JP2807833B2 - Method for correcting uneven settlement of structures - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for correcting uneven settlement in a structure, in which a load from a superstructure is transmitted directly to the ground from a solid foundation or an independent foundation.

(Prior Art) Usually, when there is a viscous soil layer that causes consolidation settlement in the ground supporting a structure, a pile foundation that penetrates the pile to a solid support layer is adopted. For example, on the ground in a landfill area such as a sea marsh, a thick pile of soft layers is required, so even a low-rise structure of three stories or less needs long piles. As a result, the ratio of the pile foundation construction cost to the construction cost increases.

 An alternative method that does not use piles is shown below.

<B> A floating method that reduces the weight and prevents settlement by excavating and eliminating the amount of soil equivalent to the weight of the structure.

<B> Ground improvement method to improve the soft layer that is likely to sink.

<C> A method in which a jack is set between the foundation and the upper structure in advance, and when uneven settlement occurs, the jack is adjusted to correct the uneven settlement of the structure.

<D> By laying water supply / drainage pipes in advance on a foundation with a pressure-resistant version, when uneven settlement occurs, water is supplied to an area with little settlement to promote settlement in the area and correct uneven settlement of structures. Construction method.

(Problems to be Solved by the Invention) The above-mentioned conventional methods for preventing or correcting settlement have the following problems, respectively.

(1) In the method <a>, a method for accurately predicting the settlement amount has not been established, and when the soft layer is not uniform,
It is over-designed and uneconomical. Also, as a result of adoption,
There is no certainty in subsidence correction, as it can result in larger subsidence than expected.

(2) The construction method <B> is the same as the above <A>.

(3) In the construction method of <c>, since the foundation and the upper structure are not structurally integrated, the construction of the structure is complicated and the cost increases. Also, the settlement of the foundation itself cannot be corrected. Furthermore, it is unstable against earthquakes.

(4) In the method <d>, since a large amount of water is used, it takes a long time to correct the settlement. The softening of the ground may be accelerated, and the settlement may be increased. There is a danger that settlement will affect nearby buildings. Water supply management for settlement correction is difficult. Therefore, the settlement correction is not certain.

(Object of the Invention) It is an object of the present invention to provide a method for correcting uneven settlement in a structure, which has been made to solve the above-mentioned conventional problems.
The purpose is to construct a structure on the ground under the condition that the relatively soft soil layer where the structure is located is thickly deposited. If unequal settlement is expected,
There is a way to correct the differential settlement of the structure.

(Means for Solving the Problems) The invention according to claim 1, wherein the ground is excavated to a level of a predetermined depth from the lower surface of the foundation of the structure to be constructed, and the excavated ground surface below the foundation where the underground beams are orthogonal to each other. On the top, an injection bag for enclosing the injection material is installed horizontally, one end of an injection pipe is connected to the injection bag, and from the upper part of the excavated ground surface to the lower part of the foundation to be built, the earth and sand are spread and leveled. And the upper structure is constructed, and at the initial stage of the construction of the structure, a level is measured at an arbitrary point of the structure and a reference value is recorded, and after the completion of the structure, the arbitrary point of the structure is Level measurement, as a result, if harmful uneven settlement of the structure is expected, in the injection bag installed below the foundation caused by the uneven settlement, from the other end of the injection pipe connected to the same bag A structure that injects a grout and modifies the foundation and structure levels It is in the method of correcting uneven settlement of objects.

According to a second aspect of the present invention, in the method for correcting uneven settlement of a structure according to the first aspect, the injection material has a property of solidifying at room temperature and liquefying at a high temperature, and injects the injection material liquefied by heating into a bag. The method of correcting uneven settlement of a structure.

According to a third aspect of the present invention, there is provided a method for correcting settlement of a structure according to the first aspect, wherein a heating wire is incorporated in an injection pipe and an injection bag.

