JPS609615B2 - Early load loading soft ground compaction construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel load-bearing soft ground compaction construction method which is novel and of great industrial applicability.

Originally, civil engineering structures such as river embankments and coastal quays are large and heavy structures, so it is not desirable to build them on soft ground. It is not permissible to select sites for embankments, quays, etc. to avoid such problems, and as a practical matter, it is extremely often necessary to construct these types of wooden structures on soft ground.

In this case, it is absolutely necessary to implement a construction method that eliminates in advance the risks of water leakage from the foundation, subsidence of the structure, cracks and subsidence of the structure due to surrounding uplift or earthquakes. Despite this, none of the dependent methods can satisfy these conditions.

In other words, sand piles, which have been conventionally implemented as one of this type of construction methods, cannot be implemented on extremely soft ground due to their nature, and even on the ground where construction is possible, the ground cannot be sufficiently It is a well-known fact that it cannot be stabilized.

Another method is to excavate the viscous soil in soft ground and replace it with sandy soil, but in this method, after replacing it with sandy soil, it is left for a long period of time to wait for the ground to stabilize. The major drawback is that construction of the structure has to be started only after the construction has been completed.Furthermore, when dealing with soft underwater ground, many construction methods involve inserting sand mats and placing rubble after the viscosity has stabilized. However, this construction method not only takes a long time to stabilize the ground, but also the rubble often sinks into the soft ground, and the rubble collides with the stable ground and worships it. This method has the disadvantage of reducing the supporting force, and, in common with the above-mentioned conventional construction methods, it requires a great deal of effort and expense.

The purpose of the method of the present invention is to completely solve the problems of such conventional methods. Next, the configuration of the method of the present invention will be specifically explained with reference to the drawings showing one embodiment.

1...1 is a water-permeable fabric re-bag body used in the method of the present invention, which is shaped like a rectangular plate and has a concrete injection hole 2 in its surface.

The water-permeable cloth material forming the water-permeable cloth re-bag bodies 1...1 is selected from natural fiber cloth, synthetic fiber cloth, nonwoven fabric, etc. Preferably, it is made of a suitable material. In the method of the present invention, "a large number of water-permeable fabric re-bag bodies 11...1 having the above-mentioned configuration,
Concrete is poured into each bag, which is laid adjacent to cover the soft ground 3 at the construction target location, and then passed through the transport pipe 6 of the concrete plant 5 from the concrete plant 5 installed on the ground or on the carrier ship 4. Fresh concrete is injected into each permeable fabric regular bag body 1...1 through the hole 2.
The soil is filled and solidified as one, and the specific gravity of the soil is 1.
．． It is made into a concrete block containing concrete having a specific gravity of 2.4 to 6.

In this case, as shown in FIGS. 1 and 2, the water-permeable fabric purification bags 1, . . . Frame holding reinforcing bar 81・
08, and if the frame holding reinforcing bars 81. By filling, the water-permeable cloth purification bags 1, 0, 1 become reinforced concrete blocks whose shape is maintained in a rectangular flat plate by the iron frame 7 and the frame holding reinforcing bars 81...8, and the water-permeable cloth purification bags 1, Not only can the strength and compaction effect of the body 1 be increased, but also the water-permeable fabric remade bag body 1 is shaped like a rectangular flat plate.
. . . The reason why a large number of 1 are closely connected to each other without any gaps to form a group of permeable cloth bags that completely covers the soft ground 3 at the construction target location, making the effect of the method of the present invention even more remarkable. Therefore, it is suitable.

In addition, a connecting ring 9 is attached to an appropriate position of the iron frame 7 provided around the circumference of each water-permeable fabric re-bag body, and the connecting ring of adjacent water-permeable fabric bag bodies 1, 1 is attached via a connecting string 10. 9 are connected as shown in FIG. 2 to form a series of water permeable fabric remade bags 101
・If one group is formed, the loading of the water-permeable fabric re-wrapped bodies 11...I onto the soft ground 3 can be carried out quickly and orderly. Since it is related to the method of constructing things on soft ground, many re-made water-permeable cloth bags are used for the bottom of rivers and coasts.
・It is extremely effective considering that it is necessary to sink 1 one after another quickly and orderly.

In the method of the present invention, a load 12 of approximately the same weight as the target civil engineering structure 11 is loaded on one group of water-permeable fabric regular bags 1 made into concrete blocks as described above,
It is assumed that the soft ground 3 is consolidated, and then the load 12 is removed, and then the intended civil engineering structure 11 is constructed.

In this case, it is desirable that the loading of the load 12 be carried out sequentially by dividing it into several stages.

Originally, ``the present inventor refers to virgin ground that is naturally settled and has not been subjected to pre-consolidation loads (hereinafter referred to as unconsolidated ground).

