Pile foundation-substructure column system and construction method of the pile foundation-substructure column system

Description

TECHNICAL FIELD

The present invention relates to a continuous pile foundation-substructure column system, wherein the substructure column is extended from the pile utilizing the construction method of this pile foundation-substructure column system. In this pile foundation-substructure column system, the pile foundation-substructure column structures are organized into a certain shape, meeting the demands of load bearing as well as architecture and finished surface requirements.

The invention may be applied in civil construction areas such as foundation systems; basement columns in high-rise buildings or the foundation systems; columns, piers of bridges, jetties, whafts.

BACKGROUND ART

Definition:

Ground level (GL) is the nominal height conventionally implying surfaces with clear physical boundaries such as ground floor, bridge, deck, natural ground or water surface. In other words, ground level (GL) is the surface where either construction equipment, vehicles, people use during or after construction. In building construction, it is the floor of the ground floor, in bridge construction, its bridge deck. Ground level, thus, could be an existing physical surface like a yard, existing road but also could be a future surface, to be built, at predetermined height such as ground floor, bridge deck.

Pile foundation: It is the part that is built into the ground to support the load of the construction, in the form of piles using friction, end bearing or combination.

Substructure column: it's the vertical element connecting the structure at/just above ground level with pile foundation, directly or through pile cap systems, in building construction, it's basement column, in bridge construction, it's bridge pier.

Substructure system: It is the structure to connect foundation and the structure above ground level. In building construction, it is the pile cap and basement column, in bridge construction, it is the pile cap and bridge pier.

Underground surface: It is the physical surface that just above pile foundation, in building construction, it is the basement bottom floor, in bridge construction, it is at approximately the river bed.

Construction works, especially medium and big scaled ones, use a lot of pile foundation systems, wherein the piles are concrete piles, steel piles, precast or cast-in-situ, constructed by drilling, hammering or pressing. Such a system is usually constructed on the construction surface, e.g., ground surface for high-rise building, or water surface for bridges, conventionally connected by pile cap systems installed at contiguous areas of basement bottoms for high-rise buildings, riverbed for bridges, and connected pile foundation-substructure column systems for houses, jetties, whafts. This system of pile caps and columns are composed of cast-in-situ reinforced concrete constructed by formwork and cast-in-situ pumping system. This system is broadly used in civil construction works and infrastructure works and is the prevailing structure system for medium and large projects. The columns underground for high-rise building, or piers under water for bridges, shall hereinafter be called substructure columns, to distinguish from columns above ground floor or piers above the bridge deck which require different methods of construction.

The above system has the following shortcomings:

For pile caps in challenging locations such as basements of high-rise buildings, where the pile caps are built underground, or piers, where the pile caps are built at the riverbed, the process is time-consuming, expensive and safety is low due to difficult accessibility.

The use of formwork for construction of caps and columns necessitates the formation and protection of construction areas such as retaining walls or water cofferdams which are costly, time-consuming and risky in construction. These protection systems themselves require complicated construction methods to create.

To meet structural requirements, these works conventionally utilize piles with various diameters and depths which are difficult to modularize or optimize in terms of equipment, materials and load testing procedures.

There is therefore a need for a pile foundation-substructure column system to overcome the above issues while retaining the integrity of the said structure.

SUMMARY OF INVENTION

To overcome the above shortcomings, the present invention provides a continuous pile foundation-substructure column system without the use of pile caps to connect with the body or main structure of the construction work to save construction time, cost and increase construction safety.

The pile foundation-substructure column system provided by the invention includes:

• • the steel casing pipes (11) are stacked or aligned together with an interlocking system wherein the steel casing pipes (11) are slide guided with use of male-female (25, 26) slide rail system provided on the steel casing pipes. This system shall hereinafter referred to as the stack and slide system.
  • pile foundation-substructure column structures, wherein each pile foundation-substructure column structure is constructed along the inside of the steel casing (11), boreholes are created inside the steel casing pipes (11) by a predefined depth and filling the borehole and the casing pipe with a homogeneous material from the bottom of the borehole to approximately the ground level, wherein this material binds with the steel casing pipe (11) during the construction process.
  • connect the pile foundation-substructure column structures into a pile foundation-substructure column system wherein all these structures work together.

The present invention provides a method for constructing this pile foundation-substructure column system. This method comprises the following steps:

• • driving steel casing pipes (11) into the ground, which is below the ground level in parallel by such methods as vibrating, pressing or hammering, these steel casing pipes are driven into the ground in the stack and slide system; in one embodiment, the casing pipes are elevated at a approximate height within the range from the underground surface and the ground level;
  • drilling to take out the soil inside the steel casing pipes, with predefined diameter and depth;
  • create a pile foundation-substructure column structure along the inside of the steel casing (11), create a borehole inside the steel casing pipes (11) by a predefined depth and filling the bore hole and the casing pipe (11) with a homogeneous material from the bottom of the borehole to approximately the ground level, wherein this material binds with the steel casing pipe (11);
  • connecting the pile foundation-substructure column structures into a pile foundation-substructure column system wherein all these structures work together.

