JP6991182B2 - Retaining wall construction method - Google Patents

Description

The present invention relates to a retaining wall construction method used for constructing a retaining wall for retaining earth on a mountain surface, a road side surface, a constructed land side surface, or the like.

Conventionally, as a retaining wall for retaining soil, as shown in FIGS. 10A to 10D, ready-mixed concrete was cast on the ground 2 at the retaining wall construction site, and the whole was composed of a concrete body 12. A plurality of on-site retaining walls 1A and concrete molded products 13 (hereinafter referred to as concrete blocks) having a hollow inside as shown in FIGS. 11A to 11 are assembled vertically and horizontally, and the concrete thereof is assembled. Various forms such as a block stacking retaining wall 1B formed by filling an internal vacant space of the block 13 with a filler 14 (soil, crushed stone, ready-mixed concrete, etc.) are used.

In the on-site retaining wall 1A shown in FIGS. 10A to 10D, the one in (A) is a trapezoidal gravity retaining wall, and the one in (B) is an inverted trapezoidal gravity retaining wall. Yes, the one in (C) is a leaning type retaining wall, and the one in (D) is an L-shaped retaining wall. On the other hand, in the block stacking retaining walls 1B shown in FIGS. 11A to 11D, the one in (A) is a trapezoidal gravity retaining wall, and the one in (B) is an inverted trapezoidal gravity retaining wall. The wall (C) is an upright gravity retaining wall, and the one (D) is a leaning gravity retaining wall. The retaining walls 1A and 1B shown in FIGS. 10A to 10D and FIGS. 11A to 11D are representative, and there are various forms in addition to these. However, the description is omitted here. Further, in FIGS. 10A to 10D and FIGS. 11A to 11D, reference numeral 10 is a foundation concrete placed on the ground 2, and in many cases, the retaining walls 1A and 1B are respectively. It is built on the foundation concrete 10.

Among the various types of retaining walls described above, the applicant has referred to Japanese Patent Application Laid-Open No. 2003-286730 as a retaining wall similar to the inverted trapezoidal block-stacked retaining wall 1B exemplified in FIG. 11 (B). The one described in Document 1) is proposed.

By the way, regarding the retaining wall for retaining the earth, safety measures are required for the sliding property due to the earth pressure on the back side of the retaining wall and the sinking property due to the weight of the retaining wall itself. As an example, it is inspected whether the ground bearing capacity of the retaining wall construction site is higher than the required (safety) strength for the retaining wall to be constructed, and if the ground bearing capacity does not reach the required strength, the ground is reinforced. Construction will be carried out. The sliding power and subsidence force of the retaining wall may increase due to the occurrence of an earthquake, vibration caused by a passing vehicle, etc., and the required ground bearing capacity may be calculated in consideration of these external forces.

However, in order to perform the ground bearing capacity inspection for retaining wall construction with high accuracy, use inspection equipment with high functionality or make the ground inspection points dense (inspect many places at short intervals). However, there is a problem that the inspection equipment is expensive and the inspection takes a long time, which is a factor of increasing the cost as a result.

Therefore, in the past, the ground bearing capacity inspection at the retaining wall construction site was not performed with high accuracy to ensure safety in many cases, but it was unexpectedly performed about. be. Especially in the case of retaining walls constructed over a very long distance, such as retaining walls for roads in mountainous areas, ground bearing capacity surveys are conducted at points at considerable intervals in the direction of retaining wall construction. This is customary, and it is expected that there will be places where the ground bearing capacity does not reach the required strength within the range where the ground bearing capacity survey has not been conducted. The required strength of the ground bearing capacity includes the weight per unit area of the retaining wall and the resultant force based on the earth pressure from the back side of the retaining wall (in addition to this, vibration due to earthquakes and passing vehicles, load due to vehicles, etc. are taken into consideration. It is required to be at least three times as much as (in some cases).

On the other hand, in the conventional retaining wall structure, as illustrated in (A) to (D) of FIG. 10 and (A) to (D) of FIG. 11, the back side of the retaining wall is exemplified. The fact is that no special safety (deterrence) measures have been taken against slipperiness due to earth pressure and subsidence due to the weight of the retaining wall.