) and ground that has been subjected to preconsolidation loading in the past (hereinafter referred to as overconsolidated ground), and as a result of repeated careful comparative experiments, it was found that In the Hagiwei experiment, the subsidence near the Hagi loading point was noticeable at each stage of the load intensity, whereas in the loading experiment on overconsolidated ground, the subsidence near the Hagi loading point was observed up to the preconsolidated load. They found that the amount of settlement was much smaller than that in unconsolidated ground even when a load higher than the consolidated load was applied. After the load 12 of approximately the same amount as the target civil engineering structure li is loaded on the first group and the soft ground 3 is consolidated, the load 12 is removed and the target civil engineering structure 11 is covered with a permeable cloth. We have completed the method of the present invention, which is characterized in that it is constructed on a group of remade bags 1...1.The following is an outline of an example of a load experiment on unconsolidated ground and overconsolidated ground. .

Experimental Example Sludge deposited at the bottom of the Yasu River in Shiga Prefecture was collected and the water content was adjusted to approximately 50%.The sample had the physical properties shown in Table 1 below. As shown in the figure, a sludge layer 14 is formed by filling the soil up to a height of 60 cm in an experimental land tank 13 with a width of 150 cm and a depth of 20 cm. A sand layer 15 is provided, and a dial gauge 6 as shown in the figure is provided as an experimental tank. Two of the experimental tanks are prepared, and each experimental tank is used for a Hagi load experiment on unconsolidated ground. (
Hereinafter, it will be referred to as Experimental Example 1.

) and a warload experiment (hereinafter referred to as Experimental Example 2) on overconsolidated ground was carried out at the load strength for each stage as shown in Table 2.Table 1 Note: % indicates weight %. Below, same)
.

Table 2 Namely, "In Experimental Example 1, as shown in Table 2 and FIG.
A locally uniformly distributed load of m was applied from the first stage to the fifth stage every 24 hours, after which the load was removed and left for 48 hours to examine swelling.

Next, in Experimental Example 2, the sand layer 15 in the experimental tank 13 is
An equal load corresponding to the third stage load of Experimental Example 1 was applied to the entire upper surface, and the ground was consolidated for 8 days to form overconsolidated ground.
Then, the uniformly distributed load was unloaded, and immediately after that, similarly to Experimental Example 1, the load experiment was conducted up to the 7th stage as shown in Table 2.
It was unloaded and left for 4 hours to check for swelling. The amount of displacement of the upper surface of the experimental tank 13 at the end of each load stage in Experimental Examples 1 and 2 above is shown in Tables 3-1 to 3-8 and Table 7 below.
As shown in Fig. 8.

Table 3-1 [Load stage 1 (Load strength: 0.024kg)] Table 3-2 [Load stage 2 (Load strength: 0.047K)
Table 3-3 [Load level 3 (Load intensity: 0.071 kg I slight) change * Positive amount] Table 3-4 [Load stage 4 (Load strength: 0.094 kg I) 3)
-5 [Load stage 5 (cargo room Silkworm Morika: 0.118kg Ison)
Table 3-6 [Load stage 6 (Load silkworm summer: 0.1
Table 3 River 7 [Load effect 7 (
Luggage space fatigue: o. Table 3
~8 [Load removal] Tables 3-1 to 3-8 above, as well as Figures 7 and 8, which illustrate an explanatory diagram of a load experiment on unconsolidated ground and an explanatory diagram of a clover droplet experiment on consolidated ground, respectively. In Experimental Example 1, the subsidence near the loading point increases as the load intensity increases, whereas in Experimental Example 2, the settlement at the third stage (load intensity: 0)
．． There was no noticeable displacement until 071k9, and the amount of subsidence decreased even in the subsequent stages.

In this case, the load strength of the third stage is 0.071 kg.
As mentioned above, it is equal to the pre-consolidation load applied evenly to the surface layer to create over-consolidated ground. It seems that the amount of settlement is small even if the load intensity exceeds the pre-load, but as the load increases, the amount of settlement gradually becomes similar to that of unconsolidated ground.

In addition, in both Experimental Example 192, although a rise can be seen in the vicinity of the loading point due to subsidence in the vicinity of the loading point, in the unconsolidated ground shown in Experimental Example 1, the fourth stage (load intensity:
On the other hand, in the compacted soil shown in Experimental Example 2, the load strength increases from the 6th stage (load strength: 0.141k9). It is also noteworthy that there is an increase in the area around the point. In the method of the present invention, ``Based on the above-mentioned new findings revealed by the present inventor in the above experimental example, the target civil engineering structure 11 is approximately Consolidating the soft ground 3 by loading the same amount of load 12, in other words, the soft ground 3 is an overconsolidated ground that hardly sinks under the load of the target ± wooden structure. After that, even if the load 92 is removed, the target structure 1 remains as a bag made of water-permeable cloth as shown in FIG.

