PILE FOUNDATIONS. This layer cannot support the weight of the building, so the loads of the building have to bypass this layer and be transferred to the layer of stronger soil or rock that is below the weak layer. When a building has very heavy, concentrated loads, such as in a high rise structure, bridge, or water tank.
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Shear, bond bearing,camber & deflection in prestressed concreteMAHFUZUR RAHMAN
This Presentation was presented as a partial fulfillment of Prestressed Concrete Design Lab Course. Behavior & Design of Prestress on above topic is shortly discussed on the presentation. The part "Shear & Shear Design in Prestressed" Concrete was prepared by me. Other topics were prepared by other members of my group. Thanks to all my teachers & friends who helped us in different stages during preparation of the total presentation.
this presentation describes in details the sinking operation of well foundations in different conditions and situations. the content here is suitable only for basic knowledge and educational purposes.
Shear, bond bearing,camber & deflection in prestressed concreteMAHFUZUR RAHMAN
This Presentation was presented as a partial fulfillment of Prestressed Concrete Design Lab Course. Behavior & Design of Prestress on above topic is shortly discussed on the presentation. The part "Shear & Shear Design in Prestressed" Concrete was prepared by me. Other topics were prepared by other members of my group. Thanks to all my teachers & friends who helped us in different stages during preparation of the total presentation.
this presentation describes in details the sinking operation of well foundations in different conditions and situations. the content here is suitable only for basic knowledge and educational purposes.
Grillage Analysis of T-Beam bridge, Box culvert and their Limit State Design; components of Bridges and loads acting on bridges are presented in this slide.
About foundation and its Types
1. Foundation, Part of a structural system that supports and anchors the superstructure of a building and transmits its loads directly to the earth.
2. To prevent damage from repeated freeze-thaw cycles, the bottom of the foundation must be below the frost line.
3. The foundations of low-rise residential buildings are nearly all supported on spread footings, wide bases (usually of concrete) that support walls or piers and distribute the load over a greater area.
4. A concrete grade beam supported by isolated footings, piers, or piles may be placed at ground level, especially in a building without a basement, to support the exterior wall.
Pile foundation is important for construction of foundation where bearing capacity of soil is poor. Pile foundation is use for distribution of uneven load of superstructure.There are so many type of pile are use for construction. Here i present some of pile with suitable condition for construction and methods for construction.
Thank you.
General Information of Retaining Walls about its type, design and functionality; This file does not comprise of detail study of the Retaining Walls but for a startup it may help students!!!
Pile foundation are essential in case where SBC is low or the load coming from superstructure is too heavy,
Topics covered includes Materials used for making piles, Type of piles, load transfer mechanism, factors affecting selection of piles, Installation methods, load carrying capacity of piles, different load tests performed and the behavior of piles as a group.
Grillage Analysis of T-Beam bridge, Box culvert and their Limit State Design; components of Bridges and loads acting on bridges are presented in this slide.
About foundation and its Types
1. Foundation, Part of a structural system that supports and anchors the superstructure of a building and transmits its loads directly to the earth.
2. To prevent damage from repeated freeze-thaw cycles, the bottom of the foundation must be below the frost line.
3. The foundations of low-rise residential buildings are nearly all supported on spread footings, wide bases (usually of concrete) that support walls or piers and distribute the load over a greater area.
4. A concrete grade beam supported by isolated footings, piers, or piles may be placed at ground level, especially in a building without a basement, to support the exterior wall.
Pile foundation is important for construction of foundation where bearing capacity of soil is poor. Pile foundation is use for distribution of uneven load of superstructure.There are so many type of pile are use for construction. Here i present some of pile with suitable condition for construction and methods for construction.
Thank you.
General Information of Retaining Walls about its type, design and functionality; This file does not comprise of detail study of the Retaining Walls but for a startup it may help students!!!
Pile foundation are essential in case where SBC is low or the load coming from superstructure is too heavy,
Topics covered includes Materials used for making piles, Type of piles, load transfer mechanism, factors affecting selection of piles, Installation methods, load carrying capacity of piles, different load tests performed and the behavior of piles as a group.
DEEP FOUNDATIONS - definition, when are they used, forms of construction, pile foundation - types, uses, applications, advantages and disadvantages, selection of type of piles, causes of failure, pile driving, cofferdams, types of cofferdams, caisson foundation ad its types and all the information regarding deep foundations.
