JPH11229364A - Forming method for subsoil exploration hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming an exploration hole for measuring changes in the quality of subsoil below the underground part of an existing structure, such as the basement of a building, and the movement of the subsoil, in repairing or reconstructing the exterior wall or inside of the structure. SOLUTION: During the repair or reconstruction of an existing structure B whose underground part B1 is constructed at or below the underground water level W of subsoil E, a guide casing (K) is vertically placed on the bottom pressure-resisting base (F) of the underground part B1 and secured thereto, and after water is poured into the casing to fill the casing with water up to approximately the same height (h) as the underground water level W of the peripheral subsoil, a boring rod is inserted and lowered into the casing K. Thereafter, the boring rod is driven and rotated to bore a hole through the pressure resisting base (F), and the subsoil E below the pressure resisting base (F) is drilled to form a vertical exploration hole H for measuring the movement of the subsoil and changes in the quality of the subsoil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention measures changes and movements of ground properties on the ground below an underground part when renovating or renovating the outer wall or the interior of an existing structure having an underground part such as a basement of a building. The present invention relates to a forming method for forming an inspection hole for performing an inspection.

[0002]

2. Description of the Related Art FIG. 1 shows an existing structure B such as a building.
It is constructed below. When such a structure is repaired or renovated, the weight of the structure B itself changes due to the removal of internal pillars, walls, and floor slabs, or the extension, and therefore, the ground E that supports the structure during the renovation loosens (rebound). As a result, the properties of the ground change due to sinking, and as a result, there is a risk that the structure may be tilted or cracks may occur in the walls and floors.

[0003]

The existing structure B
At the time of renovation and renovation, an investigation hole is drilled in the lower ground supporting the structure, and a subsidence gauge is buried in the hole to measure the change in the ground. In the structure having the hole, the above-described drilling work is a work in a narrow space inside the basement room, and has a disadvantage that a great deal of labor and time are required.

[0004] In particular, in a structure where the underground portion is constructed below the groundwater level of the surrounding ground, when drilling work by hollowing out the pressure-resistant panel at the bottom of the structure, the pressurized groundwater is discharged from the bored hole. Not only is it not possible to perform sufficient drilling work due to outflow (spout), but also it is not possible to form an investigation hole itself. Even if an investigation hole can be formed, measurement such as a subsidence meter in the investigation hole The above-mentioned outflow became a problem during the insertion and installation of the equipment, and the groundwater flowed out during the measurement after the installation, and the properties of the ground changed, so that there was a drawback that accurate measurement was not possible.

[0004]

In order to solve the above-mentioned problems, in the method for forming an investigation hole in the ground according to the present invention, an existing structure in which an underground portion of the structure is constructed below the groundwater level of the ground is repaired or renovated. At this time, the guide casing is vertically mounted and fixed on the bottom pressure plate of the underground part, and the inside of the casing is filled with water to fill substantially the same level as the groundwater level of the surrounding ground, and then the boring rod is inserted into the casing. Then, the boring rod is driven to rotate, and the pressure plate is drilled and penetrated, and the ground below the pressure plate is drilled to measure ground movement and changes in properties. It is characterized by forming a hole.

[0005] The guide casing may be erected by connecting a plurality of short casings of several meters or less in sequence.

Further, a stratified subsidence measurement device in which one or more subsidence meters are vertically connected is inserted into a guide casing in which water is filled to a level substantially equal to the groundwater level of the surrounding ground. It may be settled in the investigation hole formed below, and may be buried so that each sunkometer is at a predetermined position in the depth direction.

In addition, a pore water pressure measuring device in which one or a plurality of pore water pressure gauges are vertically connected is inserted into a guide casing in which water is filled to the same level as the groundwater level of the surrounding ground. It may be settled in an investigation hole formed below and buried so that each pore water pressure gauge is at a predetermined position in the depth direction.

[0008]

According to the above-described method for forming a survey hole in the ground, the ground is drilled after the inside of the guide casing erected on the pressure plate is filled with water to substantially the same level as the groundwater level of the surrounding ground. The water pressure in the guide casing and the pressure of the pressurized groundwater are balanced and there is no outflow of the pressurized groundwater.
Even if the underground part is a structure constructed below the groundwater level of the surrounding ground, an investigation hole can be easily formed in the ground below the structure, and the risk of loosening and collapse of the hole wall ground by preventing runoff And a highly accurate inspection hole can be formed.