Japanese Patent Application Laid-Open No. 2003-286730

Retaining walls for retaining walls are required to ensure safety in terms of slipperiness due to earth pressure on the back side of the retaining wall and subsidence due to the weight of the retaining wall itself. As mentioned above, the ground bearing capacity inspection in Japan is unexpectedly performed about in terms of accuracy, and there may be places where the ground bearing capacity does not reach the required strength in a wide range of retaining wall construction sites. is expected.

On the other hand, in the conventional retaining wall structure, as illustrated in (A) to (D) of FIG. 10 and (A) to (D) of FIG. 11, sliding due to earth pressure on the back side of the retaining wall is performed. The fact is that no special safety (deterrence) measures have been taken against the nature and subsidence due to the weight of the retaining wall.

Therefore, in the conventional retaining wall structure, due to the uncertainty of the ground bearing capacity and the lack of anti-slip and subsidence measures for the retaining wall as described above, the constructed retaining wall has slipperiness and subsidence. In that respect, it could not be said that the reliability was sufficient.

Therefore, according to the present invention, even if the ground bearing capacity at the retaining wall construction site is not sufficiently reliable, the retaining wall can be prevented from slipping, sinking, falling, etc. by a relatively simple method. It was made for the purpose of providing a retaining wall construction method that could be complemented.

The invention of the present application has the following configuration as a means for solving the above problems. The invention of the present application is intended for a retaining wall construction method implemented at a retaining wall construction site.

[Invention of claim 1 of the present application]
The retaining wall construction method of the invention of claim 1 of the present application uses a large number of piles buried straddling the ground of the retaining wall construction site and the retaining wall constructed on the ground, and the retaining wall in the above ground. At each position with a predetermined interval in the construction direction, push the lower side of each of the above piles into the ground with a predetermined pushing force, and push the lower part of the pile to a depth where each of the above piles does not enter the ground any more due to the resistance of the ground. Each of the above by embedding the lower part of the pile and the upper part of each pile exposed on the ground in each pile after embedding the lower part of the pile in the ground with the ready-made concrete that constitutes a part of the retaining wall. It is characterized by performing a pile upper fixing step of fixing the pile upper part to the concrete body of the retaining wall. In the following description, the position where each pile is installed on the ground may be referred to as the pile installation position.

The pile used in the retaining wall construction method of the present application is buried straddling the ground and the retaining wall, and functions as an anchor to prevent the retaining wall from slipping, sinking, or tipping over. be. The pile is installed by pushing the lower part of the pile into the ground from above the ground to a predetermined depth, has a predetermined length (for example, usually 50 cm to 100 cm, and a long one is 100 cm to 150 cm) and has a predetermined break. Steel materials with an area (H-shaped steel, L-shaped steel, round pipes, square pipes, etc.) can be used. The pile material used in the present application may be any material that is strong in compressive force from the length direction, and for example, a concrete pile or a resin pile may be used instead of the steel material.

In the retaining wall construction method of the invention of claim 1 of the present application, in the pile lower part embedding step, the lower side of each pile is placed at each pile installation position at a predetermined interval in the retaining wall construction direction in the ground of the retaining wall construction site. It is installed by pushing it into the ground, but the interval between the pile installation positions is, for example, about 1 m to 2 m.

As a power source for pushing piles, for example, an excavation excavator used at a construction site can be used. When this excavation excavator is used, the excavator portion is placed on the upper end of the pile and the excavator portion is pushed downward by hydraulic pressure to generate a pushing force into the ground against the pile. Further, when a single excavation excavator is used, the pushing force to the pile can be made constant (for example, a constant pushing force of about 1 ton) every time. The pushing force against the pile can be increased or decreased depending on the scale of the retaining wall to be constructed (retaining wall weight per unit area). For example, a small-scale retaining wall (retaining wall weight per unit area is light) is constructed. An excavation excavator having a small pushing force (for example, a constant pushing force of about 0.5 tons) can be used at the place where the pushing force is applied.