According to a fourth aspect of the present invention, there is provided a method for correcting the differential settlement of a structure according to the first aspect of the present invention, wherein the injection bag has an inner wall material made of a material having releasability.

(Operation) Since the invention of claim 1 of the present invention is configured as described above, if there is a possibility that harmful uneven settlement may occur in the structure as a result of the level measurement of the structure, the foundation caused by the settlement may be generated. The injection material is sealed by the injection pipe into the injection bag installed below the injection bag. The filling material inflates the filling bag, thereby modifying the foundation and the structure to a regular level.

Since the sand is filled between the injection bag and the excavated ground with the correction of the differential settlement, no void is formed around the injection bag.

According to the second aspect of the present invention, since the injection material is a material which solidifies at room temperature and liquefies at a high temperature, and the liquid injection material is injected into the injection bag, the operation can be performed easily and in a short time.

According to the third aspect of the present invention, since the heating wire is built in the injection pipe and the injection bag, the first time the injection material is solidified in the injection bag and the injection pipe when the injection material is injected after the second settlement. By liquefying the injection material, re-injection becomes easy.

In the invention of claim 3, the inner wall material of the injection bag is made of a material having good releasability. It becomes easy to inject the injection material after the first time.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

<A> Structure and its foundation This will be described with reference to FIGS. 3 and 4, FIG. 13 and FIG.

The structures A and A 'are composed of foundations a and a' and an upper structure b having a first basement floor and a two-story building standing on the foundations a and a '.

The foundation is a solid foundation a or an independent foundation a '.

The solid foundation a comprises an underground beam 1 and a bottom plate (pressure-resistant version), and the bottom plate is installed at the lower end of the underground beam 1 (FIGS. 3 and 4).

The independent foundation a 'is a footing foundation. Independent foundation a '
The underground beam 1 crosses the foundation a 'and is connected to each adjacent foundation a' (FIGS. 13 and 14).

Since the foundation is configured as described above, the solid foundation a having the underground beam 1 and the independent foundation a 'support the load from the upper structure b and directly apply the load to the ground without using a pile or the like. It has a structure to tell.

<B> Ground excavation Excavation ground B of the structure to be constructed is converted into the foundations a and a 'of the structure.
Excavation is performed to a predetermined depth, for example, about 1 m below the lower surface of the ground.

The excavation ground B is a space for disposing an injection bag 3 described later and further laying sand 5 thereon.

<C> Infusion bag (Fig. 12) The infusion bag 3 is horizontally installed on the surface of the excavated ground B below the foundations a and a 'where the underground beams are orthogonal.

As shown in FIG. 1, the infusion bag 3 has an inner central bag 3A, an outer bag 3B, and a corner bag 3C below each intersection of the underground beam 1.

The injection bag 3 is a bag for enclosing an injection material, and is connected to the injection pipe 2.

The injection bag 3 is made of a flexible and durable material.

The injection bag 3 is made of a material having releasability for the inner wall material of the bag. Thereby, when performing the injection repeatedly,
The solidified injection material is easily peeled from the bag 3.

The injection bag has a built-in heating wire 7 and is arranged in a meandering manner. One end of a heating wire 7 ′ built in the injection pipe 2 is connected to the wire 7. And
By energizing the heating wire 7 ', the bag 3 is heated and sealed, and the solidified injection material is liquefied, and the injection material is easily peeled off from the bag 3.

<D> Injection pipe (FIGS. 11 and 12) The infusion pipe 2 has a built-in spiral heating wire 7 ′, and one end thereof is connected to the heating wire 7 incorporated in the infusion bag 3. It is.

The injection pipe 2 is made of a material having pressure resistance, flexibility, and elasticity.

The injection pipe 2 has one end connected to the injection bag 3 (FIG. 12). The injection pipe 2 may be connected to the injection bag 3 in advance, or may be connected when the same bag 3 is installed.