Introduction, uses, selection of pile, types of piles, pile cap and pile
shoe, pile driving methods, micro piling, causes of failures of piles,
Heaving of piles
TYPES OF PILE FOUNDATION & APPLICATIONSMaharshi Dave
The PPT about pile foundation and types of pile foundation.It is very useful and make very properly.If you don't know about pile foundation then no problem only just refer this PPT and then you will become to know about pile foundation very well.I hope this will helpful to someone.
Underground Construction provides construction, technical and management services to its customers. The company specializes in power, communications, airport fueling and heavy engineering. Since laying its first pipe in 1936, Underground Construction has completed thousands of projects throughout the United States.
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Self-curing concrete is achieved by means of replacing a part of aggregate by lightweight aggregate or adding chemical admixtures. The self-curing process of concrete takes place from inside to outside, thus reducing the autogenous shrinkage and self-desiccation, especially for the high-performance concrete with relatively low water/binder ratio.
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Trenchless construction. Trenchless construction includes such construction methods as tunneling, microtunneling (MTM), horizontal directional drilling (HDD) also known as directional boring, pipe ramming (PR), pipe jacking (PJ), moling, horizontal auger boring (HAB) and other methods for the installation of pipelines and cables below the ground with minimal excavation.
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A stressed ribbon bridge (also stress-ribbon bridge or catenary bridge) is a tension structure (similar in many ways to a simple suspension bridge). The suspension cables are embedded in the deck which follows a catenary arc between supports. Unlike the simple span, the ribbon is stressed in traction, which adds to the stiffness of the structure (simple suspension spans tend to sway and bounce).
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The process of self-healing of cracks or self-filling up of cracks by the help of bacterial reaction in the concrete after hardening is known as Self-Healing Concrete. It can be observed that small cracks that occur in a structure of width in the range of 0.05 to 0.1mm gets completely sealed in repetitive dry and wet cycles.
The typical deflection diagrams shown in figures 1 and 2 indicate that all the high strength concrete beams had adequate ductility and Structural Behaviour of High Strength Concrete Beams 135 showed substantial deflections at failure. The ulti- mate deflections shown in Table 3 were measured prior to failure as near to collapse as possible.
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Autoclaved aerated concrete (AAC) is a lightweight, precast, foam concrete building material suitable for producing concrete masonry unit (CMU) like blocks. Composed of quartz sand , calcined gypsum , lime , cement , water and aluminum powder , AAC products are cured under heat and pressure in an autoclave .
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A submerged floating tunnel, also known as submerged floating tube bridge, suspended tunnel, or Archimedes bridge, is a proposed design for a tunnel that floats in water, supported by its buoyancy. The tube would be placed underwater, deep enough to avoid water traffic and weather, but not so deep that high water pressure needs to be dealt with—usually 20–50 m is sufficient. Cables either anchored to the Earth or to pontoons at the surface would prevent it from floating to the surface or ...
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The bundled tube structure meant that "buildings no longer need be boxlike in appearance: they could become sculpture." Hybrids. Hybrids include a varied category of structures where the basic concept of tube is used, and supplemented by other structural support(s).
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marble slurry dust as cement additive , The research on the use of marble dust in concrete , , disadvantages of marble dust and quarry dust additive in concrete; Chat Now; disadvantage of using quarry dust in concrete
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Computer Ethics: Ethics is a set of moral principles that govern the behavior of a group or individual. Therefore, computer ethics is set of moral principles that regulate the use of computers. Some common issues of computer ethics include intellectual property rights (such as copyrighted electronic content), privacy concerns, and how ...
CIVIL SEMINAR REPORT :USE OF GEOGRIDS IN FLEXIBLE PAVEMENT. Geogrids can also prevent aggregate penetration into the subgrade, depending on the ability of the geogrid to confine and prevent lateral displacement of the base/sub-base. However, the geogrid does not prevent intrusion of subgrade soils up into the base/sub-base course,...
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Courier management system project report.pdfKamal Acharya
It is now-a-days very important for the people to send or receive articles like imported furniture, electronic items, gifts, business goods and the like. People depend vastly on different transport systems which mostly use the manual way of receiving and delivering the articles. There is no way to track the articles till they are received and there is no way to let the customer know what happened in transit, once he booked some articles. In such a situation, we need a system which completely computerizes the cargo activities including time to time tracking of the articles sent. This need is fulfilled by Courier Management System software which is online software for the cargo management people that enables them to receive the goods from a source and send them to a required destination and track their status from time to time.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
2. INTRODUCTION
Pile foundation have been used for many years, for carrying and transferring
the loads to soil considered to be weak in structure due to the soil conditions.
In the early stages of development, villages and towns were located in the
close vicinity of lakes and rivers due to the availability of water , and, also, to
ensure proper protection of the area.
