JPH0328533B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a foundation structure that supports structures such as buildings and civil engineering structures.

[Background technology] In general, foundation structures that support above-ground structures include cloth foundations, independent foundations, direct foundations with underground walls, etc.
There are pile foundations that use piles in combination with these foundations. In these cases, either the bearing capacity of the ground in contact with the bottom of the foundation is expected as the bearing capacity to support the structure, or the friction between the ground around the wall or around the piles is expected as in the case of direct foundations or pile foundations. power and tip support. For this reason, for example, when a large bearing capacity is required on soft ground, it is necessary to use long, large-diameter piles, or to use foundations that require a large amount of expense, such as ground improvement to increase the bearing capacity. This made it unprofitable and did not make full use of the characteristics and strengths of the soil.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to provide a foundation structure that can support a large structure even on soft ground at an extremely low cost. It is in.

[Disclosure of the Invention] The present invention can be applied to a direct foundation such as an independent foundation or a cloth foundation, or a foundation formed of an underground wall, a foundation such as a pile foundation or a foundation beam, and a membrane such as a sheet or net shape. It is characterized in that it consists of a surface member that is laid on the ground surrounded by the foundation and is fixed to the foundation, and it utilizes the soil bearing capacity obtained by the surface member pressing against the ground. This increases the supporting capacity of above-ground structures. Since the surface member here is to constrain the ground surface and integrate the foundation with the ground, it may be any material that has appropriate rigidity or elasticity suitable for the ground in which it is used, such as fibers, synthetic resins, etc. A net-like or net-like membrane made of metal etc. can be used depending on the ground condition, and if a membrane made of fiber is used, woven fabric,
Any form of fabric such as nonwoven fabric, melt fabric, spunbond fabric, felt mat, etc. can be used. However, it is preferable to use a net-like material because it can be expected to have an interlocking effect that restrains soil particles.

The present invention will now be described in detail based on the illustrated embodiments. FIGS. 1 to 3 show an example in which an independent foundation 11 is used as the foundation 1, in which 2 is a surface member and 4 is a It is Kuriishi. A base body 1 passes through a surface member 2 laid on the site ground so as to cover all the site ground, and the surface member 2 is fixed to the outer peripheral surface of the base body 1. In this case, when the load W of the structure 5 is applied to the foundation body 1, the foundation body ₁ supports this load W by the reaction force (supporting force) P1 received from the ground. ₁ is smaller than the load W, the foundation 1 will sink. However, in this case, the basic body 1
Since the surface member 2, which is fixed to the ground and is laid on the ground, restrains and presses the extended ground surface, the surface member 2 obtains a ground reaction force _P2 .
Therefore, the load W of the structure 5 is
P ₁ which is the ground reaction force due to the surface member 2 and
It balances the supporting capacity of +P ₂ .

Figures 4 and 5 show a cloth foundation 12 as the foundation body 1.
6 and 7 show a case where an underground wall 13 is used as the foundation 1. Furthermore, underground wall 1
3 is not limited to one made of reinforced concrete, and may of course be a sheet pile wall or a steel pipe sheet pile wall.

Further, FIGS. 8 to 10 show the case where the base body 1 is composed of independent foundations 11 and foundation beams 14 connecting the independent foundations 11. As is clear from FIG. 10, the surface member 2 is fixed not only to the independent foundation 11 but also to the foundation beam 14. FIG. 11 and FIG. 12 show the case where the pile foundation 15 is used as the foundation body 1. 6 in the figure is a footing.

