Description:FIELD OF THE INVENTION
The present invention relates to a system for bored cast concrete piles. More specifically, the present invention relates to a semi hollow bored cast in situ large diameter concrete piles.
BACKGROUND OF THE INVENTION
In the current scenario, most of the important bridges on rivers carrying both and railway loading resting on deep foundations due to large number of scourable strata, increasing traffic load data and challenging soil conditions such as soft clays, loose sands, and areas with underground voids or karst formations. There are primarily two types of deep foundations are adopted in India i.e., pile foundations and well foundations.
Well foundations have historically been favoured in India, particularly for river bridges, due to their robust resistance to scour. Their large size and depth provide significant stability against erosion. However, well foundations have certain limitations such as construction can be complex, time-consuming and can be very costly, especially in deep water situations due to limited working season available. Pile foundations can be adapted to a wide range of soil conditions, including cohesive, non-cohesive, and mixed soils. Pile foundations support heavy loads, effectively control settlement, ensuring structural stability and faster construction due to wide working season available for driving of piles. However, Pile foundations have certain limitations such as specialized equipment and expertise are required and during driving of piles, it can generate significant noise and vibrations. However, increasing modern equipment available in the market, noise and vibrations are decreased significantly. The choice between pile and well foundations depend heavily on site-specific conditions, including soil type, groundwater levels, and scour potential. Advances in pile technology have made pile foundations a viable alternative in many situations than well foundations.
Now days, increasing availability of modern pile driving equipment, expertise and limited time availability for project execution, large-diameter cast-in-situ concrete piles are preferred over normal-diameter piles, particularly in bridge construction where heavy loads and challenging soil conditions are common due to high load bearing capacity, suitability for challenging soil conditions, reduced settlement, increased lateral stability and requirement of fewer piles.
In conventional design and construction of cast in situ concrete piles, entire pile filled with solid concrete with steel reinforcement as the primary reinforcing material. There is need for pile foundation that is customized for reduce the cost of pile foundation and saves energy.
Thus, there is a need for the present invention to solve the above-mentioned drawbacks and provides an efficient solution to the above discussed problem.
OBJECTIVE OF THE INVENTION
The main objective of the present invention is to provide a deep foundation for river bridges where scour is predominant using semi hollow bored cast in situ large diameter concrete piles to increases the allowable vertical capacity of the pile.
Yet another objective of the present invention is to is optimize the cost of foundation compared with conventional well foundation.
Yet another objective of the present invention is to avoid the tilt and shift problem that occurs during well foundation construction and optimized the construction time.
Yet another objective of the present invention is to save energy due to material saving.
Further objectives, advantages, and features of the present invention will become apparent from the detailed description provided herein below, in which various embodiments of the disclosed invention are illustrated by way of example.
SUMMARY OF THE INVENTION
The present invention relates to a system for semi hollow bored cast in situ large diameter concrete piles. The present invention includes a reinforcement cage. The reinforcement cage includes a concrete pile. The concrete pile includes a bottom solid concrete segment, a hollow segment and a top solid concrete segment. The bottom solid concrete segment extends from the foundation level of the concrete pile up to a definite height. The hollow segment which extends up to a definite height above the bottom solid concrete segment includes a circular steel liner and a steel plate. The circular steel liner is positioned concentrically inside the hollow segment and extends over the same height as that of the hollow segment. The steel plate which is welded at the bottom and the top of the circular steel liner acts as a separation between the hollow segment of the concrete pile and the solid part of the concrete pile. The top solid concrete segment extends from the cut-off level of the concrete pile towards downward by a depth equal to the sum of fixity length of the concrete pile and additional height. The incorporation of the hollow segment in the concrete pile of the system promotes efficient material utilization, reduces the overall cost of the system and promotes energy conservation while setting up of the system.
The main advantage of the present invention is that there is a reduction in the weight of pile, thus allowable vertical capacity of pile is increased compared with conventional bored cast in situ piles.
Yet another advantage of the present invention is that the present invention is cost effective in comparison with traditional well foundations adopted in river bridges.
Yet another advantage of the present invention is that the present invention allows faster construction compared with traditional well foundations.
