JPH0684626B2 - Light embankment and embankment construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The disclosed technique is to submerge and collapse the embankment before and after constructing a structure such as a passage, a track, a building, and a bank on the embankment on soft ground. Belongs to the technical field of lightweight embankment to prevent.

<Summary of Summary> Therefore, the invention of this application is to support the ground when constructing a structure such as a building, a road, a railroad, a runway, a bridge, a steel tower, a dam body on the ground such as a soft ground. In order to create sufficient embankment on the ground in order to secure sufficient force and ensure the function and space of the structure, a block-shaped piece of which the embankment is lighter than the soil is used as the embankment body in the filling material for the soil, etc. It is an invention relating to a light embankment that is densely laminated on the surface of the embankment and is covered with a cover layer such as soil capable of vegetation, and its construction method. , Cement, void-forming agent, and solid materials such as cement are used to form gravel-shaped pieces with irregular shapes such as volcanic gravel shapes, and irregularity is achieved at a predetermined density in the filler such as soil or cement mortar. The embankment, which is designed to be scattered depending on the condition etc.
And an invention relating to the construction method.

<Prior art> As is well known, in Japan, where the land area is narrow, the coastline is complicated and complicated, and the inland area has many mountains and few plains, and many rivers and lakes are scattered there. Regardless of the soil, there are many soils with a relatively high water content such as soft ground. Therefore, buildings, warehouses, bridges, roads, steel towers, airfields, and even structures such as levee bodies are placed on the ground such as soft ground. There is no choice but to build it, and national land development plans such as land reclamation of coasts and river basins are still being promoted in order to expand the area of the country.

Therefore, it is not preferable to construct the above structure directly on the soft ground having such a high water content in terms of civil engineering, geology, architecture, etc. In structures such as railways, it is necessary to secure a considerable distance, the same level, and an area in an average state. Therefore, for softer soil than before, ground improvement is performed by, for example, the sand drain method. Further, a predetermined embankment is constructed on the upper part of the embankment to construct a predetermined structure on the embankment.

However, since the volume of the conventional embankment is considerable, the load of the embankment itself and the top load of the structure constructed on the embankment cause uneven settlement or lateral swelling. Since there is a possibility that deformation may occur, when embankment is constructed with natural materials of large specific gravity such as soil, rocks and earth and sand, this tendency is particularly large. Was developed, for example, Japanese Patent Laid-Open No. 48
As can be seen in the invention, a technique has been developed in which an artificial embankment body having a specific gravity that is lighter than that of natural soil has been developed, and a characteristic that the embankment body is formed by using a lightweight material such as expanded polystyrene. A technique such as the invention of the Japanese Laid-Open Patent Publication No. 63-32021 has been developed, and further, a plate-like hard foamed plastic as seen in the invention of Japanese Laid-Open Patent Publication No. 62-41822 and the same of Japanese Laid-Open Patent Publication No. 62-197521. The technology related to the embankment body is also being researched and developed.

<Problems to be Solved by the Invention> However, in such a technique, the artificial embankment body is made lighter than natural soil, and there is an advantage that uneven settlement of the ground such as soft ground is prevented as much as possible. ,
In Japan, which is one of the most prominent earthquake nations, lateral vibrations caused by earthquakes are applied to the embankment, or when the embankment is slipped when a sloshing load of river, lake, seawater is applied to the embankment. There is a drawback that this cannot be prevented from the point that the main body of the embankment is not structurally integrated, and in the case where the main body of the embankment is a chemical product etc., there is a possibility that the fire resistance against the occurrence of a fire in the surroundings is poor, and However, when there is a large amount of precipitation or high temperature solar radiation, the embankment itself is metamorphosed, and when there is a large amount of precipitation, the infiltration water causes the substrate of the embankment body to elute and penetrate into the groundwater, which may cause pollution problems. Yes,
In addition, there was a problem that it was difficult to control the uplift due to buoyancy due to the large amount of precipitation and the rise in the groundwater level.

To deal with this, for example, as seen in the invention of Japanese Patent Laid-Open No. 63-47434, a bag made of a predetermined synthetic resin is filled with an artificial lightweight material such as Styrofoam or vermiculite to be hermetically sealed and laminated to form a dense packing. In this state, the main body of the embankment is formed, or as shown in the invention of JP-A-64-17902, an ultra-lightweight hollow type synthetic resin box is fitted with the uneven portions on the outer surface thereof to each other. There is also a technology of embankment main body structure of mechanical connection mode that piles up to a predetermined size, but these are produced in advance at the factory and carried into the construction site, and further, at the construction site, alignment and bonding lamination as designed are done. It has to be carried out, has a disadvantage that the work is extremely troublesome and the cost is extremely high, and it is integrated as a whole embankment in the horizontal direction, that is, not only in the horizontal direction, but also in the vertical, horizontal, and diagonal directions. Charge to prevent operation There was to have not been insufficiency on the effective.