Now, regarding the fixation of the surface member 2 and the base body 1,
This can be done by making the surface member 2 bind the ground surface and make it behave as one with the foundation 1.As shown in Fig. 13, the surface member 2 should wrap around the bottom of the foundation 1. Alternatively, as shown in FIG. 14, the surface member 2 may be brought into surface contact with the peripheral surface of the foundation 1, and the foundation 1 and the surface member 2 may be fixed by the frictional force between the two due to earth pressure. An adhesive may be applied to the contact surface between the surface member 2 and the base body 1 to bond them together. Furthermore, if the foundation 1 is a pile foundation 15 as shown in FIG. 15, the surface member 2 may be fixed around the foundation 1 by wrapping it with a band 7. In addition, as shown in FIG. 16, a locking tool 7 that projects downward is provided on the base body 1 and the surface member 2 is locked to this locking tool 7, or as shown in FIG. When constructing the foundation 1, the surface member 2 may be embedded and fixed, or as shown in FIG. By inserting the base body 1 into the surface member 2 having an insertion hole 9 having a smaller diameter than the portion 8, or by wrapping or gluing the surface member 2 around the protrusion 8 as shown in FIG. 2 and the base body 1 may be fixed.

The water permeability of the face member 2 may be selected depending on whether or not drainage of the ground is possible, and as shown in FIG. The degree of drainage may be controlled by this control layer 10. In this case, if the surface member 2 has a net shape, the effect of restraining the ground by the surface member 2 will be increased.

Incidentally, in the above-illustrated embodiment, an example was shown in which all the surface members 2 were laid on the ground surface, but they do not necessarily have to be laid on the ground surface, and the surface members 2 may be laid after removing the soil on the ground surface. However, the surface member 2 may be placed underground by backfilling the removed soil. Also, in temporary construction work, etc., the bearing capacity of the ground can be increased by arranging the surface member 2 between the driven sheet piles.

[Effects of the Invention] As described above, in the present invention, the surface member laid on the ground surrounded by the foundation support and fixed to the foundation restrains and presses the ground surface to reduce the ground reaction force, that is, the structure As the bearing capacity increases, so does the bearing capacity of the foundation, so even in soft ground with low bearing capacity, it is possible to improve the foundation without increasing the size of the foundation or using a large number of long pile foundations. It is possible to obtain at least a large support capacity for the structure, and because it makes effective use of the soil bearing capacity of the ground at the site of the structure, it requires a simple structure and is inexpensive and economical. If this is also used in conjunction with improving a portion of the surface layer of the ground, even greater bearing capacity can be expected.

[Brief explanation of drawings]

Fig. 1 is a plan view of one embodiment of the present invention, Fig. 2 is a sectional view of the same as above, Fig. 3 is a sectional view explaining the effect of the above, and Fig. 4 is an example of the case where the base body is a cloth foundation. Plan view, Figure 5 is a broken perspective view of the same as above, Figure 6 is a plan view of an example where the foundation is an underground wall, Figure 7 is a sectional view of the same as above, Figure 8 is an independent foundation where the foundation is an independent foundation. FIG. 9 is a longitudinal cross-sectional view of the same as above, FIG. 10 is a cross-sectional view of the same as above, and FIG. 11 is a plan view of an example in which the foundation body is a pile foundation. , 1st
FIG. 2 is a sectional view of the same as above, FIGS. 13 to 15 are sectional views showing different fixing structures between the surface member and the base body, and FIG. 16 is a perspective view showing another fixing structure between the surface member and the base body. 17 is a sectional view showing another fixing structure for the surface member and the base body, FIG. 18 is a perspective view showing another fixing structure for the surface member and the base body, and FIG.
FIG. 9 is a cross-sectional view showing yet another fixing structure between a surface member and a base body, and FIG. 20 is a cross-sectional view showing another embodiment, in which 1 is a base body, 2 is a face member, and 11 is an independent foundation. , 12 is a cloth foundation, 13 is an underground wall, 14 is a foundation beam, and 15 is a pile foundation.

Claims (1)

[Claims] 1 Direct foundations such as independent foundations and cloth foundations, foundations formed by underground walls, foundations such as pile foundations and foundation beams, and the ground surrounded by the above foundations, which are membranes such as sheet or net shapes. A foundation structure consisting of a surface member that is laid on the ground and fixed to the foundation.