JP2005068995A - Cutoff structure of joint of continuous underground wall and its construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutoff structure of a joint having a high practicability by enhancing workability, constituting a perfect cutoff performance in the joint in the construction method of a continuous underground wall by connecting a precedent element and a succeeding element by a joint and eliminating insufficient strength and preventing occurrence of troubles such as a flood accident, and its construction method. <P>SOLUTION: The cutoff structure of a joint for the continuous underground wall has a structure as described below. A precedent element with a specified width is excavated/constructed with a specified distance in the ground, Thereafter, a succeeding element 12 is excavated/constructed between the precedent elements 11 in the continuous underground wall. The precedent element 11 and the succeeding element 12 are constructed by use of soil cement. A notch 16a is formed in the precedent element 11 in the joint 21 of the succeeding element 12. A cutoff plate 20 is inserted in the notch 16a to proceed into the precedent element 11 and the succeeding element 12. The construction method to construct the structure as described above is employed as basic means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a water-stopping structure of a joint part for enhancing the water-stopping property of a connecting portion of each element in a construction method for constructing an underground continuous wall using soil cement, and a construction method thereof.

  Conventionally, in the cast-in-place pile method and other foundation work, as shown in the work state diagram of FIG. A means for carrying out excavation in the ground by the shell 9 by driving the shell opening / closing wire 8 by hanging the hammer grab 7 containing the weight with the suspended hanging wires 6, 6 and dropping it into the steel pipe 3 is performed. Yes.

  On the other hand, in the CRM method (Continuous walls using Recycled Mud), a multi-axis rotary excavator or bucket excavator is used to excavate and construct a predetermined element of a predetermined width in the ground, and then A method of excavating and constructing a trailing element between each preceding element is used. For example, as shown in FIG. 12, H-shaped steels 10 and 10 as the core material and soil cement are used to construct the preceding elements 11 and 11 in the excavation hole with a certain interval, and then as shown in FIG. After excavating similarly between the preceding elements 11, 11, H-shaped steels 10, 10 as the core material are built, and as shown in FIG. 14, soil cement is placed to construct the trailing element 12. FIG. 15 is a plan cross-sectional view of the main part of the completed part. The leading element 11 and the trailing element 12 are connected by a joint part 21, and a soil cement 18 around the H-shaped steels 10 and 10 as a core material together with both elements. The structure has been solidified by casting.

With respect to the above, Patent Document 1 discloses that when drilling the ground with an excavator for columnar walls, cement milk is discharged from the tip and mixed in the soil to form one element wall, and then each element wall In the soil column wall construction method, which wraps the wall, the core material to be built in the column wall is wide in the H-shaped steel flange on the planned drilling side, and joints on the left and right sides A soil column wall construction method in which the core members are formed and the flanges on the planned excavation side are connected via a joint is described.
JP-A-10-298975

  However, in the construction method in which the conventional leading element 11 and the succeeding element 12 are connected by the joint portion 21 to construct the underground continuous wall, there is a problem that the water stoppage failure and the strength are insufficient at the joint portion 21. In particular, if there is a water stop defect, there is a problem that a serious trouble such as a water outflow accident will occur after the completion of construction. Careful construction management is required while maintaining the strength of both elements. In addition, there is a means for removing the mud film and digging debris adhering to the joint part 21 by cleaning the joint part 21 when constructing the trailing element 12, but maintaining the water stoppage. It cannot be completely eliminated.

  In the soil column wall construction method described in Patent Document 1, H-shaped steel having a special shape must be used as a core material, and it is difficult to mesh the joints that connect the flanges to each other, resulting in poor workability. Therefore, there is a drawback that it lacks practicality.

  Therefore, in view of the above circumstances, the present invention makes it possible to completely prevent water shortage at the joint part in the construction method in which the preceding element and the succeeding element are connected by the joint part to construct the underground continuous wall and solve the lack of strength. An object of the present invention is to provide a water stop structure for a joint part of a continuous underground wall and its construction method that prevents the occurrence of troubles such as accidents, and improves the workability without using a specially shaped core material. It is what.

  In order to achieve the above object, the present invention provides an underground continuous wall in which a predetermined element is excavated and constructed with a predetermined interval in the ground, and then a subsequent element is excavated and constructed between each preceding element. The leading element and the trailing element are constructed using soil cement, and a notch is formed in the leading element at the joint with the trailing element, and both the leading element and the trailing element enter the notch. The water stop structure of the joint part of the underground continuous wall with the water stop plate inserted is provided.