In the case where a plurality of short casings each having a length of several meters or less are successively connected to each other to erect a guide casing, the erecting operation of the casing is easily performed even in a narrow working space such as an underground room. And a guide casing of a predetermined length can be erected.

[0010] Furthermore, a stratified subsidence measuring device is inserted into a guide casing in which water is filled up to substantially the same level as a groundwater level, and is settled and buried in an investigation hole.
During burial work, there is no outflow of pressurized groundwater and no flow of groundwater in the survey hole, and it is easy to insert stratified subsidence measurement devices into the survey hole and bury the work, and set each submergence meter in the depth direction. It can be reliably buried in a predetermined position.

In the case where a pore water pressure measuring device is settled and buried in a survey hole in a guide casing in which water is filled to substantially the same level as the groundwater level, the outflow of the pressurized groundwater during the burying operation is reduced. There is no upward flow of groundwater in the investigation hole, the insertion of the pore water pressure measuring device into the investigation hole and the burying work can be performed reliably, and each pore water pressure gauge can be accurately embedded at a predetermined position in the depth direction.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 and FIG. 2 show an existing structure B such as a building to be renovated or renovated on the outer wall or the inside of the building,
An underground portion B1 such as an underground room is constructed in the ground below the groundwater level W of the ground E. According to the present invention, when the existing structure B having the underground portion B1 below the groundwater level is repaired or reconstructed, the change and movement of the properties of the ground are measured on the ground below (directly below) the underground portion supporting the structure. This is to be described below, and is described below.

In FIG. 3 and FIG. 4, K denotes a guide casing which is used in the forming method of the present invention by being erected on a pressure platen F which is a floor slab of a bottom portion of the underground portion B1 of the structure. In order to be suitable for work in space, cylindrical casings k1, k2,... Kn formed in a short length of several meters or less are connected so as to have a predetermined length.

In the figures, reference numerals 1 and 2 denote short casings k2 and k3.
.. Male and female screws for connecting Kn upward and downward, provided on the lower peripheral surface and the upper inner peripheral surface of short casings k2, k3. The short casings are connected so that the screw 1 and the female screw 2 are engaged with each other and screwed together.

At the lower end of the short casing k1, which is the lowermost step when the guide casing K is erected and used, a connecting flange 3 for fixing to a pressure-resistant panel F of an underground portion B1 such as a basement is provided. A female screw 2 similar to the above is formed on the inner periphery of the upper end of the casing.

In the figure, 4, 4 '... Are a plurality of bolt holes provided on the surface of the connecting flange 3, 5 is a drain hole provided through the upper side wall of the short casing k1, and 6 is the drain hole. 5 is a stopper plug which is screwed and sealed.

The method for forming a survey hole in the ground according to the present invention is carried out using the above-described guide casing K, which will be described in detail below.

FIGS. 1 and 2 show an existing structure B such as a building whose interior is to be renovated or renovated. The underground part (basement) B1 such as a basement is constructed below the groundwater level W of the ground E as described above. Have been. In repairing such a structure, according to the present invention, the ground E immediately below the existing structure B is used.
In order to measure the change and movement of the properties of the ground, an inspection hole H is formed. Prior to the drilling of the inspection hole H, first, on the pressure-resistant panel F immediately above the drilling (planned) position, Anchor bolts 7, 7 ',... For erecting and fixing (connecting) the short casing k1 are implanted and fixed.

In accordance with the above, the floor slabs f1, f2,...
In order to be able to erected, a portion corresponding to the erection is bored with a lifting machine or a concrete cutter to form an opening fa.

In this state, the lowermost short casing k1
Is suspended by a small crane or the like, and anchor bolts 7, 7 ′ are inserted into bolt holes 4, 4 ′,.
.. are inserted vertically to stand vertically on the pressure-resistant panel F, and nuts 8, 8 'are screwed into anchor bolts 7, 7'.
Is connected and fixed on the pressure-resistant panel F (Fig. 5
(A)). In this case, a packing 9 may be attached to the lower surface of the flange 3 and connected so that the casing k1 comes into close contact with the pressure-resistant panel F (FIG. 4).