Then, in the above-mentioned pile lower embedding step, the lower side of each pile is pushed into the ground with a predetermined (constant) pushing force at each pile installation position, and each pile does not enter the ground any more due to the resistance of the ground. The lower part of the pile is embedded to the depth, but the depth at which each lower part of the pile is embedded in the ground depends on the condition of the ground at each pile installation position. In other words, the ground at each pile installation position is constant at each pile installation position because the resistance of the ground that blocks the entry of the lower part of the pile differs depending on the hardness of the soil and the depth to the support layer (rock). The ground entry depth of each pile when the pile is pushed by the pushing force is different. At this time, the exposed length of the upper part of the pile exposed on the ground in each pile that pushed the lower part of the pile into the ground will be different, but even if the exposed length of the upper part of the pile is different, these exposed parts will be later. Since it is embedded in the concrete body in the pile upper fixing process, no problem occurs.

In places where the entire length of the pile is buried in the ground (where the ground bearing capacity is weak) when the pile is pushed into the ground with the above constant pushing force, the pile buried in the ground is invalidated. In the vicinity, another pile longer than the previous buried pile (pile with a length that reaches the support layer is preferable) should be pushed into the ground again.

By the way, in a state where the lower part of the pile is embedded to a depth where each pile does not enter the ground any more due to the resistance of the ground due to the pushing force, a bearing force from the ground corresponding to the pushing force is generated in the pile. The bearing capacity of this ground serves as a function to prevent the sinking of the retaining wall, which will be described later.

Further, by pushing each pile to a depth that does not enter the ground any more by the resistance of the ground in this way, the bearing capacity (hardness) of the ground can be investigated by the pushing depth of the pile.

On the other hand, in the retaining wall construction method according to claim 1 of the present application, the pile upper fixing step is performed after the above-mentioned pile lower part embedding step, and this pile upper fixing step is performed on each pile after the pile lower part is embedded in the ground. The upper part of each pile exposed on the ground is fixed to the concrete body of the retaining wall by hardening the upper part of each pile with the ready-mixed concrete that constitutes a part of the retaining wall.

In other words, when this pile upper fixing process is performed, each pile upper part is fixed in the concrete body (solidified concrete) that constitutes a part of the retaining wall, so that each pile upper part is integrated with the retaining wall. Will be combined with.

Therefore, a part of the weight of the retaining wall is supported by the ground through each pile, but since each pile is held by the supporting force from the ground corresponding to the pushing force, the retaining wall sinks. There is a function to prevent it from happening.

Further, in the retaining wall structure in which the retaining wall construction method of claim 1 is implemented, piles are interposed between the ground and the retaining wall, so that the retaining wall is prevented from sliding with respect to the ground. There is also a function to prevent the retaining wall from tipping over.

[Invention of claim 2 of the present application]
In the invention of claim 2 of the present application, in the retaining wall construction method of claim 1, the pushing force of the pile into the ground in the pile lower part embedding step is reached by the hard support layer in which the lower end of the pile is in the ground. The feature is that it is set to a strength that can be pushed in.

The hard support layer in the ground, also called bedrock, is very hard, and when the lower end of the pile is pushed into the ground until it reaches the support layer, it is larger than the pile from above. Even if a load (pushing force) is applied, the pile does not enter the ground any more, so that the bearing force on the ground side with respect to the pile is very large.

Also in the case of claim 2, when the pile is pushed into the ground with a large pushing force, in a place where the entire length of the pile is buried in the ground (a place where the ground bearing capacity is weak), the pile is in the ground. It is advisable to invalidate the buried pile and push another pile longer than the previous buried pile (a pile long enough to reach the support layer) into the ground again in the vicinity.

[Effect of the invention of claim 1 of the present application]
In the retaining wall construction method of the invention of claim 1 of the present application, a pile is pushed into the ground of the retaining wall construction site with a predetermined pushing force, and the lower part of the pile is pushed to a depth where the pile does not enter the ground any more due to the resistance of the ground. After embedding and embedding the lower part of the pile in the ground, the upper part of each pile exposed on the ground in each pile is solidified with the ready-mixed concrete that forms part of the retaining wall, so that the upper part of each pile is in the concrete body of the retaining wall. It is designed to be fixed to the concrete.

In this way, the piles embedded in the ground generate a fairly strong bearing capacity due to the ground, while the upper part of the pile is fixed in the concrete body of the retaining wall, so that the weight of the retaining wall is in the ground through the pile. Be supported.

