JP5367537B2 - Construction method and structure of steel pipe sheet pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for constructing steel pipe sheet piles with excellent work efficiency, which drives and fixes the steel pipe sheet piles into the ground even on the soft ground on the base rock, and to provide a structure using the same. <P>SOLUTION: Super-setting delay mortar 15 used as a sediment support member is filled in a casing 11a (in a hole 13a) while pulling out the casing 11a from the hole 13a. The super-setting delay type mortar 15 is filled close to a boundary between the base rock 3b and the soft ground 3a. Each steel pipe sheet pile 5a is formed in a position held between super-setting delay mortar filling parts, and each steel pipe sheet pile 5b is installed in the super-setting delay mortar filling part in a position held between the steel pipe sheet piles 5a. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a steel pipe sheet pile construction method and a structure using the steel pipe sheet pile, which are particularly suitable when soft ground such as earth and sand is deposited on a rock that is a hard ground.

  Conventionally, in the case of ground only with rocks where the ground does not collapse, in order to place steel pipe sheet piles, the ground was drilled using an all-around rotary excavator using a casing, and the casing was extracted. Later, a method is adopted in which steel pipe sheet piles are sequentially installed by inserting the steel pipe sheet piles into the holes. The steel pipe sheet pile is fixed with mortar or the like filled in a gap with the ground. At this time, adjacent steel pipe sheet piles are installed by fitting joints provided on the side of the steel pipe sheet piles to each other. Therefore, it is necessary to drill a hole having an outer diameter into which the steel pipe sheet pile including the joint portion can be inserted into the ground.

  On the other hand, depending on the ground, a sedimentary layer (soft ground) such as sedimentary earth and sand may exist on the rock which is a hard ground to which the steel pipe sheet pile can be fixed. In this case, if a steel pipe sheet pile is to be placed by the same method, when the casing is pulled out, earth and sand in the upper deposited layer may flow down into the hole and fill the hole. In order to prevent this, sand or the like is thrown into the hole drilled by an all-around rotary excavator or the like while pulling out the casing to prevent natural ground collapse. However, sand or the like thrown into the hole formed in the rock portion has no escape around the insertion of the steel pipe sheet pile from above, and the sand or the like is further tightened, making insertion difficult. Moreover, even if it can insert, it is difficult to fill cement milk etc. around a steel pipe sheet pile after that, and it is difficult to fix a steel pipe sheet pile to the ground.

  As a method for preventing the inflow of earth and sand after drilling into the hole, for example, a foundation pile is inserted into the casing in the excavation hole, and a filler is filled between the foundation pile and the casing. After that, there is a construction method of a foundation pile that raises the casing (Patent Document 1).

  Further, there is a method in which after drilling a rock layer with an all-around rotary excavator, the casing is pulled out and clay mortar is filled in the excavation hole (Patent Document 2).

JP 62-6023 JP 2002-201635 A

  However, the method described in Patent Document 1 only needs to be installed alone like a foundation pile, but when steel pipe sheet piles adjacent to each other need to be joined together by a joint like a steel pipe sheet pile. In the first place, since the casings overlap each other, it is impossible to fit and install adjacent steel pipe sheet piles before removing the casings.

  Moreover, in the method like patent document 2, since clay mortar is replaced with a casing, earth and sand etc. do not flow into the filled clay mortar part, but clay mortar is weak in the first place, and a steel pipe sheet pile is used. Insufficient strength to fix to bedrock. On the other hand, filling with high strength mortar is not desirable because the steel pipe sheet pile itself cannot be inserted.

  The present invention has been made in view of such a problem, and even when soft ground exists on the rock, a steel pipe sheet pile can be placed and fixed to the ground, and has excellent workability. An object of the present invention is to provide a construction method and a structure using the construction method.

In order to achieve the above-mentioned object, the first invention is a method for constructing a steel pipe sheet pile, the step (a) of forming a first hole in the ground using a casing in a post-punched steel pipe sheet pile placing scheduled portion; The step (b) of pulling out the casing from the first hole and providing an earth and sand support member inside the first hole, and placing the steel pipe sheet pile adjacent to the post-cast steel pipe sheet pile placing scheduled portion A step (c) of forming a second hole in the ground so that the end of the first hole overlaps with the first hole using a casing in the planned portion; and a steel pipe sheet pile in the casing inside the second hole. A step (d) of installing, filling the first mortar into the gap between the steel pipe sheet pile and the casing and the inside of the steel pipe sheet pile, and pulling out the casing from the second hole; and the first hole Against the earth and sand support member inside Was provided with the step of pouring (e), the said soil supporting member is a super-retarding type mortar with setting retardation property, the ultrasonic coagulation delayed mortar, gluconic acid 0 as retarding material. The steel pipe sheet pile construction method is characterized in that it is added in an amount of 3 to 1.5% and does not start the setting of the super setting delay type mortar during the step (c) and the step (d) . In this case, the ultra-set delay mortar has a set delay of more than twice the number of days required for the step (c) and the step (d), and the final compressive strength is 10 N / mm ² or more. In addition, aggregates for post-coating steel sheet piles and thickeners may be added to the super-set delay type mortar.