Next, as shown in FIG. 5 (b), a casing k2 as a second stage is connected to the upper portion of the casing k1 by screws and extended upward. Similarly, the casing k3. When the guide casing K is continuously connected to the hole, the guide casing K having a predetermined length is erected vertically on the pressure-resistant panel F immediately above the drilling position (FIG. 5C).

Here, the predetermined length of the guide casing K means that when the guide casing K is erected on the pressure-resistant board F of the underground part (basement) B1, at least the top of the casing K is at the groundwater level W of the surrounding ground E. Higher than (higher position)
The ground condition and underground part (basement) B1
A certain number of short casings k1, k
2 ··· Kn are used in series.

As described above, when the erecting of the guide casing K is completed, water is injected into the erect casing K by a pump or the like, and as shown in FIG. Fill water up to approximately the same level (same height) as the groundwater level W. This is to prevent infiltration and outflow of groundwater into the casing K pipe due to pressurized water when drilling the inspection hole H described later. Since the casing water level h is equal to the groundwater level W, in other words, the guide Since the water pressure of the water filled in the casing is applied to the upper portion of the drilled hole, the water pressure of the pressurized groundwater is balanced, and there is no outflow of the pressurized groundwater from the hole.

In this state, the boring device R installed on the floor slab f5 or the like near the upper portion of the guide casing K is operated, and the boring rod 10 is pulled from the top of the casing K.
Is inserted into the casing and lowered.

The tip cutter 11 of the boring rod 10
When the pressure reaches the upper surface of the pressure plate F, the boring rod is rotationally driven to penetrate the hole (Fa) of the pressure plate F, and the boring rod 10 is further lowered to drill the ground E below the pressure plate F ( FIG. 5D).

When drilling to a predetermined depth is completed, the boring rod 10 is pulled up and collected from the inside of the guide casing K. A vertical investigation hole H for measurement is formed.

In the present invention, a stratified subsidence measuring device T, a pore water pressure measuring device S, and the like for measuring a change or movement of the properties of the ground are inserted and installed in the inspection hole H formed as described above. This will be described below.

As shown in the buried diagram of FIG. 9, the stratified subsidence measuring device T is a commonly used series multistage stratified subsidence meter.
Multiple sinkers 20a, 20b, such as differential transformer type
Are connected to the rod 21 at predetermined intervals at upper and lower stages, and an outer tube 22 such as a bellows hose for friction cutting is externally inserted into the rod 21.

Reference numeral 23 denotes each of the sinkers 20a, 2
0b... Are individually extended, and each cable is extended upward, and a plurality of measurement cables are bundled and fixed to the rod 21 near the upper end of the rod 21. The other end of the measuring cable 23 extended upward is connected to the sinking measuring device Gt after installing the stratified sinking measuring device T in the investigation hole H, and measures displacement such as sinking or lifting of the ground. It will be.

In the present invention, the stratified settlement measuring apparatus T having the above-described structure is used.
Is suspended by a wire rope 24 attached to the lower end of the sinking measuring device and inserted and buried in the inspection hole H formed as described above. In this case, in order to prevent outflow of the pressurized water, the casing K While the water is still filled, the stratified sedimentation measuring device T is inserted into the casing from the top of the casing K and lowered, and further settled to a predetermined depth in the investigation hole H, and the respective subsidence meters 20a, 20b Are buried so as to be located in a predetermined stratum of the ground to be measured (FIG. 6).
(A)).

In the figure, reference numeral 25 denotes a mortar injected into the hole bottom for fixing the stratified subsidence measuring device T after the stratified subsidence measuring device T is installed, and 26 denotes a space filled between the ground and the outer pipe 22. Grout.

The measurement cables 23 are bundled and passed through a hole Fa of the pressure-resistant panel F to form an upper guide casing K.
And is temporarily fastened to the top of the casing or the like.

Next, when the ready-mixed concrete 27 'is put into the casing from the top of the guide casing K, the put-in fresh concrete falls under the water in the casing and is deposited on the pressure-resistant board F near the hole Fa. (FIG. 6
(B)).