Yet another advantage of the present invention is that the tilt and shifting problem are better manageable in the present invention than the traditional well foundations.
Yet another advantage of the present invention is that the present invention minimizes the impact on the existing structure by reducing pressure bulb infringement while ensuring adequate load-bearing capacity and structural stability, hence enabling the construction of proposed bridge adjacent to an existing bridge with a well foundation where sufficient space is unavailable.
Yet another advantage of the present invention is that less material is consumed by the present invention so that energy is saved.
Further objectives, advantages, and features of the present invention will become apparent from the detailed description provided herein below, in which various embodiments of the disclosed invention are illustrated by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are incorporated in and constitute a part of this specification to provide a further understanding of the invention. The drawings illustrate one embodiment of the invention and together with the description, serve to explain the principles of the invention.
Fig.1 illustrates the mid-section of the system.
Fig.2 illustrates an elevation view of the system.
Fig.3 illustrates comparison between bending moment diagrams of solid pile and semi hollow pile.
Fig.4 illustrates steel plate welded at bottom and top of circular steel liner acting as separation between solid and hollow portion of concrete pile.
DETAILED DESCRIPTION OF THE INVENTION
Definition
The terms “a” or “an”, as used herein, are defined as one or as more than one. The term “plurality”, as used herein, is defined as two as or more than two. The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open language). The term “coupled”, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
The term “comprising” is not intended to limit inventions to only claiming the present invention with such comprising language. Any invention using the term comprising could be separated into one or more claims using “consisting of” or “consisting of” claim language and is so intended. The term “comprising” is used interchangeably used by the terms “having” or “containing”.
Reference throughout this document to “one embodiment”, “certain embodiments”, “an embodiment”, “another embodiment”, and “yet another embodiment” or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics are combined in any suitable manner in one or more embodiments without limitation.
The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C” means any of the following: “A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.
As used herein, the term "one or more" generally refers to, but not limited to, singular as well as the plural form of the term.
The drawings featured in the figures are to illustrate certain convenient embodiments of the present invention and are not to be considered as a limitation to that. The term "means" preceding a present participle of an operation indicates the desired function for which there is one or more embodiments, i.e., one or more methods, devices, or apparatuses for achieving the desired function and that one skilled in the art could select from these or their equivalent in view of the disclosure herein and use of the term "means" is not intended to be limiting.
Fig.1 illustrates the mid-section of the system (100). The present invention relates to a system (100) for semi hollow bored cast in situ large diameter concrete piles. The present invention includes a reinforcement cage (110). The reinforcement cage (110) includes a concrete pile (102). The concrete pile (102) includes a hollow segment (106). The hollow segment (106) which extends up to a definite height includes a circular steel liner (108). The circular steel liner (108) is positioned concentrically inside the hollow segment (106) and extends over the same height as that of the hollow segment (106).
Fig.2 illustrates an elevation view of the system (100). The present invention relates to a system (100) for semi hollow bored cast in situ large diameter concrete piles. The present invention includes a reinforcement cage (110). The reinforcement cage (110) includes a concrete pile (102). The concrete pile (102) includes a bottom solid concrete segment (104), a hollow segment (106) and a top solid concrete segment (114). The bottom solid concrete segment (104) extends from the foundation level of the concrete pile (102) up to a definite height. The hollow segment (106) which extends up to a definite height above the bottom solid concrete segment (104) includes a circular steel liner (108). The circular steel liner (108) is positioned concentrically inside the hollow segment (106) and extends over the same height as that of the hollow segment (106). The top solid concrete segment (114) extends from the cut-off level of the concrete pile (102) towards downward by a depth equal to the sum of fixity length of the concrete pile (102) and additional height.
Fig.3 illustrates comparison between bending moment diagrams of solid pile and semi hollow pile. The results indicate that the bending moment distribution in the semi-hollow pile closely matches that of the solid pile below the fixity level, demonstrating similar flexural behaviour. Furthermore, in regions where the pile primarily functions as an axial member (i.e., where bending moments approach zero), the pile section can be made hollow without compromising structural performance. This approach promotes efficient material utilization and results in a significant reduction in pile weight.