  In addition, the core element is built in the hole by excavating the hole of the preceding element, the soil cement is placed in the hole, and the soil cement is solidified to the extent that it retains its shape before being excavated. At the same time as excavating the hole for the succeeding element in the part, or excavating the soil cement of the preceding element so as to be continuous with the hole of the succeeding element after excavation to form a notch, The core material is built in the hole of the element, and a water stop plate is inserted into the notch so as to enter both the preceding element and the succeeding element, and then soil cement is placed in the hole and notch of the succeeding element. Then, the water stop method for the joint part of the underground continuous wall that excavates and constructs the underground continuous wall is provided. And the notch part is formed in the both sides of a preceding element, and the soil cement casted in the preceding element and the succeeding element has meshed | engaged unevenly through the notch part.

  According to such a water-stopping structure of the joint part of the continuous underground wall and its construction method, the leading element and the trailing element are constructed using soil cement, and water is stopped on the left and right sides of the joint part of the leading element and the trailing element. By inserting the plate, the water stoppage at the joint part can be completely maintained and the strength can be improved to effectively prevent the occurrence of trouble such as a flood accident. Moreover, a core material or the like having a special shape is unnecessary, has high workability, and can provide a water-stopping structure for the joint portion of the underground continuous wall and its construction method, which are highly practical.

  The best mode for carrying out the present invention will be described below with the same reference numerals assigned to the same components as those of the conventional configuration. In the present invention, in the underground continuous wall construction method in which the succeeding element is excavated and constructed between the preceding elements, the leading element and the succeeding element are constructed using soil cement, and the joint between the preceding element and the succeeding element is stopped. By inserting the water plate, the water stoppage at the joint part is completely maintained and the strength is improved to prevent the occurrence of trouble such as a water discharge accident.

  As shown in FIG. 1, first, holes of the preceding elements 11, 11 having a predetermined width and a predetermined length are excavated, and H-shaped steels 10, 10 connected to each other as a core material are built in the holes. The closed region 16 is formed in the vicinity of the unexcavated portion 12a for the succeeding element in the hole, that is, between the H-shaped steel 10 as the core material of the preceding element 11 and the unexcavated portion 12a for the succeeding element. A waterstop plate mold 15 is installed. The waterstop plate mold 15 is a columnar body having a square cross-section or other appropriate shape, and has the same overall length as the depth of the hole of the preceding element 11. In addition, as shown in FIG. 1, the waterstop plate mold 15 is disposed at both ends of the hole of the preceding element 11. Or you may install two or more in the width direction.

  FIG. 2 shows the positional relationship between the H-shaped steels 10 and 10 and the waterstop plate mold 15 in the hole of the preceding element 11, and this waterstop plate mold 15 is not excavated for the preceding element 11 and the succeeding element. A space having a width W is formed between the joint portion 21 and the unexcavated portion 12a.

  Next, as shown in FIG. 3, the tremy pipe 17 is inserted into the hole of the preceding element 11, and the soil cement for reuse of excavated soil produced by a concrete mixer (not shown) is poured into the hole through the tremy pipe 17. To cast. FIG. 4 shows a state where the hole is filled with the soil cement 18 and the placement is completed.

  Then, after the soil cement 18 is solidified to the extent that it has shape retention, the waterstop plate mold 15 is pulled out from the state shown in FIG. 4 to form the closed region 16 shown in FIG. A soil cement 18 corresponding to the width W is also placed between the closed region 16 and the unexcavated portion 12a for the succeeding element.

  Thereafter, a hole for the succeeding element 12 is excavated in the unexcavated portion 12 a so as to be continuous with the closed region 16. That is, the soil cement 18 is overlapped with the previously placed preceding element 11 by an amount slightly wider than the width W shown in FIG. 5, and the hole for the succeeding element 12 is excavated. Therefore, the closed region 16 becomes a U-shaped notch 16a as shown in FIGS. 6, 7, and 8, and this notch 16a is continuous with the hole for the succeeding element 12. Next, after excavating the hole of the trailing element 12, the H-shaped steels 10 and 10 connected to each other are built as shown in FIG. 6, and the leading elements 11 and 11 are inserted into the notch 16a as shown in FIG. And the water stop plates 20 and 20 are inserted so as to straddle between the holes of the trailing element 12. The water stop plate 20 is in a position where the leading element 11 and the trailing element 12 enter both directions on the left and right sides of the joint portion 21.

  Next, a tremy pipe is inserted into the hole of the trailing element 12 in the same manner as described above, and a soil cement produced by a concrete mixer (not shown) is poured and placed. FIG. 9 and FIG. 10 show a state in which the soil cement 18 is filled in the hole of the succeeding element 12 and the placement is completed, and straddles the joint portion 21 between the preceding element 11 and the succeeding element 12. In this state, the water stop plate 20 is inserted into both the preceding element 11 and the succeeding element 12.