Therefore, the weak bearing ground was reinforced by the use of timber
piles that were manually forced into the ground, or fixed into the holes that
were filled with stones and sand.
The primitive methods of pile installation were modified after the industrial
revolution, and the techniques of installation by steam or diesel driven
machines were introduced.
With the advancement in the technologies of soil mechanics and other
related disciplines, superior piles and pile installation system have been
developed.
3. NECESSITY OF PILE FOUNDATION
A pile foundation is required to reduce differential settlement.
they are required for the transmission of structure loads to a firm stratum.
Pile foundations are used to resist horizontal forces in addition to support
the vertical loads in earth-retaining structures and tall structures that are
subjected to horizontal forces due to wind and earthquake.
Piles are required when the soil conditions are such that a washout,
erosion or scour of soil may occur from underneath a shallow foundation.
In case of expansive soil,they are used to transfer the load below the
active zone.
Piles are used to transfer the load beyond the zone of possible moisture
changes in such soils.
4. PILE FOUNDATION VS WELL FOUNDATION
Well foundations provide a solid and massive foundation for heavy loads as
against a cluster of piles which are slender and weak individually and are
liable to get damaged when hit by floating trees or boulder rolling in river
bed.
Wells provide a large section modulus with the minimum cross sectional
area and hence efficient in taking large vertical and horizontal loads even
when the unsupported length is large.
Concreting of well steining is done under dry and controlled conditions and
hence quality of work is assured, however same cannot hold good in case of
cast-in-situ bored piles where concreting is to be done under water or below
ground level. Even in case of precast piles, the concrete is subjected of
heavy stresses during driving operation and consequent damages cannot be
ruled out.
When scour takes place, the piles act as long struts and have to be
designed for buckling stresses, which are quite heavy due to the bending
moments contributed by the longitudinal forces on the bridge deck due to
5. It is difficult to drive the piles through the strata having boulders and tree
logs which are frequently encountered in alluvial soil, whereas in the case
of a well foundation there is sufficiently access to remove the obstruction.
Quite often the skin friction developed is of much magnitude as to prevent
further driving of a pile although a firm stratum has not been reached.
The adoption of pile foundations is advantageous over well foundations
where the soil characteristics and conditions of water table are such that
the phenomenon of blow occurs during dewatering of the well.
Increased mechanization and advent of new machinery have brought
down the cost of foundation with piles considerably low in comparison to
well. New testing techniques for checking the integrity of piles and
information about strata through piles have passed or resting have
removed the uncertainty of load carrying capacity of piles to large extent.
Pile foundations have a clear advantage over well foundations in terms of
speedy construction. Wherever time is the criterion, the pile foundation is
the natural choice.
6. TYPES OF PILE COSTRUCTION
Precast Driven Piles –These are usually of RCC or pre-stressed concrete
and generally small in size for ease in handling. The main advantage of this
type of pile is that its quality, in terms of dimension, use of reinforcement and
concrete, can be ensured as the piles are cast in a yard under controlled
conditions. care is needed while handling, transporting and driving the pile to
avoid damages.
Driven Cast-in-Situ Piles-A steel casing pile with a shoe at the bottom is
driven first to the required depth. The reinforcement cage for the pile is then
lowered inside the casing and the pile is concreted. These are not suitable
for use in soft soils, in greater depths or where keying with the rock is
required.
Bored cast-in-situ piles –In the bored cast-in-situ process, a larger diameter
casing is used. A casing of 3 to 4 m in length is provided on top of the bore
hole which is driven with the help of a bailor.
7. Driven steel piles –Steel piles can be circular or in other structural shapes.
The circular ones are made in the form of either welded or seamless piles.
Usually steel or cast iron piles used earlier for bridge structures are of longer
diameter and screw type. These were used in past when loading was less.
These piles are suitable for being driven through cohesive soil to reach up to
the hard strata and to serve as bearing piles. They are not suitable where
heavy scour is expected and for foundation for bridges when foundations are
situated wide apart.
Driven timer piles –Timber piles have been extensively used in America.
These have been used in India on the railways and highways, for temporary
bridges. Timber piles are of hard wood, and used in natural form with thin
end cut or suitably sized. They are used mostly as end-bearing piles in
clusters. They are normally used in lengths of 12m and extended by splicing
for use in deeper channels. The piles protruding above bed/low water level
are suitably braced in cluster.