The injection pipe 2 has branch pipes 2A, 2B, and 2C connected to each of the injection bags 3A, 3B, and 3C, respectively, and the branch pipes 2A, 2B, and 2C.
Is connected to the injection material supply pipe 2D.
2D is connected to an inlet 6 provided on the ground (FIG. 2).

FIG. 2 is a system diagram of the injection pipe. The outline is shown below.

Inner-center intersection bag 3A, outer intersection bag 3B, corner intersection bag
One end of each branch pipe 2A, 2B, 2C for injection is connected to each bag of 3C. The other end of each branch pipe 2A, 2B, 2C is connected to one end of the injection material supply pipe 2D. The other end of the injection material supply pipe 2D is connected to an injection material storage tank (not shown), and the storage tank is provided with an injection pump P. The injection material storage tank is provided with a discharge port for discharging the injection material from the storage tank to the injection pipe 2D (not shown).

Each of the branch pipes 2A, 2B, and 2C includes a cock 4A, 4B, and 4C, respectively, and the injection material supply pipe 2D also includes a cock 4D.

For example, the injection into the injection bag 3A is performed by opening the cock 4D of the injection material supply pipe 2D and the cock 4A of the branch pipe 2A, closing the cocks 4B and 4C of the other branch pipes 2B and 2C, and operating the pump P. This allows the injection material to be injected into the central intersection bag 3A (FIG. 1).

With the above piping system, the injection material can be supplied to the injection bag 3A for correcting uneven settlement.

<E> Injecting material The injecting material used is a material that solidifies at room temperature and becomes fluid when heated.

In the case of the first non-uniform settlement correction, a solidified material such as a cement slurry or mortar is used at room temperature.

In the case of the second and subsequent uneven settlement correction, a material having a thermoreversible property such as paraffin or a synthetic resin is used as the injection material.

That is, at the time of the first uneven settlement correction, the injected material in the bag 3 is solidified. Therefore, at the second and subsequent uneven settlement corrections, the solidified injection material is heated and liquefied, and the second and subsequent times are fixed. An injection material for correcting uneven settlement is additionally injected into the injection bag 3.

<F> Heating wire Heating wire The injection bag 3 has a meandering built-in heating wire 7 for liquefying the solidified injection material (FIG. 12).

A heating wire 7 ′ for injecting the injection material in a liquefied state is helically incorporated in the injection pipe 2 (the eleventh heating wire).
Figure).

In other words, the injection material in the bag 3 is solidified at the time of the first uneven settlement, and therefore, at the second and subsequent uneven settlement, the solidified injection material is heated by the heating wires 7, 7 '. This makes it easy to additionally inject the injection material for the second and subsequent non-uniform settlement into the injection bag 3.

<G> Method of correcting uneven settlement of a structure A method of correcting uneven settlement of a structure A having a solid foundation a shown in FIGS. 3 and 4 will be described with reference to FIGS. 5 to 10. FIG.

A predetermined depth from the lower surface of the solid foundation a of the structure A to be constructed;
For example, excavate the ground to a depth of about 1 m (Fig. 5).

On the surface of the excavated ground B below the foundation a where the underground beams 1 of the solid foundation a are orthogonal to each other, an injection bag 3 for enclosing the injection material is horizontally installed, and an injection pipe 2 is provided. One end of the injection pipe 2 is connected to the injection bag 3 (the 12th
FIG. 6), the other end of the pipe 2 is connected to an injection material inlet 6 (FIG. 6).

The arrangement of the injection bag 3 and the injection pipe 2 is shown in FIGS.
As shown in the figure, a branch pipe 2 is provided for each of the injection bags 3A, 3B, 3C.
A, 2B and 2C are connected.

At this time, one end of a pipe for filling the sand 5 is installed on the lower surface of each of the injection bags 3A, 3B, 3C, and the other end is left on the ground (not shown).

After the soil 5 is spread on the surface of the excavated ground B to the lower part of the solid foundation a to be constructed and the injection bag 3 and the injection pipe 2 are buried (FIG. 7), the solid foundation a and the upper structure b are removed. Build (Fig. 8). The earth and sand 5 is preferably solid sand.