2nd invention is the construction method of a steel pipe sheet pile, Comprising: The process (a) which forms a 1st hole in the ground using a casing in a post-punching steel pipe sheet pile installation scheduled part, and a casing from said 1st hole And a step (b) of providing an earth and sand support member inside the first hole, and using a casing for the pre-struck steel pipe sheet pile driving scheduled part adjacent to the post-struck steel pipe sheet pile driving planned part. A step (c) of forming a second hole in the ground so that the end of the first hole overlaps with the first hole, and a pre-tipped steel pipe sheet pile is installed in a casing inside the second hole, A step (d) of filling the gap between the casing and the inside of the steel pipe sheet pile with the first mortar, and pulling out the casing from the second hole; and the earth and sand supporting member inside the first hole. On the other hand, a step (e) of placing a post-rolled steel pipe sheet pile, The earth and sand support member is a structure defined by a plurality of partitions communicating in a vertical direction, and a lid is formed above the structure, and after the step (e), the structure Is filled with a second mortar, and is a construction method of a steel pipe sheet pile. In this case, the partition of the structure is provided with a plurality of through holes penetrating in the horizontal direction, and the first mortar includes aggregates for pre-tipped steel pipe sheet piles, It is desirable that the size is larger than the flow hole.

The ground of the post-cast steel pipe sheet pile placement planned portion and / or the pre-cast steel pipe sheet pile placement planned portion is a ground in which a soft ground is formed on the rock, and the step (a) includes the rock and the soft ground It is desirable that the earth and sand support member is provided up to the vicinity of the boundary with the ground.

In the step (d), before filling the first mortar, a rod-shaped member is inserted into the first joint formed along the longitudinal direction on the side surface of the pre-tipped steel pipe sheet pile, The penetration of the first mortar into the inside of the joint is suppressed, and the rod-shaped member is removed before the step (e), and the step (e) is performed in the longitudinal direction on the side surface of the post-worked steel pipe sheet pile. It is desirable to place the post-work steel pipe sheet pile so that the second joint formed along the first joint and the first joint are fitted.

According to the first and second inventions, the first hole is provided with the earth and sand support member while the casing is pulled out, and the second hole adjacent to the first hole is provided with the mortar after the pre-installed steel pipe sheet pile is installed in the casing. Since the casing is extracted by filling the adjacent steel pipe sheet piles, the adjacent casing sheet piles can be efficiently placed without interfering with each other. In addition, since the post-cast steel pipe sheet pile is placed on the earth and sand support member, earth and sand do not flow into the post-placed steel pipe sheet pile placement site. Since the casing for the steel pipe sheet pile is installed (perforated) so as to remove a part of the sediment support member, the steel pipe sheet piles can be joined to each other.

  In addition, if the earth and sand support member is provided up to the vicinity of the boundary between the rock and the soft ground, the inflow of earth and sand (the inflow of earth and sand into the hole on the rock side) can be prevented more reliably.

  In addition, by inserting a rod-like member into the joint on the side of the steel pipe sheet pile before filling the mortar into the steel pipe sheet pile, it prevents the mortar from flowing into the joint and prevents the joint from being blocked. Can do. For this reason, a mutual joint can be made to fit at the time of placement of a post-rolled steel pipe sheet pile.

In addition, if the sediment support member is a super setting delay type mortar, the hardening of the super setting delay type mortar has progressed even after filling the steel plate sheet pile installation part with the sediment support member and installing the precast steel pipe sheet pile. It is easy to install a post-rolled steel sheet pile. Moreover, after the installation, the hardening of the super-set delay type mortar proceeds, and the steel pipe sheet pile can be fixed with high strength. At this time, if the setting delay of the super setting delay type mortar is at least twice as long as the construction time of the pre-cast steel pipe sheet pile (the construction period for both sides of the post-cast steel pipe sheet pile), it is super condensed even after installation of the pre-made steel pipe sheet pile. The effect of the delayed mortar does not proceed, and it is easy to place a post-rolled steel sheet pile. Moreover, if the final compressive strength of a super setting delay type mortar is 10 N / mm < ² > or more, a steel pipe sheet pile can be reliably fixed to the ground.