Therefore, when the retaining wall construction method of claim 1 is implemented, the function of suppressing the retaining wall from subsidence in the ground can be complemented, while the retaining wall is interposed between the retaining wall and the ground. It is possible to achieve various effects such that the function of suppressing the sliding of the retaining wall against the ground and the function of suppressing the retaining wall from tipping over can be complemented.

Further, in the retaining wall construction method of claim 1, it is called a step of pushing the lower part of the pile into the ground (step of embedding the lower part of the pile) and a step of fixing the upper part of the pile to the retaining wall with ready-mixed concrete (step of fixing the upper part of the pile). By implementing a relatively simple method, there is an effect that the above-mentioned retaining wall subsidence suppressing function, retaining wall slip suppressing function, and retaining wall fall suppressing function can be complemented easily and inexpensively.

Further, as in claim 1 of the present application, pushing each pile to a depth that does not enter the ground any more due to the resistance of the ground makes it possible to investigate the supporting force (hardness) of the ground by the pushing depth of the pile. In addition to the above-mentioned retaining wall subsidence prevention function, retaining wall slip prevention function, and retaining wall fall prevention function, it also has the effect of being able to be used as a survey of ground bearing capacity.

[Effect of the invention of claim 2 of the present application]
In the invention of claim 2 of the present application, in the retaining wall construction method of claim 1, the pushing force of the pile into the ground in the pile lower embedding step is applied until the lower end of the pile reaches the hard support layer in the ground. Since the strength is set so that it can be pushed in, the lower end of the pile can be surely pushed in until it reaches the support layer.

Therefore, in the retaining wall construction method of claim 2, the pile is supported more firmly in the ground (the pile does not sink), so that in addition to the effect of claim 1, the retaining wall slides and sinks. And further deterrent effect can be achieved against the overturning action.

It is explanatory drawing of the pile lower part embedding process in the retaining wall construction method of the embodiment of this application. It is sectional drawing of the pile lower part embedded state in the retaining wall construction method of the Example of this application (the figure corresponding to the arrow II-II of FIG. 1). It is sectional drawing of the state which the foundation concrete was placed on the ground from the state of FIG. It is explanatory drawing at the time of constructing a trapezoidal gravity type retaining wall by cast-in-place from the state of FIG. It is a VV arrow view of FIG. It is explanatory drawing when constructing a trapezoidal gravity type retaining wall by block stacking from the state of FIG. It is a VII-VII arrow view of FIG. (A) to (D) are cross-sectional views of each of the in-situ retaining walls (4 types) constructed by implementing the retaining wall construction method of the embodiment of the present application. (A) to (D) are cross-sectional views of block stacking retaining walls (4 types) constructed by implementing the retaining wall construction method of the embodiment of the present application, respectively. (A) to (D) are cross-sectional views of each of the conventionally constructed in-situ retaining walls (4 types). (A) to (D) are cross-sectional views of block stacking retaining walls (4 types) that have been conventionally constructed.

[Example]
1 to 7 show each step of the retaining wall construction method performed in the embodiment of the present application, and FIGS. 8A to 8D show typical construction methods of the retaining wall construction method of the embodiment of the present application. Four types of in-situ retaining walls 1A are shown, and FIGS. 9A to 9D show typical four types of block-stacked retaining walls 1B constructed by the retaining wall construction method of the embodiment of the present application.

By the way, regarding the retaining wall for retaining the soil, safety measures are required for the sliding property due to the earth pressure on the back side of the retaining wall and the sinking property due to the weight of the retaining wall itself. The retaining wall construction method can construct a retaining wall structure that can exert effective deterrence against the sliding property, sinking property, and tipping property of the retaining wall by a relatively simple method.

Then, in the retaining wall construction method of the embodiment of the present application, as shown in FIGS. 1 to 9, the retaining wall is straddled between the ground 2 at the retaining wall construction site and the retaining wall (1A, 1B) constructed on the ground. A large number of piles 3 to be buried are used. The pile 3 is buried straddling the ground 2 and the retaining wall (1A, 1B), and functions as an anchor for preventing the retaining wall from sliding, sinking, or tipping over.

