Patent Application
20150225917
The present invention relates to a structural foundation, and in particular, to a structural foundation having a foundation portion to be fixed to the ground using a spiral pile.
When a post is erected on the ground according to the prior art, a method for fixing the foundation installed in the ground with a pile, erecting a post on the foundation and fixing the post with mortar has been adopted. In particular, the present applicant has put into practice many methods where a spiral pile that is formed by twisting a flat steel plate is adopted as a pile for fixing the foundation.
For example, Patent Document 1 shows a spiral pile that is to be directly driven into the ground in order to provide the foundation for a post. Patent Documents 2 to 4 show a method for creating a hole in a concrete block foundation or a poured concrete foundation installed in the ground, driving a spiral pile into the ground through the hole and fixing the concrete foundation. Such a spiral pile can be easily installed by pouring concrete on site and has the advantage that it is highly resistant to being pulled out due to the fact that the friction with the ground is great.
While the above described spiral pile has a great resistance in response to the force in the direction in which the spiral pile is pulled out, the mechanical strength is weak relative to the stress that is placed on the spiral pile in the horizontal direction or relative to the compressive force in the vertical direction, and therefore the form of the spiral pile changes in the horizontal direction or in the vertical direction, which is a problem because the foundation becomes unstable. In addition, it is troublesome to prepare a concrete foundation where a hole through which a spiral pile can be passed is created. Furthermore, due to its size and weight, transportation and installment of this type of foundation is very costly.
Patent Document 1: Japan Patent No. 4017922
Patent Document 2: Japan Patent No. 3836745
Patent Document 3: Japan Patent No. 4558905
Patent Document 4: Japan Patent No. 4585757
An object of the present invention is to solve the above-described problems and to provide a structural foundation that can support a structure in a stable manner where stress placed on the spiral pile that forms the foundation in the horizontal direction or in the vertical direction can be reduced. Another object is to provide a structural foundation that can be easily installed on site with reduced costs for transportation and installment.
In order to achieve the above-described objects, the invention according to claim 1 provides a structural foundation for supporting a structure or part of a structure, wherein the structural foundation has a foundation portion to be fixed to the ground using a spiral pile, and is characterized in that the foundation portion has a cylindrical steel tube for guiding the spiral pile and a portion for receiving pressure in the horizontal direction, which is placed so as to surround the cylindrical steel tube, and the foundation portion and the spiral pile are provided with a fixing means for connecting the foundation portion and the spiral pile in a state where the spiral pile is inserted into the cylindrical steel tube and the spiral pile is embedded in the ground.
The invention according to claim 2 provides the structural foundation according to claim 1, which is characterized in that the spiral pile has a spiral portion formed by twisting a flat steel plate and a tubular portion for housing and holding one end of the spiral portion, and the tubular portion is placed inside the cylindrical steel tube when the spiral pile and the foundation portion are integrated.
The invention according to claim 3 provides the structural foundation according to claim 2, which is characterized in that the fixing means is formed of a flange provided as a portion of the cylindrical steel tube or as a portion of the portion for receiving pressure in the horizontal direction, and a flange provided as a portion of the tubular portion, and the foundation portion and the spiral pile are connected when the flanges are connected and fixed to each other.
The invention according to claim 4 provides the structural foundation according to any of claims 1 to 3, which is characterized in that the portion for receiving pressure in the horizontal direction is formed of a cylindrical steel tube or formed by joining together sections of a steel H beam, a steel I beam, a steel channel and a steel angle.
The invention according to claim 5 provides the structural foundation according to any of claims 1 to 4, which is characterized in that the foundation portion has a portion for receiving pressure in the vertical direction, and the portion for receiving pressure in the vertical direction is a flat steel plate provided in a space between the cylindrical steel tube and the portion for receiving pressure in the horizontal direction.
The invention according to claim 6 provides the structural foundation according to any of claims 1 to 3, which is characterized in that a part including the cylindrical steel tube and a part including the portion for receiving pressure in the horizontal direction can be separated from each other.