Therefore, for example, as in the inventions of JP-A-1-125401 and JP-A-1-142117, there is a technique of covering, adding, or integrating a reinforcing net to a lightweight block to increase the strength. However, complicated work was required for the construction, and for that reason, there was a mass point that construction accuracy in all areas could not be improved as designed.

Therefore, in order to mold the embankment body into a block shape, an extremely delicate mold etc. is required. Moreover, since it is a diversion of the intended application of the original block, it is costly. There was a disadvantage that they did not fit.

There is also a technique in which the joints of the lightweight concrete block and the polystyrene foam are displaced from each other and laminated so as to improve the safety of the embankment as in the invention disclosed in JP-A-2-128017. There is a demerit that it is technically impossible to carry out on-site construction because it is extremely complicated to manage and improve the accuracy.

There is also a technology that connects the lightweight blocks mechanically in the horizontal direction as seen in Japanese Utility Model Laid-Open No. Sho 63-185837, but it is sufficient for operation in vertical and diagonal directions due to earthquakes and groundwater buoyancy. I didn't like to deal with.

Further, these embankment structures have a so-called top-heavy structure, and there is a problem that slip is likely to occur when a lateral load is applied due to an earthquake.

Further, when a load is applied, the aggregate and the cement paste are separated and separated, and as a result, there is a negative point such as cracking.

When a so-called lightweight material is used, the structure becomes a top-heavy structure as described above, and a technique for coping with skidding has not been sufficiently developed.

<Object of Invention> An object of the invention of this application is to solve the problems of the embankment when constructing various structures such as buildings and roads on the ground such as soft ground through the embankment based on the above-mentioned prior art. The construction work can be done smoothly and at low cost.
After the construction, the embankment can maintain its initial functions sufficiently against earthquakes, fires, water damage, etc. as designed, and the upper structure can also fully perform those functions in the construction industry. The purpose of the present invention is to provide an excellent lightweight embankment and an embankment construction method that benefit the field of civil engineering applications.

<Means and Actions for Solving the Problems> In order to solve the above problems, the structure of the invention of the present application, which is based on the above-mentioned claims and has the purpose of solving the above-mentioned problems, has an embankment on the ground such as soft ground. When constructing the embankment prior to constructing the specified structure, cement, water, a void-forming agent material such as fine foam is mixed and agitated as required, and waste material such as coal ash of a thermal power plant is also used. Is sprayed into cold water and solidified to form gravel-shaped gravel-shaped solid pieces such as volcanic gravel, small pieces, etc., and these pieces are used as the embankment body in the soil or in a scattered state with filler such as soil and cement mortar. Mix the pieces into a meshed state in which the opposite ridges are in the posture corresponding to the pitted recesses, carry them to the construction site with a dump truck, etc., and shape them into the prescribed embankment body with a backhoe etc. Molded and, if necessary, surrounded by a cover material such as geotextile on the surface of the embankment body to increase filling strength and overall rigidity,
Adjacent pieces are firmly interlocked with each other through the filling material so that the entire embankment is firmly integrated and the entire surface is covered with the embankment body for vegetation work etc. A predetermined structure is constructed on the upper surface, and since the embankment main body that occupies most of the vegetation is lighter than the soil, the load of the embankment itself, further, Uneven sinking does not occur due to the top load of the upper structure, etc., and because of the integrated structure by mutual meshing of solid pieces, horizontal vibration such as earthquakes and buoyancy due to groundwater can cause vertical, horizontal, and diagonal behavior. It is suppressed, the above-mentioned initial formation state is maintained, fire resistance and integrity are obtained by the soil etc. of the cover layer, the elution of the solid piece substrate due to precipitation is avoided, and the function of the embankment is maintained as originally designed Technology In which it took measures.

<Example> Next, an example of the invention of this application will be described with reference to the drawings.

Reference numeral 1 is a lightweight embankment that forms the center of one aspect of the invention of this application, and is applied to the soft ground 2 when constructing structures such as buildings and roads on the soft ground 2 as in the conventional mode. The embankment body 3 is directly formed, and the inner embankment body 3 and the coating layer 4 on the surface thereof, and depending on the design, an appropriate holding material 5 such as a geotextile is interposed therebetween.