Fig.4 illustrates steel plate (112) welded at bottom and top of circular steel liner (108) acting as separation between solid and hollow portion of concrete pile.
The present invention relates to a system for semi hollow bored cast in situ large diameter concrete piles. The present invention includes a reinforcement cage. The reinforcement cage includes a concrete pile. The concrete pile includes a bottom solid concrete segment, a hollow segment and a top solid concrete segment. The bottom solid concrete segment extends from the foundation level of the concrete pile up to a definite height. The hollow segment which extends up to a definite height above the bottom solid concrete segment includes a circular steel liner and a steel plate. In an embodiment, the hollow segment of the concrete pile is provided with a thick concrete wall to provide the system with structural integrity. The circular steel liner is positioned concentrically inside the hollow segment and extends over the same height as that of the hollow segment. In an embodiment, the reinforcement cage and the circular steel liner are lowered as a single prefabricated unit using cranes into the bored hole without any separate arrangement hence simplifying the installation. The steel plate which is welded at the bottom and the top of the circular steel liner acts as a separation between the hollow segment of the concrete pile and the solid part of the concrete pile. In an embodiment, the reinforcement cage, the circular steel liner and the steel plate are made of steel. The top solid concrete segment extends from the cut-off level of the concrete pile towards downward by a depth equal to the sum of fixity length of the concrete pile and additional height. In an embodiment, the incorporation of the hollow segment in the concrete pile of the system does not lead to any reduction on skin frictional resistance of system since the skin frictional resistance of system depends on the circumference length of concrete pile. In an embodiment, concrete is filled up to depth of fixity level of the concrete pile and extra one times of diameter of concrete pile from the cutoff level of the concrete pile to maintain and overcome the reduction in the stiffness factor of the concrete pile of the system. The incorporation of the hollow segment in the concrete pile of the system formed by the circular steel liner and capped by the steel plates reduces the self-weight of the system while enhancing vertical load capacity of the system without compromising structural integrity of the system. The incorporation of the hollow segment in the concrete pile of the system promotes efficient material utilization, reduces the overall cost of the system and promotes energy conservation while setting up of the system.
In an embodiment, the present invention relates to a method for constructing the system of semi-hollow bored cast in situ circular concrete pile, the method includes:
drilling a borehole to the required depth using rotary drilling rig or auger drilling equipment maintaining vertical alignment;
stabilizing the drilled borehole using temporary casing or drilling fluids (bentonite or polymer slurry) to prevent borehole collapse in loose soils;
after the required depth has been achieved, all loose soil, debris and slurry is removed from the drilled borehole using flushing techniques;
fabricating the reinforcement cage with the circular steel liner inside the hollow segment of the concrete pile;
lowering the reinforcement cage with the circular steel liner inside the hollow segment of the concrete pile into the borehole as a single unit using cranes;
pouring concrete and ensuring concrete fills the borehole;
the temporary casing is withdrawn gradually while concreting to prevent voids if the temporary casing has been used and if the permanent casing is required, the temporary casing is left in place;
after the concrete is hardened (typically 24-48 hours), excess pile head concrete is chipped to the required cut-off level and the exposed head of the concrete pile is cured using water or curing compounds for at least 7 days.