The invention according to claim 7 provides the structural foundation according to claim 6, which is characterized in that the part including the cylindrical steel tube and the part including the portion for receiving pressure in the horizontal direction are linked together, the spiral pile is fixed to either the part including the cylindrical steel tube or the part including the portion for receiving pressure in the horizontal direction, and a space between the cylindrical steel tube and the portion for receiving pressure in the horizontal direction is filled in with concrete that has been poured so as to cover an area where the parts are linked together and an area where the spiral pile is fixed and solidified.
The invention according to claim 8 provides the structural foundation according to any of claims 1 to 7, which is characterized in that at least either one of the spiral pile and the fixing means of the foundation portion is provided with an installation angle adjusting means with which the angle at which the spiral pile is installed and fixed in the ground can be adjusted.
The invention according to claim 9 provides the structural foundation according to any of claims 1 to 8, which is characterized in that at least either one of the spiral pile and the foundation portion is provided with a structure adjusting means with which at least either one of the height or the degree of levelness of the supported structure can be adjusted while the structure is being installed.
The invention according to claim 1 provides a structural foundation for supporting a structure or part of a structure, wherein the structural foundation has a foundation portion to be fixed to the ground using a spiral pile, and is characterized in that the foundation portion has a cylindrical steel tube for guiding the spiral pile and a portion for receiving pressure in the horizontal direction, which is placed so as to surround the cylindrical steel tube, and the foundation portion and the spiral pile are provided with a fixing means for connecting the foundation portion and the spiral pile in a state where the spiral pile is inserted into the cylindrical steel tube and the spiral pile is embedded in the ground, and therefore the integrated spiral pipe and the portion for receiving pressure in the horizontal direction makes it possible for the portion for receiving pressure in the horizontal direction to withstand stress in the horizontal direction and for stress placed on the spiral pile to be reduced. In addition, the cylindrical steel tube holds the spiral pile through the entirety of its length thus preventing the spiral pile from deformation caused by localized stress. Furthermore, this configuration can provide a structural foundation that is resistant to stress in the horizontal direction and can support the structure in a stable manner. Moreover, the spiral pile and the foundation portion can be easily combined at the construction site, and therefore a structural foundation with reduced cost for transportation and installation can be provided.
In the invention according to claim 2, the spiral pile has a spiral portion formed by twisting a flat steel plate and a tubular portion for housing and holding one end of the spiral portion, and the tubular portion is placed inside the cylindrical steel tube when the spiral pile and the foundation portion are integrated, and therefore the tubular portion can be used to guide the spiral pile smoothly into the cylindrical steel tube provided in the foundation portion. In addition, the tubular portion and the cylindrical steel tube work together to increase the strength of contact between the spiral pile and the foundation portion and to increase their integrity as a whole, and therefore a structural foundation that is more resistant to external stress including stress in the horizontal direction can be provided.
In the invention according to claim 3, the fixing means is formed of a flange provided as a portion of the cylindrical steel tube or as a portion of the portion for receiving pressure in the horizontal direction, and a flange provided as a portion of the tubular portion, and the foundation portion and the spiral pile are connected when the flanges are connected and fixed to each other, and therefore the foundation portion and the spiral pile can be connected and integrated without fail.
In the invention according to claim 4, the portion for receiving pressure in the horizontal direction is formed of a cylindrical steel tube or formed by joining together sections of a steel H beam, a steel I beam, a steel channel and a steel angle, and therefore it is possible to form a portion for receiving pressure in the horizontal direction that is more resistant to external stress in the horizontal direction placed on the structural foundation. In the case where a cylindrical steel tube is used, for example, when the steel tube is exposed to pressure, external stress in the horizontal direction placed on the structural foundation can be dispersed throughout the entirety of the steel tube thus preventing deformation caused by stress. In the case where a material having a high level of mechanical strength such as a steel H beam, a steel I beam, a steel channel or a steel angle is used, it is also possible to prevent a localized displacement in the portion for receiving pressure in the horizontal direction.