  Super-aggregation-type mortar can increase strength if aggregates for post-pipe steel sheet piles are added, and if thickeners are added, the aggregate is lowered by holding for a long time. It is possible to suppress sedimentation.

  In addition, as a sediment support member, a structure having a plurality of holes (plural partitions) communicating in the vertical direction is used, and by forming a lid on the top, inflow of sediment from above can be prevented, and If the post-fired steel pipe sheet pile is driven against the structure, the post-fired steel pipe sheet pile can be reliably driven. At this time, if the structure is filled with mortar, the post-cast steel sheet pile can be reliably fixed to the ground.

  Further, if a plurality of through holes penetrating in the horizontal direction are formed in the partition of the structure, the mortar can pass through the through holes at the time of mortar filling, so that the structure can be more reliably filled. At this time, if the steel sheet pile sheet aggregate is included in the mortar used at the time of casting the steel pipe sheet pile, and the aggregate for the steel sheet pile sheet is larger than the flow hole, the steel pipe at the time of casting the steel pipe sheet pile is provided. It can suppress that the aggregate for sheet piles is plugged into the flow hole, and the mortar enters the inside of the structure. In addition, when using the aggregate for post-coating steel pipe sheet piles, the aggregate for post-coating steel pipe sheet piles is smaller than the flow hole.

3rd invention is the structure constructed | assembled by the construction method of the steel pipe sheet pile concerning 1st and 2nd invention, Comprising: By the said post-coating steel pipe sheet pile provided in the said earth-and-sand support member, and the said 1st mortar The structure is characterized in that the fixed steel pipe sheet piles to be fixed are alternately formed.

According to the third aspect of the invention, it is possible to obtain a structure in which steel pipe sheet piles are reliably fixed to the ground, and adjacent steel pipe sheet piles are reliably joined even in a place where sedimentary earth or the like is present on the rock.

  According to the present invention, even when soft ground is present on the rock, a steel pipe sheet pile can be placed and fixed to the ground, and a steel pipe sheet pile construction method having excellent workability and a structure using the same Can be provided.

It is a figure which shows the structure 1, (a) is an elevation view, (b) is a top view. The figure which shows the construction method of a steel pipe sheet pile, and is a figure which shows the process of penetrating a casing. The figure which shows the construction method of a steel pipe sheet pile, and is a figure which shows the process of filling a super setting delay type mortar, removing a casing. It is a figure which shows the construction method of a steel pipe sheet pile, and is a figure which shows the state which filling of the super setting delay type mortar was completed. It is a figure which shows the construction method of a steel pipe sheet pile, and is a figure which shows the process of penetrating a casing in the site | part which adjoins further, (a) is an elevation view, (b) is the BB sectional drawing of (a). It is a figure which shows the construction method of a steel pipe sheet pile, and is a figure which shows the process of installing a steel pipe sheet pile in a casing, (a) is an elevation view, (b) is CC sectional view taken on the line of (a). It is a figure which shows the construction method of a steel pipe sheet pile, and is a figure which shows the process of filling mortar, removing a casing, (a) is an elevation view, (b) is CC sectional view taken on the line of (a). It is a figure which shows the construction method of a steel pipe sheet pile, and is a figure which shows the process of placing a steel pipe sheet pile in a super setting delay type mortar, (a) is an elevation view, (b) is a CC line sectional view of (a). . The figure which shows the state which the placement of the steel pipe sheet pile was completed. It is a top view of a structure, and is a figure showing the placing order of a steel pipe sheet pile. It is a figure which shows the state which replaced with the super setting delay type mortar, and has shown the state which installed the structure 25, (a) is an elevation view, (b) is the GG sectional view taken on the line (a), (c) is (a). HH sectional view taken on the line. The figure which shows the process of placing a steel pipe sheet pile in the structure. KK sectional drawing of FIG.12 (b).

  Hereinafter, the construction method and the like of the steel pipe sheet pile according to the embodiment of the present invention will be described. 1A and 1B are diagrams showing a structure 1 according to the present invention, in which FIG. 1A is an elevation view of the structure 1 and FIG. 1B is a plan view of the structure 1. The structure 1 is mainly formed of a steel pipe sheet pile 5, a bottom plate 9, an uplift 7 and the like.