The embankment body 3 is, as shown in FIG. 3, artificially preliminarily formed in large quantities in a factory with a mold or the like in a gravel-shaped solid piece 7,7 ... As shown in FIG. 2, each piece 7 is made up of a filling material 7 and the like inserted therein, so that at the time of construction, the pointed portion and the pitted recess face each other so that a relatively meshing posture can be taken. For example, water and a foaming agent such as fine foam or monocrete are stirred, mixed, and dispersed by an appropriate high-speed rotary foaming device, and this is kneaded with water and cement in advance. In addition to the cement paste, the mixture is mixed and stirred, and the foamed paste is used as a raw material and poured into an appropriate mold to form, but such a technique can be sufficiently realized at the technical level at the time of the invention of this application. And, for example, coastal wave-dissipating blocks Possible of not due to elaborate molding used for other purposes molding, rather, microscopic resolution is one or a molded article is not limited.

In this case, as a design example, it has been experimentally obtained as data that the cement water ratio should be 52.3% and the foaming agent should be 0.5% of the cement.

As an equivalent of such an aerated paste, there is ALC of an aerated concrete product by autoclave curing, etc., as described later.

In this case, the pieces 7 are not all the same in size and shape, and the shape and the size are irregular random shapes in which the ridges and the pits can face each other and mesh with each other. It is desirable that the shape is

Since the piece 7 is a bubble-forming material,
It is significantly lighter than ordinary natural soil, and as long as it is lightweight, it may be a waste material such as a crushed material such as coal ash from a thermal power plant.

When the pieces 7, 7 ... Obtained in this way are mixed with the filling material 8 such as the local natural soil by an appropriate mixer or the like, as shown in FIG. As described above, since the pointed portion and the pitted concave portion are opposed to each other and mesh with each other from the naturally dispersed state, an irregular and possibly uniform mechanically dense posture can be obtained. Are spatially arranged.

In this case, there is no particular problem with the size of the solid pieces 7, 7 ...

In this way, the embankment body 3 is prepared as a material and, as shown in FIG. 4, is loaded into a predetermined area of the soft ground 2 on site by a dump truck 9 or the like, and further, as shown in FIG. The backhoe 10 is used to form and build the excitement body 3 ″ as designed.

In this case, depending on the design, as described above, the pressing material 5 such as geotextile is covered on the surface of the embankment main body 3 to strengthen the embankment main body 3 ″, strengthen the rigidity, and strengthen the paving strength. On the surface of the swelling body 3 ″, a local natural soil is laid as a coating layer 4 with a predetermined thickness such as a thickness of 2 m (the thickness may be the same as in the conventional mode) to form the embankment 1.

In this case, it is within the design range to appropriately apply a rolling force by a stamper or the like in each process.

And, as the material of the piece 7, foamed mortar, foamed paste, ALC, mortar using various lightweight aggregates, EPS such as Styrofoam, urethane foam, polyurethane, various lightweight materials such as vermiculite are used.
Examples of the filler include fluidized soil as disclosed in JP-A-1-264944, mud, an appropriate solidifying material, water mixed and stirred to form a milk, or ,
It is also possible to use a soil and a solidifying material (in such a case, a design mode in which water is not mixed is possible), and silt or sandy soil can be used.

When the pieces are embedded in the filling material as described above, the pieces are light in weight by filling with the solidifying material to be solidified, but the pieces are prevented from receiving buoyancy due to groundwater or the like.

Next, the experimental mode according to the predetermined design is as follows.

Piece unit volume mass: 1000 kg / m ^3, unit volume mass fluidizing treated soil filler: 1300 kg / m ^3, milk: 2300 kg / m ^3, silt: 180
0kg / m ³ , sandy soil: 1900kg / m ³ , coating layer (unit volume mass of thickness 2m: 2000kg / m ³ ) The weight reduction rate for each void filling material is shown in the following table based on the above data. Is.

The embodiment of the invention of this application is not limited to the above-mentioned embodiments, and for example, when each piece is used as the material of the embankment body, vibration is appropriately applied in the mixing process with the filler. It is possible to employ various modes such as the pointed portion and the pitted concave portion facing each other so as to be in a more densely meshing posture so that a filler is not interposed therebetween.

Further, in terms of design change, solid pieces of the same shape size may be used, or pieces of various sizes may be used.

In this case, by sequentially applying vibration to the piece group or the mixed group of the piece and the filler, the adjacent pieces are surely engaged with each other by the projections and the pitted depressions. Posture, make sure that the embankment body is in a dense state, and even if a lateral load such as an earthquake or upward buoyancy due to water content, or a diagonal load due to these comprehensive loads is applied, the whole body is integrated. The rigidized state is maintained so that slippage, collapse, and cracks do not occur.