In the invention according to claim 5, the foundation portion has a portion for receiving pressure in the vertical direction, and the portion for receiving pressure in the vertical direction is a flat steel plate provided in a space between the cylindrical steel tube and the portion for receiving pressure in the horizontal direction, and therefore the flat steel plate receives external pressure in the vertical direction thus preventing deformation of the foundation in the vertical direction and also helping to avoid problems such as the structural foundation subsiding into the ground. In addition, it is possible to use the flat steel plate for linking the cylindrical steel tube to the portion for receiving pressure in the horizontal direction and thus the cylindrical steel tube and the portion for receiving pressure can be more solidly integrated.
In the invention according to claim 6, a part including the cylindrical steel tube and a part including the portion for receiving pressure in the horizontal direction can be separated from each other, and therefore parts that form the structural foundation can be broken down into a greater number of pieces, thus making it possible to further lower the cost for transportation.
The invention according to claim 7 is characterized in that the part including the cylindrical steel tube and the part including the portion for receiving pressure in the horizontal direction are linked together, the spiral pile is fixed to either the part including the cylindrical steel tube or the part including the portion for receiving pressure in the horizontal direction, and a space between the cylindrical steel tube and the portion for receiving pressure in the horizontal direction is filled in with concrete that has been poured so as to cover an area where the parts are linked together and an area where the spiral pile is fixed and solidified, and therefore the foundation can be fixed without fail after the installment of the foundation in the ground.
The invention according to claim 8 is characterized in that at least either one of the spiral pile and the fixing means of the foundation portion is provided with an installation angle adjusting means with which the angle at which the spiral pile is installed and fixed in the ground can be adjusted, and therefore the spiral pile can be installed and fixed in the ground easily while adjusting the angle of the spiral pile.
The invention according to claim 9 is characterized in that at least either one of the spiral pile and the foundation portion is provided with a structure adjusting means with which at least either one of the height or the degree of levelness of the supported structure can be adjusted while the structure is being installed, and therefore the structure can be installed by flexibly adjusting the height and the angle for installment in accordance with the purpose and objectives of the supported structure.
In the following, the structural foundation according to the present invention is described in detail in reference to the preferred embodiments. In the description below, the same symbols are attached to the same members and accordingly the descriptions thereof are not repeated.
The present invention provides a structural foundation for supporting a structure or part of a structure. The structural foundation having a foundation portion to be fixed to the ground using a spiral pile is characterized in that the foundation portion has a cylindrical steel tube for guiding the spiral pile and a portion for receiving pressure in the horizontal direction, which is placed so as to surround the cylindrical steel tube, and the foundation portion and the spiral pile are provided with a fixing means for connecting the foundation portion and the spiral pile in a state where the spiral pile is inserted into the cylindrical steel tube and the spiral pile is embedded in the ground.
As shown in the plan diagram in
Next, the foundation portion according to the first embodiment of the present invention has a structure as in
In the present embodiment, a cylindrical steel tube is used for the portion for receiving pressure in the horizontal direction, and as a result external pressure in the horizontal direction that is received from the ground is dispersed equally throughout the entirety of the portion for receiving pressure in the horizontal direction, and therefore the entirety of the foundation portion 2 can be stabilized.
As shown in
When the foundation portion 2 and the spiral pile 1 are connected the foundation portion 2 is fixed in the ground and then the spiral pile 1 is inserted into the cylindrical steel tube 23 and the fixing means 12 of the spiral pile 1 and the fixing means 22 of the foundation portion 2 are joined to each other. When the fixing means 12 and 22 are joined to each other so that the spiral pile 1 and the foundation portion 2 are connected, the structure in
When a structure or part of a structure is supported using the structural foundation according to the present invention, the structural foundation in
In the embodiment shown in
In the case where the spiral pile 1 of which part of the tubular portion 13 penetrates through the fixing means is used as in
Next, the foundation portion according to the second embodiment of the present invention is described. The structural foundation according to the second embodiment of the present invention shown in
A fixing means 51 provided in the portion 21 for receiving pressure in the horizontal direction in the present embodiment is connected to an upper portion of the portion 21 for receiving pressure in the horizontal direction through a connection member 52, and holes 53 and 54 to be used for fixation to the fixing means of the spiral pile and to a structure or part of a structure are created in the same manner as in the first embodiment. In the lower portion of the part 5 including the portion for receiving pressure in the horizontal direction as shown in
As shown in
In addition, the structural foundation according to the second embodiment of the present invention is formed so that the cylindrical steel tube 55 and the portion 5 for receiving pressure in the horizontal direction can be separated from each other. As shown in
The cylindrical steel tube and the portion for receiving pressure in the horizontal direction can be separated from each other as in the present embodiment so that the structure can be assembled on site and thus a structural foundation can be easily provided with reduced cost for preparation and transportation.
