Splicing is called for when pile lengths required are too long for trucking or driving in one piece with the available equipment, or if there is a headroom restriction. A pile may have one or more splices.
Driven Precast Concrete Pile – Construction, Applications, and Advantages
The splice should be capable of resisting stresses induced by driving, and service loads and conditions. Tensile stresses are highest when resistance to driving is low and tensile waves are reflected back up the pile. Moment capacity is particularly important in high seismic zones, in piles possibly subject to impact, and in difficult driving conditions. The ability of a splice to develop the strength of the pile, or a reasonable percentage of that strength, depends on close tolerance and proper procedures in making the splice.
Careless workmanship or improper field procedures can result in significant deviations from strength and behaviour levels desired.
Precast Concrete Foundations- Features and Advantages
Most of these types are illustrated below. Variations in construction with actual splices may be encountered. The sturdily-built, easy-to-install and cost-effective pile joint was developed by world leading piling specialists at Emeca Oy, in Finland. Owner, Michael R. Jahnigen, a pioneer in the American pile driving industry, was so impressed with this innovative European product he brought it to the USA.
These joints conform to the requirements of the International Building Code IBC and are manufactured in our automated, state of the art facility located in Laurel, Delaware, the first of its kind in the United States. Chapter Menu.
This method is rarely used in the US and Canada as it idles expensive field labor and equipment while the weld is performed. Dowel: holes are cast or field drilled into the top of the bottom pile section. The top pile segment with rebar dowels protruding meters from the end is guided into place and the grout or epoxy in the holes cures around the dowels. Although material cost is low, this method is infrequently used in the US and Canada as it requires that the pile top segment be held in place until the epoxy or grout cures.
It slides over the driven section and the top pile section is then lowered into it and driving resumes. The splice is relatively economical and easy to use, but has very little bending and no tensile capacity. Connector ring: a short length of pipe is cast onto each end of the usually square pile. A pipe pile splice is set on the driven section and the top pile segment is set into the sleeve. Intermittent fillet welds can be used to increase the limited tensile strength of the joint.
This splice has been used extensively on Bruns piles in the New Orleans area; these splices both in the mould and in the field are shown below.
WHAT ARE THE ADVANTAGES & DISADVANTAGES OF PRECAST CONCRETE PILES?
Mechanical: steel plates or castings with attached rebar anchors approximately 2 metres long are precast into the pile ends. Pro-prietary systems are predominant that utilize high-strength steel bars to lock machined plates together. The Sure-Lock mechanical splice is made for all sizes of piling including some cylindrical piles and can equal the pile in bending and tension capacities.
This splice is shown below. Post-tensioned: used in large diameter cylindrical piles. Multiple strand holes are cast longitudinally through the center of the concrete wall. After curing, the segments are aligned and strands are post-tensioned to hold the sections in one long pile section.
Wedge: This method is generally used with precast piles. An example of this is the Westpile, which utilizes a wedge driven on plates attached to the pile ends. This puts the connection at the corners to develop resistance at the extreme fibres. This is shown above.Sign Up to The Constructor to ask questions, answer questions, write articles, and connect with other people.
You will receive a link and will create a new password via email. Sorry, you do not have permission to ask a question, You must login to ask question. Become VIP Member. Precast concrete foundation construction is an off-site construction technique in which the foundation units are pre-engineered and manufactured in a controlled environment.
These units as are pre-engineered, their capacities or the limits are communicated with the purchaser to produce the desired unit. Some of the important features, advantages and disadvantages of pre-cast concrete foundations are explained briefly in this article.
The precast concrete foundation technique is very prominent today. The airtight and weather resistant property of these types of foundation makes it common. The design of the precast concrete foundation is performed by considering the following important parameters:. Once the foundation units are manufactured and bought to the construction site, they are installed on an undisturbed soil layer.
In the case of a precast pad foundation, the pad foundation unit is placed over a lean concrete layer that was already prepared. Over the pad foundation, a precast column is placed. The bent bars kept out of the column are inserted inside the foundation element as shown in figure 1. The column rebars are embedded inside the precast foundation by a final casting using concrete.