Due to the scattered and filling postures of the pieces in the filling material in such a state in which they interlock with each other, the embankment via rolling compaction etc. maintains sufficient strength as a structure and compaction state, and unexpected loads and construction Behavior and transformation due to heat such as fire afterwards can be avoided, the elution of the substrate of the piece due to precipitation infiltration, etc. can be reliably suppressed, and the function as embankment will change sequentially as designed. No, it can be maintained for a sufficient service life.

In addition, even if the seismic load or the equivalent load is applied in excess of the design, which is unexpected, the meshing state between the pointed part and the recessed part of the solid piece is further promoted, and the compaction posture is improved. Rather, it will be enhanced, and the function will be enhanced.

Of course, the above-mentioned function is further strengthened by performing improvement work on the soft ground of the foundation in advance by using a conventional technique such as sand drain.

<Effects of the Invention> As described above, according to the invention of the present application, basically when the embankment on which the structure of the building and the road is to be constructed is formed on the ground such as the soft ground, the embankment body is made lightweight. The effect of being able to sufficiently support the upper structure without causing uneven settlement or collapse due to the large weight of the embankment or the applied load and skidding due to top heavy or the like.

Thus, the embankment body is made up of small gravel-shaped pieces of random size that are directly adjacent to each other in a random shape, or scattered in the filling material such as local soil. The pointed protrusion and the pitted recess face each other so as to engage with each other to form a posture arrangement, and a solid integrated compact state appears as a whole. Even if it appears, there is a top load, there is a lateral load such as an earthquake, and even if buoyancy occurs due to groundwater, etc., an integrated compaction state is firmly formed, and its behavior Since it promotes and strengthens the packed state, uneven settlement does not occur, skidding and rising do not occur, and as a result, cracks do not occur and the embankment is fully constructed as it was in the initial design state. The excellent effect of being able to exert the function of It is.

Then, when forming the embankment body of the solid pieces or when they are scattered in the filler, by designing a process such as continuing appropriate vibration for a predetermined time, a sufficiently dense state is obtained and integrated compaction is performed. The posture is formed, and this does not cause behavior due to unexpected load, thermal behavior or transformation due to severe heat or fire in the vicinity, and it is excellent in that it can maintain the original design shape of the embankment and exert its function. The effect is played.

Further, since the embankment body is formed as a gravel-shaped solid piece dense arrangement interposing structure, when constructing a structure on the upper part of the embankment, it is also possible to engage the foundation of the structure with the piece. Therefore, it is possible to stabilize those foundations, and as a result, it is possible to sufficiently exert the durability and function of the upper structure.

[Brief description of drawings]

The drawings are schematic views of an embodiment of the invention of this application, FIG. 1 is a schematic cross-sectional view of the embankment, FIG. 2 is a schematic view of an intermediate arrangement of solid pieces, and FIG. 3 is a partially enlarged schematic perspective view of the embankment body. ,the 4th,
FIG. 5 is a schematic cross-sectional view of construction of the embankment body, and FIG. 6 is a cross-sectional view of one embodiment of the embankment after completion. 1 ... Embankment, 2 ... Soft ground, 3 ... Embankment body, 4 ... Covering layer, 5 ... Pressing material, 6 ... Piece, 7 ... Piece body, 8 ... Filling material

Claims (5)

[Claims] 1. A lightweight embankment in which a solid piece, which is lighter than soil, is laminated as a embankment body on a foundation ground, and a covering layer is covered on the surface of the solid body, wherein the embankment body is formed into a gravel-shaped piece and mutually. Lightweight embankment characterized by being scattered in the filling material in a posture corresponding to meshing. 2. The lightweight embankment according to claim 1, wherein fine bubbles are formed in the piece. 3. The lightweight embankment according to claim 1, wherein the piece is formed of a waste material. 4. A lightweight embankment in which a solid piece, which is lighter than soil, is layered as a embankment body on a foundation ground, and a coating layer is covered on the surface of the solid body, wherein the embankment body is formed into a gravel-shaped piece and is mutually attached. Lightweight embankment characterized by being scattered in the filling material and being pressed by the pressing material in a posture that allows for meshing. 5. A lightweight embankment construction method in which a large number of solid pieces, which are lighter than the soil, are densely provided as a main body of embankment on a foundation ground in a filler, and the surface thereof is covered with a coating layer. A lightweight embankment construction method, characterized in that a main body is formed into gravel pieces using a void-forming agent and a solid material, and a large number of the pieces are scattered irregularly between the fillers.