  Next, another embodiment of the present invention will be described. In this embodiment, the means for forming the notch 16a is different, and the other configuration is the same as that of the above-described embodiment. In this embodiment, without inserting the waterstop plate mold material 15, the H-shaped steel 10 as the core material is built in the hole portion of the preceding element 11, and the soil cement 18 is placed in the hole portion, After the 18 has solidified to such an extent that it retains its shape, the preceding element 11 is formed so as to be continuous with the hole of the succeeding element 12 simultaneously with the excavation of the hole for the succeeding element in the unexcavated portion or after excavation. The soil cement 18 is excavated to form a notch 16a. That is, the notch 16a shown in FIG. 8 is formed by directly excavating the soil cement 18 of the preceding element 11. The process after forming the notch 16a is the same as that of the above-mentioned embodiment.

  As described above in detail, according to the present invention, the water stoppage of the joint portion of the preceding element and the succeeding element can be increased, the strength is improved, and the occurrence of trouble such as a flood accident is prevented, and It is possible to provide a water stop structure and its construction method for the joint part of the underground continuous wall that is highly practical and has high workability.

The principal part perspective view which shows embodiment of this invention. The principal part top view of FIG. The principal part perspective view which shows the implementation process of this invention. The principal part perspective view which shows the implementation process of this invention. The principal part cross-sectional view which shows the implementation process of this invention. The principal part perspective view which shows the implementation process of this invention. The principal part perspective view which shows the implementation process of this invention. The principal part cross-sectional view which shows the implementation process of this invention. The principal part perspective view which shows the implementation process of this invention. The principal part plane sectional view of the completed underground continuous wall. Work state diagram in foundation work such as cast-in-place pile method. The principal part perspective view for demonstrating the conventional CRM construction method. The principal part perspective view which shows the process of the next step of FIG. FIG. 14 is a main part perspective view showing a step subsequent to FIG. 13. The principal part plane sectional view of the underground continuous wall by the conventional CRM method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... H-shaped steel 11 ... Leading element 12 ... Subsequent element 12a ... Unexcavated part 15 ... Molding material for water stop board 16 ... Blocking region 16a ... Notch part 17 ... Tremy pipe 18 ... Soil cement 20 ... Water stopping board 21 ... Joint part

Claims (7)

  In the underground continuous wall where excavation / construction of the leading element of a predetermined width is established in the ground with a certain interval, and then the succeeding element is excavated / constructed between each preceding element, the leading element and the trailing element are soil cement. The water stop structure of the joint part of the underground continuous wall, characterized in that the water stop plate is inserted into the joint part of the preceding element and the succeeding element.   In the underground continuous wall where excavation / construction of the leading element of a predetermined width is established in the ground with a certain interval, and then the succeeding element is excavated / constructed between each preceding element, the leading element and the trailing element are soil cement. Of the joint part of the underground continuous wall, characterized in that a water stop plate is inserted into the joint part of the preceding element and the succeeding element so as to enter both the preceding element and the succeeding element. Water stop structure.   In the underground continuous wall where excavation / construction of the leading element of a predetermined width is established in the ground with a certain interval, and then the succeeding element is excavated / constructed between each preceding element, the leading element and the trailing element are soil cement. It is constructed using the, and a notch is formed in the preceding element in the joint part with the succeeding element, and the water stop plate is inserted into the notched part so as to enter both the preceding element and the succeeding element. The water stop structure of the joint part of the underground continuous wall that is characteristic. In the underground continuous wall method of excavating and constructing a leading element of a predetermined width with a certain interval in the ground, and then excavating and constructing a trailing element between each preceding element,
Drill the hole of the preceding element, place the soil cement in the hole, solidify the soil cement to a shape retaining property, and then drill the hole for the succeeding element in the unexcavated part. At the same time, or after excavation, the soil cement of the preceding element is excavated so as to be continuous with the hole of the succeeding element, so that a notch is formed, and both the preceding element and the succeeding element enter the notch. A water stop method for the joint part of the underground continuous wall, in which the underground continuous wall is excavated and built by inserting soil cement into the hole and notch part of the succeeding element after inserting the water stop plate into the bottom. In the underground continuous wall method of excavating and constructing a leading element of a predetermined width with a certain interval in the ground, and then excavating and constructing a trailing element between each preceding element,
Drilling the hole of the preceding element and building the core material in the hole, placing the soil cement in the hole, solidifying the soil cement to a shape retaining property, At the same time as excavating the hole for the succeeding element or after excavation, the soil cement of the preceding element is excavated so as to be continuous with the hole of the succeeding element to form a notch. The core material is built in the part, and the water stop plate is inserted into the notch part so as to enter both the preceding element and the succeeding element, and then soil cement is placed in the hole and notch part of the succeeding element. A water stop method for joints of underground continuous walls, characterized by excavating and building underground continuous walls.   The water stop construction method of the joint part of the underground continuous wall of Claim 4 or 5 which formed the notch part in the both sides of the preceding element.   The water stop method of the joint part of the underground continuous wall according to claim 4, 5 or 6, wherein the soil cement casted on the preceding element and the succeeding element is meshed in an uneven shape through the notch part.

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