When the work is complete, the adjustment devices and arrangements are removed. In the above figure, the pad foundation is placed over a deep foundation like pile. The pile constructed can also be a precast structure or a pile constructed on-site.For Updates on the Pensacola Bay Bridge visit fdot. Skip to Standard Plans for Bridge Construction. Standard Plans for Road Construction.
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Concrete Pavement.Precast concrete piles are cast, cured and stored in a yard before they are installed in the field mostly by driving. Geotechnical-Material Engineer. To know more about me just visit AboutMe. Thanks for this informative blog.
Very nicely explained about the advantages and disadvantages of precast concrete piles. Few months back I hired Australian Piling Expert for my piling project. It was such a pleasure to work with them that I want to gain more knowledge on piling. Apart from noise pollution and vibration what other disadvantage s do driven piles have in a developed residential environment? Your email address will not be published. Notify me of follow-up comments via e-mail address.
Save my name, email, and website in this browser for the next time I comment. Notify me of follow-up comments by email. Notify me of new posts by email. Advantages of Precast Concrete Piles Reinforcement used in the pile is not liable to change its place or get disturbed The defects in pile can be easily identified after the removal of forms, and these defects such as presence of cavity or hole can be repaired before driving the pile.
The cost of manufacturing will be less, as a large number of piles are manufactured at a time. Precast concrete piles can be driven under water. If the subsoil water contains more sulphates, the concrete of cast in situ piles would not set. Thus precast concrete piles have added advantage in such a circumstance. Precast concrete piles are highly resistant to biological and chemical actions of the sub soil.
Better quality control can be implemented as compared to bored cast in situ piles. These piles can be constructed in various cross-sectional shapes such as circular, octagonal or square. Disadvantages of Precast Concrete Piles These piles are usually very heavy. So special equipments are required for handling and transportation. Sufficient care must be taken at the time of transportation, otherwise piles may break.
For embedding these piles in field heavy pile driving equipment is required. These piles are costly as extra reinforcement is required to bear handling and driving stresses. The length of the pile is restricted since it depends upon the transport facility. Once constructed, it is not possible to increase the length of the pile as per the site demand If the pile is found to be too long, during driving, it is difficult and uneconomical to cut.
Lost your password? Please enter your email address. You will receive a link and will create a new password via email. Sorry, you do not have permission to ask a question, You must login to ask question. Become VIP Member. Driven precast concrete piles are widely used because of their versatility and suitability for most ground conditions.
These piles can be used for the foundation of all types of engineering structures under nearly every soil condition. Driven precast concrete piles are particularly suited where the founding stratum is overlain by soft deposits and aggressive or contaminated soils.
Piles are manufactured in factories under high-quality control, and consist of segmental lengths of reinforced concrete sections of lengths between 3m and 15m with required or standard cross-section.
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Have an account? Sign In Now. Free Signup or Login to continue Reading Remember Me! Don't have account, Sign Up Here. Forgot Password Lost your password? VIP Subscription. Previous article. Next article. Related Articles. Leave a comment Cancel reply.Precast concrete is a construction product produced by casting concrete in a reusable mold or "form" which is then cured in a controlled environment, transported to the construction site and lifted into place " tilt up ".
In contrast, standard concrete is poured into site-specific forms and cured on site. Precast stone is distinguished from precast concrete using a fine aggregate in the mixture, so the final product approaches the appearance of naturally occurring rock or stone. More recently expanded polystyrene is being used as the cores to precast wall panels. This is lightweight and has better thermal insulation.
Precast is used within exterior and interior walls. By producing precast concrete in a controlled environment typically referred to as a precast plantthe precast concrete is afforded the opportunity to properly cure and be closely monitored by plant employees.
Precast Concrete Piles
Using a precast concrete system offers many potential advantages over onsite casting. Precast concrete production can be performed on ground level, which helps with safety throughout a project.
There is greater control over material quality and workmanship in a precast plant compared to a construction site. The forms used in a precast plant can be reused hundreds to thousands of times before they have to be replaced, often making it cheaper than onsite casting when looking at the cost per unit of formwork. There are many different types of precast concrete forming systems for architectural applications, differing in size, function, and cost.