In the retaining wall construction method of this embodiment, H-shaped steel having a predetermined length (for example, usually 50 cm to 100 cm, and a long one 100 cm to 150 cm) and having a predetermined cross-sectional area is adopted as the pile 3. The size of the end face of the pile 3 (H-shaped steel) is not particularly limited, but may be about 10 cm on a side. When H-shaped steel is used as the pile 3, the wall thickness of the H-shaped steel is about 5 to 6 mm, and when the pile 3 (H-shaped steel) is pushed into the ground, it depends on the hardness of the ground. It can be pushed into the ground 2 with a pushing force of about 5 to 1.0 tons. In addition to the H-shaped steel, steel materials such as L-shaped steel, round pipes, and square pipes can be used as the pile 3, and concrete piles and resin piles can be used instead of the steel materials.

Then, in the retaining wall construction method of the embodiment of the present application, a large number of the above piles 3 are used, the pile lower part embedding process shown in FIGS. 1 to 2, the foundation concrete placing process shown in FIG. 3, and FIGS. 4 to 4 to FIG. 5 or the pile upper fixing step shown in FIGS. 6 to 7 is sequentially performed, and each of these steps will be described in detail below.

In the pile bottom embedding process, as shown in FIG. 1, at each position P, P ... The lower side (pile lower part 31) of each pile 3, 3 ... Is pushed into the ground 2 with a predetermined pushing force F, respectively. In the following description, each position P, P ... In which the pile 3 is pushed in the ground 2 may be referred to as a pile installation position.

As a power source for pushing the pile 3 into the ground 2, for example, an excavation excavator often used at a construction site can be used. When using this excavation excavator, the excavator portion is placed on the upper end of the pile 3 and the excavator portion is pushed downward by hydraulic pressure to generate a pushing force F into the ground 2 with respect to the pile 3. Can be done. At this time, if a single excavation excavator is used, the pushing force F with respect to the pile 3 can be made constant every time. The magnitude of the pushing force F with respect to the pile 3 can be increased or decreased depending on the scale of the retaining wall to be constructed (retaining wall weight per unit area), and is large (the retaining wall weight per unit area is large). In the case where the retaining wall is constructed, a small-scale retaining wall (the weight of the retaining wall per unit area is light) is constructed by using an excavation excavator having a large pushing force F (for example, a pushing force of about 1 ton). An excavator for excavation having a small pushing force F (for example, a pushing force of about 0.5 tons) can be used.

In the pile lower part embedding process, as shown in FIGS. 1 to 2, the lower side of each pile 3, 3 ... At each pile installation position P, P ... The pile bottom 31 is embedded to a depth where each pile 3, 3 ... does not enter the ground 2 any more due to the resistance of the ground 2, but when the pile 3 is pushed to a depth where it does not enter the ground any more. , An approach deterrent force corresponding to the pushing force F by the ground 2 is generated for the pile 3.

Further, when the pile 3 is pushed into the ground 2 by the predetermined pushing force F, the depth at which each pile lower portion 31 is embedded in the ground 2 differs depending on the state of the ground at each pile installation position P, P. That is, the ground at each pile installation position P, P ... has different resistance to prevent the entry of the pile lower portion 31 due to the difference in the hardness of the soil 21 and the depth to the support layer (hard bedrock) 22. In addition, the ground entry depth of each pile 3, 3 ... when the pile 3 is pushed with a constant pushing force F at each pile installation position P, P ... is different. At this time, the exposed lengths of the pile upper portions 32 exposed on the ground 2 in the piles 3, 3 ... In which the pile lower portion 31 is pushed into the ground 2 are different, but these pile upper portions 32, 32 ... As shown in FIGS. 5 and 7, the exposed portion of the above is not particularly problematic because it is completely embedded in the concrete body 12 later. If the exposed lengths of the upper parts 32, 32, ... Of the piles are significantly different, the exposed parts may be cut at a predetermined height position to make the exposed heights uniform.