With the structure and method provided by the present invention, characterized by the homogeneity (continuity) of the pile and the substructure column (pile foundation-substructure column structure), the following advantages may be achieved:

• • it is no longer necessary to implement the pile cap system which is costly, time consuming and dangerous, due to difficult construction conditions such as underground or on the riverbed;
  • the substructure columns are finished as soon as the pile foundation are finished, whereby saving time and minimizing risks to substructure column construction (building basement columns, or the bridge piers);
  • all piles, columns and pile caps, which are usually complicated and different dimensions in each location of the construction work is organized into a system of one or few pile foundation-substructure column modules thereby optimizing and simplifying the processes of testing, checking and also standardizing equipment and material used.

Additionally, casing pipes are fixed to guarantee that pile foundation-substructure column structures are operationally bound together as a pile foundation-substructure column complex, thereby overcoming the issues pertaining load imbalance whereby some piles bear the load and some do not. This increases the actual safety factor of the foundation system.

The steel casing pipes are driven into the ground in the stack and slide system to guarantee uniformity and accuracy of location for the individual pile foundation-substructure column structures that constitute the pile foundation-substructure column system.

The steel casing pipes and the pile foundation-substructure column structures may be designed to form basic shapes such as triangles, crosses or letters I, L, T from a top-down view. Variable piles/column layouts meets loading capacity and optimise architectural requirements such as car parking for high rise building basements.

BRIEF DESCRIPTION OF DRAWINGS

Hereinafter, the advantages, objects and detailed structures following preferred embodiments of the invention will be described with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic view illustrating the pile foundation-substructure column system according to an embodiment of the invention;

FIGS. 2a, 2b is a schematic view illustrating (a) the sliding guide structure of casing pipes according to an embodiment of the invention; and (b) the sliding guide structure of casing pipes and method of binding them according to an embodiment of the invention;

FIGS. 3a-3e are schematic views illustrating various layouts of casing pipes according to various embodiments;

FIGS. 4a, 4b is a schematic view illustrating the pile foundation-substructure column system constituting a closed perimeter.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the preferred embodiments of the invention will be described.

As shown in FIG. 1, pile foundation-substructure column system includes multiple steel casing pipes 11 positioned parallel to each other. The pile foundation-substructure column structures 12 including piles and substructure columns are manufactured in a homogeneous manner (i.e., continuous) inserted inside each steel casing pipe 11. The steel casing pipes 11 are driven into the ground, in one embodiment, each of which elevates at a approximate height within the range from the underground surface to ground level.

The pile foundation-substructure column structure 12 including piles and substructure columns are manufactured inside, along the steel casing pipes 11, wherein the piles penetrate through the underground surface at a predefined depth and the substructure columns extend along the axis of the steel casing pipes 11.

The steel casing pipes 11 are partially driven into the ground through the underground surface in the manner of the stacking sliding system, in particular, the steel casing pipes include components to guide the sliding. The parallel sliding guide ensures the accuracy in positioning, and verticality in construction.

According to the embodiment illustrated in FIG. 2a, steel casing pipes are slide guided with the use of a male-female slide rail system that includes a male portion 26 sliding inside a female portion 25. These male and female portions are provided on steel casing pipes 11.

Another embodiment is illustrated in FIG. 2b, wherein each male portion 22 on each casing pipe slides within a female portion of the intermediate slide rail system 23 and is secured by the bolt 24. Additionally, the steel casing pipes 11 may be secured by welding it into one unitary piece.

Thereafter, the pile foundation-substructure column structures are bound together to bear the calculated loads during and/or after construction in order to guarantee that individual pile foundation-substructure column structures 12 are bound together to constitute a system of pile-column complex that bear equal loads thereby eliminating load imbalances where some piles bear the loads and some do not.

To bind the pile foundation-substructure column structures, it is possible to bind the steel casing pipes 11 or directly bind the pile foundation-substructure column structures. According to an embodiment, the casing pipes may be bound by bolts or welding.

According to another embodiment, the pile foundation-substructure column structures may be bound together and secured by the beam system provided on the head of the pile foundation-substructure column structures.

According to another embodiment, the pile foundation-substructure column structures 12 may be bound together by reinforced concrete jacketing for pile foundation-substructure column structures.