Precast architectural panels are also used to clad all or part of a building facade or free-standing walls used for landscaping, soundproofingand security walls, and some can be prestressed concrete structural elements. Stormwater drainage, water and sewage pipes, and tunnels make use of precast concrete units. To complete the look of the four precast wall panel types — sandwich, plastered sandwich, inner layer and cladding panels — many surface finishes are available.
Standard cement is white or grey, though different colors can be added with pigments or paints. The color and size of aggregate can also affect the appearance and texture of concrete surfaces. The shape and surface of the precast concrete molds have an effect on the look: The mold can be made of timber, steel, plastic, rubber or fiberglass, each material giving a unique finish.
Ancient Roman builders made use of concrete and soon poured the material into moulds to build their complex network of aqueductsculvertsand tunnels. Modern uses for pre-cast technology include a variety of architectural and structural applications — including individual parts, or even entire building systems. In the modern world, precast panelled buildings were pioneered in LiverpoolEnglandin The process was invented by city engineer John Alexander Brodiea creative genius who also invented the idea of the football goal net.
The tram stables at Walton in Liverpool followed in The idea was not taken up extensively in Britain. However, it was adopted all over the world, particularly in Eastern Europe  and Scandinavia.Log In. I have read many of your threads, regarding the elimination of battered piles. The job I am looking at is located in an inner harbor, Baltimore. A combination of battered piles and vertical piles have been designed.
I believe the piles will be approximately 50' long and are typically 20"x20" prestressed, precast piles. I believe they extend through approximately 30' of water. At this point I have no geotechnical report. I am interested in the concept of eliminating the battered piles and allowing a more flexible structure.
It seems to me that the structure was designed in two parts I certainly could be wrong, but that is my hunch. At particular areas, many battered piles are specified, expansion joints, etc My question is, how do vertical piles typically behave in the redundency of small waves?
If the geo-tech recommended battered piles for the lateral stability, what could I say to initiate a possibly different recommendation? I believe I read a P-y analysis?? RE: Precast Pile connection to Pile cap mjohan, I haven't done any pre-cast pile cap before and cannot comment your first question properly. I do feel confused though. A precast pile is usually driven to a set and cannot always end up with the top of the pile at the exact level in the design.
By the time you cut off part of the pile the integration with a pre-cast cap must be problematic because a joint has to be achieved at the underside of the pile cap. Is it possible that you really mean cast in-situ cap? As far as driven piles are concerned the square section is more common because they are mass produced in a casting yard and a square formwork is a lot easier to fabricate than a round one, bearing in mind the piles can be prestressed in series during manufacture requiring the moulds easily installed in the correct position relative to the reinforcement.
I shall refrain from offering any comment on precast pile cap as I haven't done one before. Structurally I doubt one can achieve a full moment connection with a precast pile cap. A pile cap exists for providing a foundation for a column and the setting out position of the pile cap msut be dead accurate. People generally allow a pile, either driven or cast in-situ, to deviate from its design position by about to 3" or 75mm. I cannot imagine in my little mind how by stacking another big lump of precast concrete on top of them will give you the accuracy required for the column which by any standard must be within about an inch or 25mm from the designed position.
I must admit that battered piles are rare and few in between although they are fairly common for jetties and offshore work. I am surprised by Focht3 that they are not good for the seismic.
Does a battered pile not offer a higher lateral resistance than a vertical pile? Battered piles are so stiff - in comparison to plumb piles of the same design - that they can lead to a catastrophic failure of the pile cap. It's a pretty big deal, yet I find a lot of engineers geotechs and structurals have no idea that battered piles can be a real problem - I doubt the pile cap will be precast. Never seen one, and can imagine lots of construction difficulties.
Reminds me of the, "Maybe you can draw it, but you can't wish it into place" warning I received as a young engineer. Increasing the PCC piles to 24 inch widths will have a big impact on stiffness. And I would definitely use a p-y analysis to evaluate the piles. Don't forget to consider group action!
In your opinion, does 30 kips sound about right for the lateral load applied at the top of each pile? Not factored, no seismic reduction taken. Thirty kips may or may not be a reasonable load. I just don't know.