By the way, each pile 3, 3 ... Used in a single retaining wall construction site is basically one having a constant length (for example, 1 m length) in sequence, but the pile 3 has a constant pushing force F. In a place where the entire length is buried in the ground 2 (the ground bearing capacity is weak and the lower end 3a of the pile is up to the support layer 22), for example, the pile 3 at the left end position in FIG. In places where it does not reach), the pile 3 buried in the ground is invalidated, and another pile 3'(preferably having a length of reaching the support layer 22) longer than the previous buried pile (for example, 1 m in length) is provided in the vicinity thereof. It is advisable to push the pile) into the ground again.

As shown in FIG. 2, the ground 2 often has a support layer (very hard bedrock) 22 under the soil 21, but since this support layer 22 is very hard, the pile 3 is subjected to a predetermined pushing force F. When the lower end 3a of the pile 3 reaches the support layer 22 when the lower end side of the pile 3 is pushed into the ground 2, the pile 3 cannot enter the ground 2 any more. Therefore, for the pile 3 embedded in the ground until the lower end 3a reaches the support layer 22, the resistance force of the ground (pile entry deterrence) becomes very large, and as will be described later, a large downward load is applied to the pile 3. Even if it works, it can prevent further entry into the ground. In claim 2 of the present application, it is specified that the lower end 3a of the pile 3 is pushed into the support layer 22 of the ground 2 until the lower end 3a of the pile 3 reaches the support layer 22 of the ground 2. In this way, the lower end 3a of the pile 3 is specified. When the pile reaches the support layer 22, the sinking deterrent to the pile 3 becomes very large, and as will be described later, it becomes a large deterrent to the sinking force due to the weight of the retaining wall itself.

By the way, if the scale of the retaining wall to be constructed is relatively small (the weight of the retaining wall per unit area is small), the bearing capacity of the ground may not be so large, but in that case, it is pushed into the pile 3. The force F may be reduced according to the scale of the retaining wall (for example, a pushing force of about 0.5 tons may be used). If the pushing force F with respect to the pile 3 is reduced, the pile 3 may not enter any more due to the resistance force in the ground 2 before the lower end 3a of the pile 3 reaches the support layer (hard rock) 22 of the ground 2. However, at that time, the pushing into the pile 3 may be stopped when the approach of the pile 3 is stopped.

When the lower end 3a of the pile 3 does not reach the support layer 22, the deterrent force against the pile 3 is smaller than that when the lower end 3a of the pile reaches the support layer 22, but the lower end 3a of the pile 3 becomes the support layer 22. Even in a state where it does not reach (only the supporting force to the pile 3 by the resistance force of the ground 2), a certain degree of subsidence suppressing effect can be exhibited. When the pile is installed in a state where the lower end 3a of the pile 3 does not reach the support layer 22 (a state in which the subsidence deterrent force for the pile 3 is small), the scale of the retaining wall is small and the bearing capacity of the ground is small as described above. Can be applied when is not required to be very large.

After the pile lower part 31 is embedded in the ground 2 at each pile installation position P, P ... (the pile lower part embedding process is completed in FIG. 2), the foundation concrete 10 is placed on the ground 2 as shown in FIG. The ready-mixed concrete, which is the foundation concrete 10, is integrally solidified at the bases of the upper parts 32, 32, ... Of each pile exposed from the ground 2. At this time, since the foundation concrete 10 has a relatively small thickness (for example, a thickness of about 10 cm), the pile upper portions 32, 32 ... Exposed on the ground 2 are exposed above the upper surface of the foundation concrete 10. There are many things that are done. Since the foundation concrete 10 firmly fixes a part of each pile 3,3 ... (the root portion of the pile upper portion 32), the foundation concrete 10 part sinks through each pile 3,3 ... Deterrence can be increased.

After placing the foundation concrete shown in FIG. 3, the exposed parts of the upper portions 32, 32 ... Of each pile exposed on the ground 2 (foundation concrete 10) as shown in FIGS. 4 to 5 or 6 to 7 are exposed. A pile upper fixing step of solidifying with ready-mixed concrete (solidified to become a concrete body 12) that constitutes a part of the retaining wall (1A, 1B) is performed. The working mode differs depending on whether the retaining wall 1A is the on-site retaining wall shown in FIGS. 8A to 8D or the blocking retaining wall 1B shown in FIGS. 9A to 9D.