  The ground 3 is excavated, and a plurality of steel pipe sheet piles 5 are arranged in a circle. The ground 3 has a bedrock 3b below, and a soft ground 3a such as sedimentary soil is formed above the bedrock 3b. The steel pipe sheet pile 5 is provided to the depth of the bedrock 3b. A bottom plate 9 is provided at the bottom of the structure 1 surrounded by the steel pipe sheet pile 5. In addition, on the inner surface of the steel pipe sheet piles 5 arranged in a circle, a bulge 7 as a reinforcing member is installed in a circle. In addition, although mentioned later for details, the steel pipe sheet piles 5 are joined by a coupling. Further, the arrangement of the steel pipe sheet piles is not limited to a circle, and can be applied to various shapes such as a rectangle.

  Next, the construction method of the structure 1 will be described. FIG. 2 is an elevation view showing a state in which the casing 11a is installed. First, the hole 13a is excavated using the casing 11a by an all-around rotary excavator so that the ground 3 reaches the rock 3b. The earth and sand inside the casing 11a is discharged. Therefore, the lower end of the casing 11a reaches the bedrock 3b, and the upper end of the casing 11a reaches above the soft ground 3a.

  Next, as shown in FIG. 3, the casing 11a is pulled out from the hole 13a (in the direction of arrow A in the figure), and the inside of the casing 11a (inside the hole 13a) is filled with the supercondensation delay type mortar 15 as a sediment support member. The super setting delay mortar 15 is filled up to the vicinity of the boundary between the rock 3b and the soft ground 3a. That is, the super setting delay mortar 15 is filled in a part below the rock 3b and the soft ground 3a. The soft ground 3a portion is backfilled with excavated soil inside the casing or sand to be added separately. The super-set delay mortar 15 may be filled up to the vicinity of the boundary between the rock 3b and the soft ground 3a, or may be slightly lower than the boundary.

  In addition, as the super setting delay mortar 15, gluconic acid, glucoheptonic acid, oxycarboxylic acid, or the like is used as a setting delay material. For example, gluconic acid may be added to the mortar by about 0.3 to 1.5%. If 0.3% of gluconic acid is added, a setting delay of about 200 hours can be obtained. In addition, setting delay property refers to time until the setting starts after the production | generation of mortar.

  The filling portion (excavation position of the hole 13a) of the super setting delay mortar 15 as described above is formed in a post-punched steel pipe sheet pile placing scheduled portion. That is, although mentioned later for details, it becomes a site | part in which a post-worked steel pipe sheet pile is driven. The same process is repeated, and as shown in FIG. 4, the supercondensation delay mortar 15 is filled in a portion where the post-pipe steel pipe sheet piles are to be placed at a predetermined interval (scheduled steel pipe sheet pile placement portion). In addition, as for the space | interval of the post-punched steel pipe sheet pile driving | running | working plan parts, the distance which can be set in the steel pipe sheet pile mentioned later is opened. That is, the portion between the post-striking steel pipe sheet pile placement scheduled portions becomes the pre-struck steel pipe sheet pile placement planned portion. In the following drawings, only the central super setting delay mortar 15 is shown, and the portions formed on both sides at intervals are not shown.

  FIG. 5 is a view showing a state in which the casing 11b is installed, FIG. 5 (a) is an elevation view, and FIG. 5 (b) is a cross-sectional view taken along the line BB of FIG. 5 (a). As shown in FIG. 5 (a), a hole 13b is formed in the ground 3 of the previously-mentioned steel pipe sheet pile placing portion (next to the steel plate sheet pile placing planned portion) using a casing 11b by an all-around rotary excavator. Drilling. The lower end of the casing 11 b also reaches the bedrock 3 b and the upper end is exposed on the ground 3. At this time, as shown in FIG. 5B, the hole 13b is formed so that a part of the hole 13a and a part of the hole 13b overlap each other. In addition, the earth and sand, mortar, etc. in the casing 11b are discharged | emitted.

  6A and 6B are views showing a state in which the steel pipe sheet pile 5a is installed in the casing 11b. FIG. 6A is an elevation view, and FIG. 6B is a cross-sectional view taken along the line C-C in FIG. As shown in FIG. 6, a steel pipe sheet pile 5a which is a pre-tipped steel pipe sheet pile is inserted into the casing 11b. As shown in FIG. 6B, the steel pipe sheet pile 5a is provided with joints 19a at both ends. A pair of the joints 19a is provided at positions facing the outer surface of the steel pipe sheet pile along the longitudinal direction of the steel pipe sheet pile 5a. The joint 19a is a member having a C-shaped cross section that is partially opened.