An initial stage of the process of constructing the structure b, for example, a level measurement around each pillar on the first floor above the ground is performed, and an initial value (reference value) is recorded.

After the completion of the structure A, the level measurement around each pillar on the first floor above the ground is performed again, and the measured value is recorded and compared with the reference value.

In general, when the excavated ground B that supports the structure A is a clayey soil layer, dense settlement continues for a long period of time, but the amount of settlement is large in a relatively early stage. Therefore, from the initial stage immediately after completion,
The level measurements of the columns are taken periodically and recorded and compared with the reference values each time.

As a result of the level measurement, as shown in FIG. 9, when harmful uneven settlement is expected for the structure A, the injection bag 3 (the bag shown in FIG. 1) installed below the solid foundation a where the settlement is large.
3A), an injection material, for example, mortar, is injected from the injection port 6 of the injection pipe 2 connected to the bag 3.

Since the injection bag 3 is inflated by the mortar being enclosed, the solid foundation a and the structure b at the site of large sinking
Is gradually corrected to the normal horizontal level by the inflation pressure. Since the mortar is solidified at room temperature, the structure A can be stably kept horizontal (FIG. 10).

When the structure A is corrected for uneven settlement horizontally, the solid foundation a
A gap is formed between the pressure plate and the excavation ground B, and sand is pressure-fed and filled into the gap by a pipe previously guided to the surface from the excavation ground B (not shown).

After a certain period of time, for example, two to three years, after the above-mentioned differential settlement correction, the level measurement is performed again as described above, and the measured value is compared with the reference value.

As a result of the level measurement, if harmful non-uniform settlement of the structure A is expected, injection is performed in the same manner as described above.

The mortar that has been injected and solidified during the first uneven settlement correction is melted. That is, the mortar is liquefied from the surface of the injection bag 3 by energizing the heating wire 7 provided inside the injection bag 3.

In the liquefied state, the injection material to be injected into the second non-uniform settlement is, for example, paraffin, and the injection below the solid foundation a with large settlement is performed by the injection pipe 2 similarly to the injection at the time of the first correction. Inject into bag 3. Paraffin is mainly encapsulated in the liquefied mortar part. As a result, the filling bag 3 is inflated, so that the solid foundation a and the structure b are gradually corrected to a regular horizontal level by the inflation pressure. The paraffin solidifies gradually and the structure A
Will maintain a stable level.

After the correction of the structure, the gap between the pressure plate of the solid foundation a and the excavation ground B is filled with sand under pressure.

After the above-mentioned uneven settlement correction, after a certain period of time, perform a level measurement in the same manner as described above, compare the measured value with the reference value, and if harmful uneven settlement of the structure A is expected,
The third correction is performed in the same manner as the second correction.

FIGS. 13 and 14 show the independent foundation a 'applied to the present invention.
And a structure A 'composed of the upper structure b.

In this case, the injection bag 3 may be installed on the excavated ground B and directly below the independent foundation a '. Thereby, the excavated ground B can be made shallow.

Although the settlement measurement of the structure A is performed by measuring the level around each pillar at an arbitrary floor, the floor level measurement is performed by a floor tilting device at an arbitrary floor, and the uneven settlement amount is managed instead. You can also.

In addition, an inclinometer can be installed on the underground beam 1 to measure the level of the underground beam 1 and manage the amount of uneven settlement.

(Effects of the Invention) Since the present invention has been described above, the following effects can be obtained.

<A> With the conventional method, a structure to be constructed on soft ground, for which a foundation could not be directly adopted, can be constructed and is extremely economical.

<B> By correcting and controlling the differential settlement of the structure, it is possible to correct the differential settlement even if there is a variation in the thickness of the soft ground due to the differential settlement.

<C> By correcting and controlling the differential settlement of the structure, it is possible to correct the differential settlement even when there is a variation in the load of the upper structure in the structure caused by the differential settlement.

