during boring of pile. Initial boring of about 1.5 meters is to be done using cutting tool The temporary guide casing, 1.5 meter length with outside diameter 900mm then lowered in the bore hole Position / centerline of the guide casing pipe with reference to pile reference points already fixed around the pile location shall be checked to shift/adjust the casing pipe to ensure proceeding of drilling at exact pile location without any deviation. Boring has to be done up to the founding strata as per drawings/ pre decided depth using intermittently bentonite slurry as per requirement. In case of requirement the bore hole is then supplied with bentonite slurry, from bentonite installation. Bentonite circulation channel will be made from bore hole to bentonite tank and fresh bentonite slurry will be pumped to bore hole through hose pipes. 24 hours prior to start of pile boring, ensure that bentonite is completely dispersed I the water and attains required density to stabilize the sides of bore hole during drilling. Bentonite slurry of specified quality should be circulated continuously during boring process Bentonite slurry is pumped by high pressure reciprocating pumps/ vertical pump into the bore hole and the same is allowed to overflow the bore hole. The overflow slurry with bored mud/soil etc that comes out along with bentonite slurry is passed through channels and is collected in sediment tanks where sediments settle and bentonite can be re used. Depth of pile shall be checked with sounding chain and exact depth shall be recorded in the pile report at the end of each hour.

Pile machine

Boring hammer

Reinforcement Cage Lowering

1. Prefabricated reinforcement cage prepared as per the drawings and approved depths, is brought and kept near pile location while boring is in progress 2. After the reinforcement cage will be gently lifted and lowered by crane/manually into the bored hole. Necessary concrete cover will be obtained by using the circular cover blocks already made of the same strength as of pile. 3. If the reinforcement cage is very long i.e. not possible to handle in one lift, the cage will be lifted one by one and spot welded at the joints and then lowered inside the bored hole.

Reinforcement cage lowering

Reinforcement of a pile

Flushing

1. After cage lowering, 200 mm diameter tremie pipes in suitable lengths are to be lowered in the hole. The operation is done by lowering one tremie pipe after another and connecting them threading to maintain water tightness throughout its length till the gap between the pile base and Tremie is between75 – 100 mm. the tremie pipe is locked/supported from top to maintain the level and funnel is attached on top. 2. The tremie head to be provided to the tremie pipe for the flushing activity. The bore is flushed by fresh bentonite slurry through the tremie head. The pumping for flushing is done by use of mud circulation pump. Flushing will be done to remove all the loose sediments which might have accumulated on the founding strata. Further, the flushing operation shall be continued till the consistency of inflowing and out flowing slurry is similar.

Pile Concreting 1. The concrete placing shall not proceed if density of fluid near about the bottom of 2. 3. 4. 5.

6.

7.

8. 9.

borehole exceeds 1250 kg/m3. After flushing is completed, tremie head should be removed and funnel should be attached to the tremie pipe. The slump of the concrete will be maintained at 180 mm to 220 mm Concreting operation will be carried out using the 200 mm diameter trmie pipes. Initial charge of concrete should be given in the funnel using a plug. Total concrete quantity in the funnel should be more than the volume of the entire pipe plus free space below the tremie. This will ensure a water tight concrete pouring through tremie. Lifting and lowering is repeated keeping sufficient concrete in funnel all the time. As the concreting proceeds the tremie pipe are to be removed one by one, taking care that the tremie pipe has sufficient embedment in the concrete until the whole pipe is concreted. Sufficient head of green concrete shall be maintained to prevent inflow of soil or water in to concrete. Placing of concrete shall be a continuous process from the toe level to top of pile. The concrete is poured in the funnel. As the concrete reaches the top of the funnel, the plug is lifted up to allow the concrete to flow corresponding to the placing of each batch of concrete. The concreting of pile is to be done up to 1.5m above the cut off level to get good and sound concrete at cut off level. After completion of concreting tremie, funnel and other accessories are to be washed properly and kept greased in proper stacking condition near next pile location.

Concreting of a pile

Tests done at the site before concreting a pile

1. Funnel Viscosity test 2. Mud density test 3. Sand content test

Funnel Viscosity Test

It is time, in seconds for one quart of mud to flow through a Marsh funnel which has a capacity of 946 cm3 . A quart of water exits the funnel in 26 seconds. This is not a true viscosity, but serves as a qualitative measure of how thick the mud sample is. The funnel viscosity is useful only for relative comparisons.

Determining the viscosity of a bentonite

Mud density Test

The mud density test was conducted using a mud balance, which consists of a base and a balance arm with cup, lid, knife edge, rider, level glass, and counterweight. The cup was attached to one end of the balance arm and the counterweight was at the opposite end.

Procedure of the density test The balance arm was placed on the base and the cup of the balance was completely filled with a sample of mud and the lid was placed firmly on top. then the rider was adjusted until the arm was level and the relative density was recorded

Mud balance used at the site

Sand Content test By definition, solid particles larger than 74 microns (200 mesh) are classified as API sand [one micron (m) = 10-6m]. These particles can be highly abrasive, and can cause excessive wear on pump parts, drill bits, and pipe connections. Excessive sand may also result in the deposition of a thick filter cake on the borehole wall, or it may settle in the hole around the tools when circulation is stopped. The sand content set consists of a 200-mesh sieve, a funnel, and a glass measuring tube calibrated from 0 to 20% to directly read the percentage of sand by volume.

Test Procedure 1. 2. 3. 4. 5.

Pour the sample into the sand content tube until it fills up to the mark labeled "Mud to Here." Add water to the mark labeled "Water to Here." Add oil instead of water when testing oilbase mud. Cover the mouth of the tube and shake vigorously. Pour this mixture through the screen. Add more clear water (or oil, for oil-base mud) to the tube, shake, and pour it through the same screen.

6. Gently wash the sand retained on the screen with a stream of water (or oil, for oil-base mud) to remove all mud and shale particles.Gently wash the sand retained on the screen with a stream of water (or oil, for oil-base mud) to remove all mud and shale particles. 7. Fit the funnel upside-down over the top of the screen. 8. Turn the tip of the funnel into the mouth of the washed tube. 9. Wash the sand back into the tube with water (or oil with oil-base mud) applied to the back of the screen. 10. Allow the sand to settle in the tube and read the volume percent of sand

Pouring the mud and water mixture through the screen.

References     

http://www.wipertrip.com/drilling-fluids/testing/372-sand-content-mud-testing.html http://www.wipertrip.com/drilling-fluids/testing/376-funnel-viscosity-mud-testing.html http://ralic.lk/ http://www.aboutcivil.org/concrete-slump-test.html http://www.bentonite.com/bpm/default.page