  Next, as shown in FIG. 7, while filling the gap between the casing 11b and the steel pipe sheet pile 5a and the inside of the steel pipe sheet pile 5a with the mortar 21 as the first mortar, the casing 11b is pulled out before the mortar 21 is solidified (in the drawing). Arrow D direction). Therefore, the mortar 21 is filled in the gap between the steel pipe sheet pile 5a and the hole 13b (rock 3b) and the inside of the steel pipe sheet pile 5a. When the mortar 21 is filled, the rod-like member 23 is inserted into the joint 19a in advance. Therefore, the mortar 21 is not filled in the joint 19a. For example, the mortar 21 may be filled to a height that is approximately the same as the filling height of the super setting delay mortar 15. The steel pipe sheet pile 5a is installed by the above.

  The rod-shaped member 23 may have not only a circular cross section but also a convex portion that does not fill the slit portion of the joint 19a, and the mortar so that a joint 19b described later can be fitted to the joint 19a. What is necessary is just to use the thing of the cross-sectional shape which can form this non-filling part. Moreover, it is desirable to provide a mortar peeling member on the outer periphery of the rod-shaped member 23.

  Next, as shown to Fig.8 (a), after the mortar 21 solidifies, the steel pipe sheet pile 5b which is a post-coating steel pipe sheet pile is inserted in the super condensing delay mortar 15 (arrow E direction in the figure). In inserting the steel pipe sheet pile 5b, the rod-shaped member in the joint 19a is removed in advance, and the joint 19b of the steel pipe sheet pile 5b and the joint 19a of the steel pipe sheet pile 5a are fitted as shown in FIG. 8 (b). insert. In addition, in the soft ground 3a, when the steel pipe sheet pile 5b is inserted, the excavated soil or sand buried in the insertion site can easily escape to the surroundings, so that the steel pipe sheet pile 5b can be easily inserted. In the rock mass 3b, the steel pipe sheet pile 5b can be easily inserted because it is before the setting of the super setting delay mortar 15 and still has fluidity.

In addition, as the setting delay property of the super setting delay mortar 15, as described above, after setting the steel pipe sheet pile 5a at least on both sides, it does not have to be set until the steel pipe sheet pile 5b is set. For this reason, it should just have the setting delay property more than twice the placing man-hour of the steel pipe sheet pile 5a (period until two steel pipe sheet piles 5a are driven). For example, when the number of days for placing the steel pipe sheet pile 5a is about 4 days, it is sufficient that the setting delay is 8 days or more (about 200 hours). Further, in order to securely fix the steel pipe sheet pile 5b, at least the final compressive strength needs to be 10 N / mm ² or more. For example, with the addition of 0.3% gluconic acid, a maximum of about 50 N / mm ² is possible. In addition, what is necessary is just to adjust a setting retarding property (addition amount of a setting retarder) suitably according to the placement order, process, etc. of a steel pipe sheet pile.

  FIG. 9 is a diagram showing a state in which the steel pipe sheet piles 5a and 5b are installed by the above process. The super setting delay mortar 15 sets and solidifies after a predetermined setting delay, whereby the steel pipe sheet pile 5b is also fixed to the rock mass 3b. Thus, the steel pipe sheet piles 5a and 5b are driven.

  Next, the placing order of each steel pipe sheet pile will be described. FIG. 10 is a view showing a state where the steel pipe sheet piles 5a and 5b are driven. As described above, the steel pipe sheet pile 5a, which is a pre-struck steel pipe sheet pile, is placed on the steel pipe sheet pile placement part 24a, which is a pre-struck steel pipe sheet pile placement part, and the steel pipe sheet pile 5b, which is a post-punch steel pipe sheet pile, is post-struck. The steel pipe sheet pile placement portion 24b, which is a steel pipe sheet pile placement portion, is driven. The steel pipe sheet pile placing scheduled portion 24a and the steel pipe sheet pile placing scheduled portion 24b are alternately set. Placing the steel pipe sheet piles may be performed, for example, in groups of several adjacent ones. For example, after construction for group I in FIG. 10, construction may be performed in the order of group II, group III,..., Group IX. In any case, the steel pipe sheet pile 5a and the steel pipe sheet pile 5b may be formed alternately.