<D> Unlike conventional water injection methods, not only differential settlement,
Even when the subsidence (natural subsidence) continues, it is possible to correct the subsidence.

<E> Unlike the conventional settlement correction by jack-up, the foundation is not damaged.

<F> Even if the structure is tilted in the event of an earthquake, it is possible and easy to correct uneven settlement.

<G> In the case of a structure having a basement, settlement correction is much more rational and less costly than the conventional method.

<H> Since the earth and sand can be spread and leveled between the excavated ground and the foundation and the sand can be filled even after the uneven settlement of the structure is corrected, no void is generated between the excavated ground and the foundation. Since the injection material sealed in the injection bag is liquefied and injected by heating,
The work can be performed easily and in a short time.

<I> Since the heating wire is incorporated in the injection bag and the injection pipe, the solidified material of the previous injection is liquefied by heating, and can be easily additionally injected.

<N> Since the inner wall material of the injection bag is made of a material having a peeling performance, the separation of the solidified material of the preceding injection into the injection bag, together with the liquefaction by heating, allows the additional injection to be performed very easily.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a layout view of an injection bag applied to a method for correcting uneven settlement of a structure according to the present invention. FIG. 2 is a functional system diagram of an injection bag and an injection pipe. FIG. 4 is a longitudinal sectional view of a solid foundation of a structure applied to the present invention. FIG. 5 to FIG. 10 are diagrams showing steps of a method for correcting uneven settlement of a structure of the present invention. Fig. 11 is a perspective view of an injection pipe. Fig. 12 is a perspective view of an injection bag. Fig. 13 is a plan view of an independent foundation of a structure applied to the present invention. Fig. 14 is the same structure. Longitudinal cross-section of the independent foundation (signs) A, A '... structure, B ... excavated ground, P ... pump, H
... power supply a ... solid foundation, a '... independent foundation, b ... structure, 1
… Underground beam 2… Injection pipe, 2A, 2B, 2C …… Injection pipe (branch pipe) 2D …… Injection pipe (supply pipe) 3A, 3B, 3C …… Injection bag, 4A, 4B, 4C, 4D …… cock 5 …… sand, 7,7 ′ …… heating wire

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Fushiro Tanizawa 1-25-1, Nishishinjuku, Shinjuku-ku, Tokyo Inside Taisei Corporation (72) Inventor Masajuge Muramatsu 1-25, Nishishinjuku, Shinjuku-ku, Tokyo No. 1 Taisei Corporation (56) References JP-A-1-312123 (JP, A) JP-B-54-19083 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB Name) E02D 35/00 E02D 27/34 E02D 27/38

Claims (4)

(57) [Claims] 1. An excavation ground for excavating a ground to a predetermined depth from a lower surface of a foundation of a structure to be constructed, and an injection bag for enclosing an injectable material is provided on the excavated ground surface below the foundation to which an underground beam is orthogonal. Install horizontally, connect one end of the injection pipe to this injection bag, spread the earth and sand from the upper part of the excavated ground surface to the lower part of the foundation to be built, build the foundation and the upper structure, At the initial stage of construction of a structure, measure the level at an arbitrary point on the structure and record the reference value.After completing the structure, measure the level at an arbitrary point on the structure. When harmful uneven settlement is expected, the injection material is injected from the other end of the injection pipe connected to the bag into the injection bag installed below the foundation caused by the uneven settlement, and the foundation and structure Repair of structures, characterized by level correction Right way. 2. The method for correcting uneven settlement of a structure according to claim 1, wherein the injection material has a property of solidifying at room temperature and liquefying at high temperature, and injects the injection material liquefied by heating into a bag. A method for correcting uneven settlement of a structure. 3. The method of claim 1, wherein a heating wire is incorporated in the injection pipe and the injection bag. 4. The method of claim 1, wherein the infusion bag is made of a material having a releasable inner wall material. .