It is constructed on the GG1 group. In addition, ``Figure 5'' shows that the invaginated part due to the consolidation of the soft ground S according to the method of the present invention is filled with sandy clay, and a water-permeable cloth re-bag body turtle G is further placed on top of the sandy soil.

This shows the state in which the 0th army is placed in battle.

The loading oven 2 used in the method of the present invention is the 4th choice from the viewpoints of ease of loading, conspicuousness of load effect, corrosion resistance, etc.
It is effective to use 1-section steel as shown in the figure.

The effects of the method of the present invention reside in the following points, as is clear from the aforementioned constitution 8 of the method of the present invention.

'ai Instead of transporting concrete blocks produced at a factory to a construction site and laying them, the water-permeable cloth bag body 1...1 having the above configuration is transported to the construction site and laid. After that, it is only necessary to fill each permeable cloth re-bag body 11...1 with ready-mixed concrete, which greatly contributes to speeding up the construction work and reducing costs.

{b) To form an overconsolidated ground that hardly sinks under the load of the target ± wooden structure 11 very easily, reliably, and quickly, and to build the ground so as to cover the overconsolidated ground. The civil engineering structure 11 is constructed on a group of strong rectangular flat concrete blocks or a group of rectangular flat reinforced concrete blocks, in other words, on a huge concrete slab laid on overconsolidated ground. Therefore, the advantages in this respect, such as the great consolidation effect, quick construction period, and low cost, are truly great, and as a method of constructing shingle on soft ground, it has special effects that are unparalleled in the past. has.

{c} Due to the structure of the transparent cloth bags 1...1, even in the case of underwater construction, which is generally difficult to perform, the transparent cloth bags 1...・Can form one group and prepare for continuous pouring of fresh concrete,
It is extremely effective in this respect as well.

[d) When the civil engineering structure 11 is a quay, if the first group of water-permeable fabric re-bags 11 laid adjacent to the quay are extended to some extent above the seabed in front of the quay, the scour prevention effect and wave dissipation effect can be improved. This is remarkable, as it eliminates the need to add blocks to the front of the quay, and the economic effect in that respect is significant.

[Brief explanation of the drawing]

Figures 1 to 5 all show one embodiment of the method of the present invention, and Figures 1 and 2 are respectively a perspective view of a water-permeable fabric purification bag used in the method of the present invention and a mutual relationship. FIG. 3 is an explanatory diagram showing the mode of pouring ready-mixed concrete into the permeable fabric bag body; FIG. 4 is a plan view showing how the permeable fabric bags are connected; FIG. 5 is a side view showing an aspect in which a heavy single-shaped steel is loaded, FIG. 5 is a side explanatory view showing an aspect in which a civil engineering structure is constructed by the method of the present invention, and FIG.
FIG. 7 is an explanatory diagram of the loading experiment equipment; FIG. 7 is an explanatory diagram of the loading experiment on unconsolidated ground; and FIG. 8 is an explanatory diagram of the loading experiment on overconsolidated ground. In the drawings, 1...1... Water-permeable fabric remade bag body, 2...
...Concrete injection hole, 3...Soft ground,
7... Steel frame 8... 8... Frame holding reinforcing bars, 11... ± wooden structure, 12... Load. Fig. 1 Fig. 2 Figure 3 Traditional map Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. Shape of a rectangular plate, with concrete injection holes 2 on the surface.
A large number of water-permeable fabric bags 1...1 that have been opened are laid adjacent to each other so as to cover the soft ground 3 at the construction target location, and fresh concrete is sequentially poured into the water-permeable fabric bags 1...1 through concrete injection holes 2. After injecting and filling, the target civil engineering structure 11 is placed on top of the water-permeable fabric bags 1...1 group, which are made into concrete blocks.
The soft ground 3 is consolidated by loading a load 12 of approximately the same weight as , and then the load 12 is removed to form the intended civil engineering structure 11.
An early load-bearing soft ground compaction construction method characterized by constructing on a group of water-permeable fabric bags 1...1. 2. Each of the water-permeable fabric bags 1...1 has an iron frame 7 around its peripheral edge, and within the water-permeable fabric bag 1, a plurality of frame holders connect the opposite sides of the iron frame 7. The early load-bearing soft ground compaction construction method according to claim 1, wherein reinforcing bars 8...8 are installed vertically and horizontally. 3. The early load carrying soft ground compaction construction method according to claim 1, wherein the load 12 is a large number of Type 1 steels.