  For example, the steel pipe sheet pile placing portion 24b at the T position is filled with the super setting delay mortar 15 (first step), and the steel pipe sheet pile placing planned portion 24a at the S position sandwiched between the super setting delay mortar 15 filling portions 24a. After the steel pipe sheet pile 5a is placed (second step), the steel pipe sheet pile placing planned portion 24b at the V position is filled with the supercondensation delay mortar 15 (third step), and the steel pipe sheet pile placing planned portion 24a at the U position is filled. The steel pipe sheet pile 5a is driven (fourth step). Next, the steel pipe sheet pile 5b is placed at the T position, which is a filling portion of the supercondensation delay mortar 15 sandwiched between the steel pipe sheet piles 5a (fifth step). As described above, it may be constructed in the circumferential direction one by one.

  In any case, the steel pipe sheet pile 5a is formed at a position sandwiched between the supercondensation delay mortar filling portions of the planned placement position of the steel pipe sheet pile 5b formed at a predetermined interval. What is necessary is just to install the steel pipe sheet pile 5b in the super congealing delay mortar filling part of the position pinched | interposed between them. By repeating the above, the steel pipe sheet pile 5b fixed by the super setting delay mortar and the steel pipe sheet pile 5a fixed by the mortar 21 are alternately formed.

  According to the construction method of the steel pipe sheet pile according to the present embodiment, it is possible to reliably install the steel pipe sheet pile even at the site where the soft ground 3a is formed on the rock 3b in the lower part. In particular, a sediment support member is used, and there is no blockage of the hole due to collapse of the backfilled excavated soil or sand into the hole in the rock. For this reason, the insertion work of the steel pipe sheet pile in a rock part and the fixation of a steel pipe sheet pile can be performed reliably. In soft ground, since earth and sand can easily flow around, there is no problem in inserting a steel pipe sheet pile even if the hole is filled.

  Moreover, since the earth and sand support member is a super-aggregation delay mortar, it can support earth and sand from above and prevent inflow of earth and sand into the hole in the rock, and the setting is delayed when the steel pipe sheet pile 5b is placed. Therefore, it is easy to insert the steel pipe sheet pile 5b, and thereafter, the steel pipe sheet pile 5b is securely fixed because it is condensed at a predetermined strength or more. That is, since the setting delay mortar does not start during the placement of the two adjacent steel pipe sheet piles 5a, the super setting delay mortar does not set when the steel pipe sheet pile 5b is placed. In order to express sufficient strength for fixing the sheet pile 5b, the steel pipe sheet pile is securely fixed.

  In addition, you may add an aggregate to a super setting delay mortar. In this case, it is desirable to add a thickener so that the aggregate does not settle to the lower part while being held for a long time. As the thickener, for example, a complex of an aromatic compound having a sulfone group and / or a salt thereof and an alkyltrimethylammonium salt, a cellulosic polymer, a clay mineral such as bentonite or sepiolite can be used.

  Next, the construction method of the steel pipe sheet pile according to the second embodiment will be described. In the present embodiment, the same components as those in FIGS. 2 to 9 are denoted by the same reference numerals, and redundant description is omitted. The second embodiment is substantially the same as the first embodiment, but differs in that a structure 25 is used in place of the super-aggregation delay mortar as the earth and sand support member.

  FIG. 11A is a diagram showing a process using the structure 25 and corresponds to FIG. 3. FIG. 11B is a cross-sectional view taken along the line GG of FIG. ) Is a cross-sectional view taken along line HH in FIG. As shown in FIG. 11B, the structure 25 is a cylindrical member having a honeycomb cross-sectional structure inside. That is, the structure 25 is a member that is partitioned by a plurality of partitions 27 provided in the longitudinal direction and that communicates with a plurality of holes 29. The outer diameter of the structure 25 is slightly smaller than the inner diameter of the casing 11a. The hole of the outer surface of the structure 25 should just be larger than the aggregate for post-coating steel pipe sheet piles, and should be smaller than the aggregate for pre-coating steel pipe sheet piles. Further, the shape of the hole 29 in the structure 25 may not be hexagonal, and may be any shape such as a square or a round shape. The structure 25 is a member made of ceramics or mortar.

  The partition 27 of the structure 25 is formed with a plurality of flow holes 31 that allow the holes 29 adjacent in the horizontal direction to communicate with each other. Further, a plurality of lids 17 a are provided above the structure 25. The lid 17a may be made of rubber or resin, and is installed so as to close the hole 29 above the structure 25.