When constructing each on-site retaining wall 1A shown in FIGS. 8A to 8D, the ground 2 (foundation concrete 10) is placed on the ground 2 (foundation concrete 10) at the retaining wall construction site as shown in FIG. ) Assemble the mold 18 so as to surround the upper portion 32 of each pile exposed above (assemble a predetermined length in the retaining wall construction direction), fill the mold 18 with ready-mixed concrete, and solidify it, as shown in FIG. As shown, the upper portions 32, 32, ... Of each pile exposed on the ground 2 (foundation concrete 10) are fixed to the concrete body 12 constituting a part of the retaining wall 1A.

Then, in order to construct the on-site retaining wall 1A having the required height as shown by the chain line in FIG. 4, the formwork 18'of the next stage is assembled on the concrete body 12 constructed as the first stage, and the formwork is assembled. The inside of 18'is filled with ready-mixed concrete 12'and solidified, and the in-situ retaining wall 1A is sequentially constructed to a desired height in the same manner.

The retaining wall construction examples of FIGS. 4 to 5 are for constructing the on-site retaining wall 1A of FIG. 8 (A), but other on-site retaining walls (those of FIGS. 8 (B) to (D)). Even so, various on-site retaining walls 1A can be constructed by performing almost the same steps as above (pile bottom embedding step, foundation concrete placing step, pile top fixing step). In each in-situ retaining wall 1A of FIG. 8, the one in (A) is a trapezoidal gravity retaining wall, the one in (B) is an inverted trapezoidal gravity retaining wall, and the one in (C). The one is a leaning type retaining wall, and the one in (D) is an L-shaped retaining wall.

By the way, in the L-shaped retaining wall 1A of FIG. 8D, since the bottom slab 1Aa is thin, a part of the pile upper portion 32 may protrude from the upper surface of the bottom slab 1Aa, and in that case, the exposure protruding from the upper surface of the bottom slab 1Aa. When the portion is hardened with ready-mixed concrete 12a, the adhesive force between the pile 3 and the retaining wall 1A can be increased.

On the other hand, when constructing the block stacking retaining wall 1B shown in FIGS. 9A to 9D, the ground 2 is placed on the ground 2 (foundation concrete 10) at the retaining wall construction site as shown in FIGS. 6 and 7. (Foundation concrete 10) Concrete blocks 13, 13 ... with hollow interiors are installed so as to surround the upper portions 32, 32 ... of each exposed pile (continuously for a predetermined length in the retaining wall construction direction), and each of them. By filling the internal vacant space of the concrete blocks 13, 13 ... with ready-mixed concrete and solidifying it, the upper part 32 of each pile exposed on the ground 2 (foundation concrete 10) as shown in FIGS. 6 to 7. 32 ... is fixed in the concrete body 12 that constitutes a part of the block stacking retaining wall 1B. The amount (filling height) of ready-mixed concrete (reference numeral 12) to be filled in the internal vacant space of the first-stage concrete block 13 is such that the pile upper portion 32 exposed on the foundation concrete 10 can be completely buried. It is preferable to fill up to, but any amount may be used as long as the filled ready-mixed concrete can firmly fix the pile upper portion 32 (can be integrated with the concrete block 13).

Then, in order to construct the block stacking retaining wall 1B having the required height, as shown in FIG. 6, the concrete block 13'of the next stage is stacked on the concrete block 13 containing the concrete body constructed as the first stage. The concrete block 13'is filled with the filler 14', and the block stacking retaining wall 1B is sequentially constructed to a desired height in the same manner. This block retaining wall 1B is also a gravity type retaining wall, and the filler 14 (or 14') filled in each concrete block 13 (or 13') may be soil, crushed stone, ready-mixed concrete, or the like as appropriate. Can be adopted. In addition, in the block stacking retaining wall 1B of the embodiment of FIGS. 6 to 7, soil is adopted as the filler 14 (or 14').

The retaining wall construction examples of FIGS. 6 to 7 are for constructing the block stacking retaining wall 1B of FIG. 9 (A), but other block stacking retaining walls (those of FIGS. 9 (B) to (D)). Even so, various block retaining walls 1B can be constructed by performing almost the same steps as above (pile bottom embedding step, foundation concrete placing step, pile top fixing step). In each block retaining wall 1B of FIG. 9, the one (A) is a trapezoidal gravity retaining wall, the one (B) is an inverted trapezoidal gravity retaining wall, and (C). The one is an upright gravity retaining wall, and the one in (D) is a leaning gravity retaining wall.