8. FACTORS INFLUENCING CHOICE OF PILE:
Location and type of structure
Ground conditions
Durability
Cost
9. LOCATION AND TYPE OF STRUCTURE
For structures over water, such as wharves and jetties, driven piles or driven
cast-in- place piles (in which the shell remains in place) are the most
suitable. On land the choice is not so straight forward. Driven cast-in-place
types are usually the cheapest for moderate loadings. However, itis often
necessary for piles to be installed without causing any significant ground
heave or vibrations because of their proximity to existing structures. In such
cases, the bored cast-in-place pile is the most suitable. For heavy structures
exerting large foundation loads, large-diameter bored piles are usually the
most economical. Jacked piles are suitable for underpinning existing
structures.
GROUND CONDITIONS
Driven piles cannot be used economically in ground containing boulders, or
in clay when ground heave would be detrimental. Similarly, bored piles would
not be suitable in loose water-bearing sand, and under-reamed bases cannot
be used in cohesionless soils since they aresusceptible to collapse before
10. DURABILITY
This tends to affect the choice of material. For example, concrete
piles are usually used in marine conditions since steel piles are
susceptible to corrosion in such conditions and timber piles can be
attacked by boring molluscs. However, on land, concrete piles are
not always the best choice, especially where the soil contains
sulphates or other harmful substances.
COST
In coming to the final decision over the choice of pile, cost has
considerable importance. The overall cost of installing piles includes
the actual cost of the material, the times required for piling in the
construction plan, test loading, the cost of the engineer to oversee
installation and loading and the cost of organisation and overheads
incurred between the time of initial site clearance and the time when
construction of the superstructure can proceed.
11. UNDERREAMED PILES
Underreamed piles are bored cast-in-situ concrete piles having one or more
bulbs formed by enlarging the pile stem with a suitable cutting tool.
Enlarged base in the form of underream bulb made in the strata of good
bearing provides larger bearing area and piles of greater bearing capacity
can be constructed.
These piles have been extensively used in India to support a wide variety of
structures in almost all types of soil strata on the basis of safety and
economy.
Depending on these considerations these piles are being increasingly used
for a wide variety of structures, e.g., buildings both residential and industrial,
transmission line, TV, antenna and satellite tracking towers, tanks, over
bridges, machine foundations and dry docks etc.
The provision of bulbs is useful in two ways.
12.
13. It provides larger bearing area at greater depths which are more firm and stable. It
also serves as an anchor and keeps the foundation stable in the event of any upward
drag of the pile stem. The provision of more than one bulb along the stem further
improves the performance of the pile and the latter is then called multi-underreamed
pile. For selecting an appropriate underreamed pile the variables are pile length, stem
diameter and number of bulbs. A general configuration of underreamed piles and
typical details are shown in fig.
The safe load on underreamed piles, like any other bored piles, can be determined
from the static formulae using soil properties. These formulae give ultimate capacity
of pile and after applying a suitable factor of safety safe loads are determined. But
this approach is reliable only if correlations are locally established for a particular
area.
Qu = cNcAb +& c’As’
where,
Ab = area of enlarged base
Nc = 9
Adhesion factor & is 0.4. Another direct approach is to perform field load tests on
piles and determine safe load from the load-deflection curves. This approach for safe
loads is preferable but load tests require elaborate set up and are costly. In the
analysis developed herein, Finite Element Approach has been adopted to analyze
underreamed piles in various types of soils. In this method all the complexities of the
problems, like varying shape, boundary conditions and loads are maintained as they
14. CONCLUSION
Piles are often used because adequate bearing capacity cannot be found
at shallow enough depths to support the structural loads.
It is important to understand that piles get support from both end bearing
and skin friction.
The proportion of carrying capacity generated by either end bearing or
skin friction depends on the soil conditions. Piles can be used to support
various different types of structural loads.
15. REFERENCES
Tina Lai "Structural behavior of Pile Foundation and their applications
to lightweight bridge decks" ,M.Tech thesis, MIT, 2009.
Sergiu Cal in, Ciprian Asavoaie and N. Florea, "Issues for achieving
an experimental model" Bul. Inst. Polit. lai, t. LV (LIX), f. 3, 2009.
Martina Schnellenbach-Held and Karsten Pfeffer,"Punching behavior
of biaxial hollow slabs" Cement and Concrete Composites, Volume
24, Issue 6, Pages 551-556, December 2002.
Sergiu Calin, Roxana Glntu and Gabriela Dascalu, "Summary of tests
and studies done abroad on the Pile Foundation system", The
Buletinul Institutului Politehnic din lai, t. LV (LIX), f. 3, 2009.
Sergiu Calin and Ciprian Asavoaie, "Method for Pile Foundation
concrete slab with gaps", The Buletinul Institutului Politehnic din lai,
LV (LTX), f. 2,2009.