In an embodiment, proper concrete cover is maintained using spacers to ensure correct concrete cover around the reinforcement cage, using of tremie pipes for underwater concreting or direct pouring of the concrete is done if the borehole is dry, concrete is continuously poured over the bottom of concrete pile to avoid segregation or cold joints and proper concrete slump (typically 150-180 mm) is maintained to ensure flowability. In an embodiment, pile integrity test (PIT) or dynamic load test is conducted to assess structural soundness of the system and static/dynamic load tests is performed if required in project requirements. In an embodiment, concrete plug with diameter one times the diameter of bottom solid concrete segment is used to mobilize end bearing resistance. , C , Claims:I/WE CLAIM
1. A system (100) for semi hollow bored cast in situ large diameter concrete piles, the system (100) comprising:
a reinforcement cage (110), the reinforcement cage (110) having
a concrete pile (102), the concrete pile (102) having
a bottom solid concrete segment (104), the bottom solid concrete segment (104) extends from the foundation level of the concrete pile (102) up to a definite height,
a hollow segment (106), the hollow segment (106) extends up to a definite height above the bottom solid concrete segment (104), the hollow segment (106) having
a circular steel liner (108), the circular steel liner (108) is positioned concentrically inside the hollow segment (106) and extends over the same height as that of the hollow segment (106),
a steel plate (112), the steel plate (112) is welded at the bottom and the top of the circular steel liner (108), the steel plate (112) acts as a separation between the hollow segment (106) of the concrete pile (102) and the solid part of the concrete pile (102),
a top solid concrete segment (114), the top solid concrete segment (114) extends from the cut-off level of the concrete pile (102) towards downward by a depth equal to the sum of fixity length of the concrete pile (102) and additional height;

characterize in that, the incorporation of the hollow segment (106) in the concrete pile (102) of the system (100) formed by the circular steel liner (108) and capped by the steel plates (114) reduces the self-weight of the system (100) while enhancing vertical load capacity of the system (100) without compromising structural integrity of the system (100),
characterize in that, the incorporation of the hollow segment (106) in the concrete pile (102) of the system (100) promotes efficient material utilization, reduces the overall cost of the system (100) and promotes energy conservation while setting up of the system (100).
2. The system (100) as claimed in claim 1, wherein the hollow segment (106) of the concrete pile (102) is provided with a thick concrete wall to provide the system (100) with structural integrity.
3. The system (100) as claimed in claim 1, wherein the reinforcement cage (110) and the circular steel liner (108) are lowered as a single prefabricated unit using cranes into the bored hole without any separate arrangement hence simplifying the installation.
4. The system (100) as claimed in claim 1, wherein the incorporation of the hollow segment (106) in the concrete pile (102) of the system (100) does not lead to any reduction on skin frictional resistance of system (100) since the skin frictional resistance of system (100) depends on the circumference length of concrete pile (102).
5. The system (100) as claimed in claim 1, wherein concrete is filled up to depth of fixity level of the concrete pile (102) and extra one times of diameter of concrete pile (102) from the cutoff level of the concrete pile (102) to maintain and overcome the reduction in the stiffness factor of the concrete pile (102) of the system (100).
6. The system (100) as claimed in claim 1, wherein the reinforcement cage (110), the circular steel liner (108) and the steel plate (112) are made of steel.
7. The system (100) as claimed in claim 1, wherein concrete plug with diameter one times the diameter of bottom solid concrete segment (104) is used to mobilize end bearing resistance.
8. A method for constructing the system (100) of semi-hollow bored cast in situ circular concrete pile as claimed in claim 1, the method comprising:
drilling a borehole to the required depth using rotary drilling rig or auger drilling equipment maintaining vertical alignment;
stabilizing the drilled borehole using temporary casing or drilling fluids (bentonite or polymer slurry) to prevent borehole collapse in loose soils;
after the required depth has been achieved, all loose soil, debris and slurry is removed from the drilled borehole using flushing techniques;
fabricating the reinforcement cage (110) with the circular steel liner (108) inside the hollow segment (106) of the concrete pile (102);
lowering the reinforcement cage (110) with the circular steel liner (108) inside the hollow segment (106) of the concrete pile (102) into the borehole as a single unit using cranes;
pouring concrete and ensuring concrete fills the borehole;
the temporary casing is withdrawn gradually while concreting to prevent voids if the temporary casing has been used and if the permanent casing is required, the temporary casing is left in place;
after the concrete is hardened (typically 24-48 hours), excess pile head concrete is chipped to the required cut-off level and the exposed head of the concrete pile (102) is cured using water or curing compounds for at least 7 days.
9. The method as claimed in claim 8, wherein proper concrete cover is maintained using spacers to ensure correct concrete cover around the reinforcement cage (110), using of tremie pipes for underwater concreting or direct pouring of the concrete is done if the borehole is dry, concrete is continuously poured over the bottom of concrete pile (102) to avoid segregation or cold joints and proper concrete slump (typically 150-180 mm) is maintained to ensure flowability.
10. The method as claimed in claim 8, wherein pile integrity test (PIT) or dynamic load test is conducted to assess structural soundness of the system (100) and static/dynamic load tests is performed if required in project requirements.