Examples of the retaining wall constructed by the retaining wall construction method of the embodiment of the present application include the in-situ retaining wall 1A shown in FIGS. 8 (A) to 8 (D) and the block stacking shown in FIGS. 9 (A) to 9 (D). There is a retaining wall 1B, but in these retaining wall structures, a large number of piles 3, 3 ... are interposed across the ground 2 and the retaining wall (1A, 1B), and each pile 3 is further connected. While it is held by a fairly strong bearing force from the ground 2 corresponding to the pushing force F, the pile upper portion 32 is integrally fixed to the concrete body 12 which is a part of the retaining wall.

Therefore, in the retaining wall structure constructed by the retaining wall construction method of the present application, a part of the weight of the retaining wall is supported by the ground 2 through the piles 3, 3, ... Therefore, each of the piles 3, 3 ... has a function of suppressing the retaining wall from sinking into the ground 2, and each pile 3, 3 ... straddles the ground 2 and the retaining wall. Since it is installed, there are also functions that can prevent the retaining wall from sliding with respect to the ground 2 and also prevent the retaining wall from tipping over.

Further, in the retaining wall construction method of the present application, it is called a step of pushing the pile lower part 31 into the ground 2 (pile lower part embedding step) and a step of fixing the pile upper part 32 to the retaining wall with ready-made concrete (pile upper part fixing step). With a relatively simple method, the sinking suppression function, the sliding suppression function, and the fall prevention function of the retaining wall can be complemented.

Further, as in the retaining wall construction method of claim 2 of the present application, the pushing force F of the pile 3 into the ground 2 in the pile lower part embedding step is applied to the hard support layer 22 in which the lower end portion 3a of the pile 3 is in the ground. When the strength is set so that the pile can be pushed in until it reaches the support layer 22, the lower end 3a of the pile can be surely pushed in until it reaches the support layer 22. A deterrent effect can be achieved.

In the embodiment of the present application, the foundation concrete 10 is placed on the ground 2 after the lower side of the pile 3 is pushed into the ground 2, but the foundation concrete 10 is not essential, for example. When constructing the in-situ retaining wall 1A, the retaining wall may be constructed directly on the ground 2 without placing the foundation concrete.

1A and 1B are retaining walls, 2 is the ground, 3 is the pile, 3a is the lower end of the pile, 10 is the foundation concrete, 12 is the concrete body, 13 is the concrete block, 14 is the filler, 18 is the mold, and 21 is the soil. 22 is the support layer, 31 is the lower part of the pile, 32 is the upper part of the pile, F is the pile pushing force, and P is the pile installation position.

Claims (2)

It is a retaining wall construction method implemented at the retaining wall construction site.
A large number of piles (3) buried straddling the ground (2) at the retaining wall construction site and the retaining wall (1A, 1B) constructed on the ground (2) were used.
At each position (P, P ...) with a predetermined interval in the retaining wall construction direction in the above ground (2), the lower side of each of the above piles (3, 3, ...) is grounded with a predetermined pushing force (F). (2) Pile bottom embedding step of embedding the pile bottom (31) to a depth where each of the above piles (3, 3, ...) Is pushed into the ground (2) and does not enter the ground (2) any more due to the resistance of the ground (2). When,
The upper part (32, 32 ...) of each pile exposed on the ground (2) in each pile (3, 3 ...) after the lower part (31) of the pile is embedded in the ground (2) is retained. The upper part of the pile (32, 32 ...) Is fixed to the concrete body (12) of the retaining wall (1A, 1B) by hardening with the ready-mixed concrete that constitutes a part of the wall (1A, 1B). Perform the fixing process,
Retaining wall construction method characterized by that. In the pile lower part embedding step, the pushing force (F) of the pile (3) into the ground (2) is provided, and the lower end portion (3a) of the pile (3) is a hard support in the ground (2). The strength is set so that it can be pushed in until it reaches the layer (22).
The retaining wall construction method according to claim 1, wherein the retaining wall is constructed.

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