  The structure 25 is inserted into the casing 11a and inserted into the hole 13a when the casing 11a is extracted (in the direction of arrow F in the figure). The structure 25 is provided up to the vicinity of the boundary between the rock 3b and the soft ground 3a. Further, the lid 17a installed at the lowermost side is installed so as to be the same as or slightly below the boundary portion.

  Then, the steel pipe sheet pile 5a is driven on both sides in the same procedure as FIGS. At this time, a part of the structure 25 is cut off when the hole 13b is excavated. Moreover, the aggregate for a steel pipe sheet pile is added to the mortar 21 used for fixing the steel pipe sheet pile 5b. The size of the aggregate for the steel pipe sheet pile is larger than the diameter of the flow hole 31 of the structure 25. Therefore, the mortar 21 does not flow into the structure 25.

  After the adjacent steel pipe sheet piles 5a are fixed, the steel pipe sheet piles 5b are arranged on the structure 25 as shown in FIG. 12 (a), and the steel pipe sheet piles 5b are driven (in the direction of arrow J in the figure). The steel pipe sheet pile 5b can be easily inserted in the soft ground 3b because the excavated soil, sand, etc. that have been backfilled can easily move around. In the bedrock 3b, the tip of the steel pipe sheet pile 5b is inserted while breaking the partition 27 of the structure 25. The lid 17a is similarly cut or broken at the tip of the steel pipe sheet pile 5b.

  As shown in FIG. 12 (b), when the steel pipe sheet pile 5b is completely inserted, the structure 25 (inside and outer peripheral portion of the steel pipe sheet pile 5b) is filled with the mortar 22 as the second mortar.

  FIG. 13 is a cross-sectional view taken along the line KK of FIG. As shown in FIG. 13, the mortar 22 passes through the flow holes 31 of the structure 25 and is filled in all the holes 29. That is, the steel pipe sheet pile 5 b is fixed by the mortar 22. Although many parts of the structure 25 are damaged as the steel pipe sheet pile 5b is placed, these pieces are solidified integrally with the mortar 22, and the steel pipe sheet pile 5b is securely fixed. Note that when the mortar 22 includes aggregate for post-cast steel pipe sheet pile, the size of the aggregate for post-pipe steel pipe sheet pile may be made smaller than the flow hole 31.

  According to the second embodiment, an effect similar to that of the first embodiment can be obtained. In addition, since the super setting delay mortar is not used, the setting time of the super setting delay mortar is not a concern. For this reason, it is not necessary to control or manage the amount of setting retarder added based on temperature, process, and the like.

  Further, since the structure 25 is formed with the lid 17a on the upper side, it can reliably support the earth and sand from above, and can prevent the earth and sand from flowing into the structure 25b (inside the hole 13a in the rock). . In particular, since a plurality of lids 17a are formed, the earth and sand can be supported more reliably.

  The structure 25 is made of ceramics or mortar, and can be easily broken by the steel pipe sheet pile 5b. For this reason, at the time of placing the steel pipe sheet pile 5b, the lid 17a and the partition 27 of the structure 25 are broken by the tip of the steel pipe sheet pile 5b, and the steel pipe sheet pile 5b is inserted into the structure 25. For this reason, when the steel pipe sheet pile 5b is placed, there is no adverse effect due to earth and sand. In addition, since many spaces (holes 29) are formed in the structure 25, broken pieces and the like are pushed away into these spaces. Therefore, it is easy to place the steel pipe sheet pile 5b.

  Since the flow hole 31 is provided in the partition 27 of the structure 25, the entire structure 25 is filled with the mortar 22 after the steel pipe sheet pile 5 b is placed. Therefore, the steel pipe sheet pile 5 can be reliably fixed.

  Further, the size of the flow hole is smaller than the aggregate for the pre-tipped steel pipe sheet pile added to the mortar 21 used for installing and fixing the adjacent steel pipe sheet pile 5a. Therefore, even if the mortar 21 is filled in a state in which a part of the structure 25 is cut off, the aggregate for the steel pipe sheet pile is clogged in the flow hole 31, so that the mortar 21 flows into the structure 25 and fills the space. It will never be buried. In addition, the size of the flow hole is larger than that of the aggregate for the post-rolled steel pipe sheet pile included in the mortar 22. Therefore, the mortar 22 does not clog the flow hole.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