FIG. 3 illustrates layouts of steel casing pipes 11. The steel casing pipes 11 are provided to form basic shapes such as a triangle, letters I, L, T or cross shape in top-down view. This is important, because the number of piles/columns is decided by weight and the variable piles/column layouts make it possible to guarantee loading capacity (weight) while providing better/more occupiable space. The combined layouts of pile foundation-substructure column structure in various shapes also allows flexibility and adaptability to different demands of functionalities, architecture of each project. E.g. Providing additional/optimal working space of such areas as basements unattainable using conventional systems.

The individual pile foundation-substructure column structures 12 may be bored, cast-in-situ pile structures, or precast structures such as steel shapes or precast concrete, or pile foundation-substructure column structures including bored, cast-in-situ pile structures and precast structures. For example, in a pile foundation-substructure column system which include three individual pile foundation-substructure column structures, the steel casing pipes are the same but the pile foundation-substructure column structures may be different, e.g. the first pile foundation-substructure column structure is cast-in-situ concrete, the second pile foundation-substructure column structure is precast concrete and the third pile foundation-substructure column structure is constructed by filling a part of the steel casing pipe with concrete, then driving the precast pile into it, thereby constituting an individual structure which includes three material components: steel casing pipe, precast pile and cast-in-situ concrete.

The individual pile foundation-substructure column structures 12 is bound with steel casing pipes 11 by concrete in case the pile foundation-substructure column structure 12 is bored, by welding in case it's a cast-in-situ pile structure and by bolts or adhesives in case the pile foundation-substructure column structure is a precast structure such as steel shape or precast concrete.

One of the advantages of the invention is characterized by connecting pile foundation-substructure column structures 12 into pile foundation-substructure column system working together. For this purpose, the process of concreting for pile foundation-substructure column structure 12 the concrete already adheres to the steel casing pipe 11, therefore, the welding and bolting for steel casing pipes naturally turns them into a homogeneous system. In case greater binding force is required, the concrete beam system (mentioned above) may be used above the heads of the pile foundation-substructure column structures.

As shown in FIG. 4, if the pile foundation-substructure column system forms a closed perimeter, the pile foundation-substructure column system not only bears the load but also plays the role of a retaining wall of the basement thereby maximizing space and increasing cost efficiency.

Furthermore, the present invention provides a method for constructing the aforementioned pile foundation-substructure column system. The fundamental construction process includes:

• • putting steel casing pipes in the stacking sliding system to guarantee uniformity and consistency of the pile foundation-substructure column system. The number of steel casing pipes 11 is also calculated to guarantee the bearing capacity, and the layout design of the steel casing pipes in specific shapes helps achieve requirements of load bearing capacity while providing architectural flexibility;
  • drilling through those casing pipes, to a predefined depth and construct piles by various methods such as cast-in-situ concreting, driving or pressing the precast concrete piles or steel shaped piles, depending on specific conditions and requirements. The steel casing pipes 11, normally corresponding to basement columns, for high-rise buildings, or piers, or bridges, may be fixed, or drawn up for reuse by various methods, wherein piles and columns are bound together by various methods to form a pile foundation-substructure column system with homogeneous operation.

The method to produce the pile foundation-substructure column system includes driving the steel casing pipes 11 in parallel into the ground by such methods as vibrating, pressing or hammering. The steel casing pipes 11 are driven in the stacking sliding guide system, each of which is elevated at a approximate height within the range from the underground surface to the ground level. After that, drill to remove the soil inside the casing pipes 11, with predefined diameter and depth while subsequently constructing the pile foundation-substructure column structure 12 including piles and substructure column constructed inside the steel casing pipes 11, whereby the pile penetrates into the ground with predefined depth and the substructure column extends along the axis of the casing pipe. The steel casing pipes 11 are driven into the ground in the stacking sliding guide system and then bound together to bear the temporary and/or permanent the calculated forces where the piles and substructure column are homogeneously constructed (or monolithic/continuous).

Notwithstanding the abovementioned features, the present invention provides the following advantages:

• • After constructing the pile foundation-substructure column structure, it is possible to construct the superstructure, for example, the body structure of a high-rise building, or the pier, instead of having to wait for various construction processes such as basement excavation, pile cap construction, substructure column construction in the basement;
  • It is possible to use the finished pile foundation-substructure column system to serve other work items such as shoring system or structure for crane installations;
  • The modular piles allow use of one or multiple types of equipment in construction works thereby maximizing cost efficiency for equipment utilization including warranties and maintenance. Meanwhile conventional methods requiring multiple pile diameters reduces cost efficiency due to the need for boring machines of various sizes.

It is easy to test the bearing capacity of the system. There is no need to test large individual piles due to its modular feature.

Although the present invention is described by specific embodiments, it is obvious that various changes and modifications may be made by a person skilled in the art to which the present invention pertains without departing from the true spirit and scope of this disclosure, as defined by the claims.