While a steel channel is used for the portion for receiving pressure in the horizontal direction in the present embodiment, a steel H beam, a steel I beam or a steel angle can also be adopted when appropriate. The form of the fixing means and the method for connecting the fixing means are of course not limited to those in the present embodiment.
The construction method for installing the structural foundation according to the present invention in the ground is described below. Initially, a construction method for the structural foundation where a cylindrical steel tube is used as the portion for receiving pressure in the horizontal direction as in
After the foundation portion 2 has been fixed in the ground, the spiral pile 1 is inserted into the cylindrical steel tube 23 and the spiral pile 1 is driven into the ground while being rotated until the fixing means 12 of the spiral pile and the fixing means 22 of the foundation portion 2 make contact with each other. The spiral pile 1 and the foundation portion 2 are linked and fixed to each other by joining the fixing means 12 and the fixing means 22 to each other while adjusting the angle at which the spiral pile 1 is installed using the installation angle means provided in the spiral pile 1 or in the foundation portion 2.
After the spiral pile 1 and the foundation portion 2 have been combined, the structure 4 is placed on the upper portion of the structural foundation 3 and then the structure 4 and the structural foundation 3 are fixed to each other. As for the fixing means at this time, various methods can be adopted as described above, but it is preferable to use double nuts 41 so that the height and the degree of levelness can be adjusted while the structure 4 is being installed.
Finally, the space that has been created between the ground and the structural foundation as well as between the ground and the structure is filled in with a filler 6 such as concrete, mortar or rubble. As a result, the structural foundation installed in the ground can be more firmly fixed to the ground. When this filler covers the portion through which the structure and the structural foundation are linked together, the structure can also be more firmly fixed.
Next, a construction method for the structural foundation where the portion for receiving pressure in the horizontal direction and the cylindrical steel tube can be separated from each other as shown in
In accordance with a method for fixing the part 55 including the cylindrical steel tube in the ground, as shown in
Next, as shown in
Thus, the spiral pile is inserted through the cylindrical steel tube and driven into the ground while being rotated so that the spiral pile 1 and the structural foundation are fixed to each other. The fixing method at this time is the same as that shown in
Thus, the structure or the part of the structure is fixed to the structural foundation. As for the fixing method at this time, various methods can be adopted as described above, and it is preferable to fix the structure or the part of the structure to the structural foundation while adjusting the height and the degree of levelness of the structure using double nuts or the like.
Finally, concrete is poured into the space between the structural foundation and the ground and is left to solidify. As a result, the structural foundation can be fixed to the ground without fail. It is more preferable to pour the concrete so as to cover the points at which the structure or the part of the structure becomes joined to the structural foundation. As a result, the structure or the part of the structure can be fixed more firmly.
While the embodiments of the present invention are described above in reference to the given drawings, of course the design can be modified appropriately and different materials can be selected as long as the gist of the present invention is not deviated from.
The present invention can provide a structural foundation wherein a spiral pile for supporting the foundation can be fixed in such a stable manner as not to displace in the horizontal direction or not to subside in the vertical direction. In addition, the structural foundation can be easily installed on site with reduced costs for transportation and installment.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-221569 | Oct 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/076895 | 10/3/2013 | WO | 00 |