1 ... Structure 3 ... Ground 3a ... Soft ground 3b ... Rocks 5, 5a, 5b ... Steel pipe sheet pile 7 ... Raised 9 ... Bottom plates 11a, 11b ... Casing 13a, 13b ......... Hole 15 ......... Super setting delay type mortar 17, 17a ......... Cover 19a, 19b ......... Joint 21 ......... Mortar 23 ......... Bar-shaped member 24a, 24b ......... Steel sheet pile Planned portion 25 ......... Structure 27 ......... Partition 29 ......... Hole 31 ......... Flow hole

Claims (8)

A steel pipe sheet pile construction method,
A step (a) of forming a first hole in the ground using a casing in a post-punched steel pipe sheet pile placing scheduled portion;
A step (b) of pulling out the casing from the first hole and providing an earth and sand support member inside the first hole;
Step (c) of forming a second hole in the ground so that the first hole and the end overlap with each other by using a casing in the pre-struck steel pipe sheet pile driving scheduled part adjacent to the post-struck steel pipe sheet pile driving planned part. When,
A steel pipe sheet pile is installed in the casing inside the second hole, the gap between the steel pipe sheet pile and the casing and the inside of the steel pipe sheet pile is filled with the first mortar, A step (d) of pulling out the casing from the hole;
A step (e) of placing a post-rolled steel pipe sheet pile against the earth and sand support member inside the first hole;
Equipped with,
The earth and sand support member is a super setting delay type mortar having a setting delay property,
Gluconic acid is added in an amount of 0.3 to 1.5% as the setting retarder in the super set retarding mortar. During the steps (c) and (d), the setting of the super set retarding mortar is performed. The construction method of the steel pipe sheet pile characterized by not starting . The ultra-setting delay type mortar has a setting delay property that is twice or more the number of days required for the step (c) and the step (d), and has a final compressive strength of 10 N / mm ² or more. The construction method of the steel pipe sheet pile according to claim 1 . The construction method of a steel pipe sheet pile according to claim 1 or 2 , wherein an aggregate for a post-coating steel pipe sheet pile and a thickener are added to the super setting delay type mortar. A steel pipe sheet pile construction method,
A step (a) of forming a first hole in the ground using a casing in a post-punched steel pipe sheet pile placing scheduled portion;
A step (b) of pulling out the casing from the first hole and providing an earth and sand support member inside the first hole;
Step (c) of forming a second hole in the ground so that the first hole and the end overlap with each other by using a casing in the pre-struck steel pipe sheet pile driving scheduled part adjacent to the post-struck steel pipe sheet pile driving planned part. When,
A steel pipe sheet pile is installed in the casing inside the second hole, the gap between the steel pipe sheet pile and the casing and the inside of the steel pipe sheet pile is filled with the first mortar, A step (d) of pulling out the casing from the hole;
A step (e) of placing a post-rolled steel pipe sheet pile against the earth and sand support member inside the first hole;
Equipped with,
The earth and sand support member is a structure that is partitioned by a plurality of partitions that communicate in the vertical direction, and a lid is formed above the structure, and after the step (e), inside the structure The construction method of the steel pipe sheet pile characterized by filling a 2nd mortar . The partition of the structure is provided with a plurality of flow holes penetrating in the horizontal direction, and the first mortar includes aggregate for a steel pipe sheet pile, and the size of the aggregate for the steel pipe sheet pile is The construction method of the steel pipe sheet pile according to claim 4 , wherein the construction is larger than the flow hole. The ground of the post-cast steel pipe sheet pile placement planned portion and / or the pre-cast steel pipe sheet pile placement planned portion is a ground in which a soft ground is formed on the rock.
The construction method for a steel pipe sheet pile according to any one of claims 1 to 5, wherein in the step (a), the earth and sand support member is provided up to the vicinity of a boundary between the rock and the soft ground. In the step (d), before filling the first mortar, a rod-shaped member is inserted into a first joint formed along the longitudinal direction on the side surface of the pre-tipped steel pipe sheet pile, Suppress the penetration of the first mortar into the interior,
Before the step (e), the rod-shaped member is removed,
In the step (e), the post-worked steel pipe sheet pile is driven so that the second joint formed along the longitudinal direction on the side surface of the post-work steel pipe sheet pile and the first joint are fitted. The construction method of the steel pipe sheet pile according to any one of claims 1 to 6 . A structure that is applied by the construction method of a steel pipe sheet pile as claimed in any one of claims 7, is fixed and the latter of steel sheet pile provided in the soil supporting member, by the first mortar The structure is characterized in that the pre-tipped steel pipe sheet piles are alternately formed.

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