After that, when the deposited ready-mixed concrete hardens, the upper portion of the inspection hole H is, as shown in FIG.
7, the plugged state is established, and the outflow of the pressurized groundwater from the hole Fa is prevented.

In this state, the drainage hole 5 of the lowermost casing k1 is drilled to drain water from the guide casing K, and the casings k2 and k3 above the casing k1 are drained.
Is removed by removing the screw connection (FIG. 6 (c)),
Thereafter, if the other end of the measuring cable 23 is connected to the sinking measuring device Gt installed at another position such as on a floor slab (FIG. 6)
(D)), the stratified settlement measuring device T buried in the investigation hole H
Thus, it becomes possible to measure changes in properties such as rising and subsidence of the ground E below the pressure platen F. in this case,
As shown in FIG. 8, the upper space of the casing k1 may be filled with concrete 27a, and the upper lid 28 and the like may be welded to further secure the sealed state.

By sealing the short casing k1 above the inspection hole H with the concrete 27 as described above, not only the outflow of the pressurized groundwater is stopped and the measurement work inside the underground room becomes easy, but also the investigation is performed. There is no upward flow of groundwater in the hole H, and accurate measurement can be performed. Also, by leaving only the shortest lower casing k1 and removing the upper casings k2, k3,..., A large work space can be obtained, and even when measuring the displacement of the ground, the floor slab f
Needless to say, renovation of 1, f2 ... and the basement can be performed.

As described above, the stratified settlement measuring device T in the investigation hole H
The embedding method has been described, but when the pore water pressure measuring device S is buried in the investigation hole H, the same method is used.
0, a plurality of pore water pressure gauges 30a, 30b,... Are provided on the wire rope 32 at predetermined intervals in a vertically arranged multistage manner. To hang it, insert it into the casing from the top of the casing K, further sink it and bury it at a predetermined depth in the investigation hole H.

In this case, in order to prevent the pressurized water from flowing out, the insertion and embedding of the pore water pressure measuring device S in a state where the water is filled in the upright guide casing K is performed according to the stratification. It is the same as in the case of the settlement measurement device T. After embedding, ready-mixed concrete is poured into the casing to solidify the vicinity of the hole-facing point Fa, and then, leaving only the lowermost casing k1 in the sealed state, the upper part is removed. Casing k
2, k3 ... are removed and a plurality of pore water pressure gauges 30a,
The measurement cables 31 individually connected to 30b... Are connected to the water pressure measuring device Gs to measure the change in pore water pressure in the ground E in the same manner as in the case of the stratified settlement measuring device T.

In FIG. 10, reference numeral 33 denotes a permeation boulder charged and filled around the pore water pressure gauges 30a, 30b,... In the inspection hole H, and 34, individual pore water pressure gauges 30a, 30b.
... are bentonite pellets for sealing the water permeability between them.

As described above, the investigation hole H is formed in the ground below the existing structure B.
The method of forming the survey hole has been described. However, the formation of the survey hole H in the ground is not limited to one place, and the survey hole H is drilled in a plurality of places in the lower ground as necessary for the survey, and each of the holes is formed. May be buried in combination with a stratified subsidence measuring device T and a pore water pressure measuring device S, and furthermore, a stratified subsidence measuring device T and a pore water pressure measuring device S composed of a single subsidence meter or a pore water pressure gauge.
May be inserted and buried in the investigation hole H for measurement, or a sedimentometer and a pore water pressure gauge may be used by combining them vertically.

[0041]

As described above, the method for forming a survey hole in the ground according to the present invention can be used to repair or rebuild an existing structure having an underground portion of a structure below the groundwater level of the ground. After vertically fixing the guide casing on the pressure-resistant panel and pouring it into the casing to fill it with water to substantially the same level as the groundwater level of the surrounding ground, insert the boring rod into the casing and lower it. The boring rod is rotationally driven to drill and penetrate the pressure plate, and a hole is drilled in the ground below the pressure plate to form a vertical inspection hole for measuring the movement and property change of the ground. Because of this, the pressure of the water filled in the guide casing is applied to the hollows when drilling the pressure plate or drilling the ground below it, so that the water pressure and the pressure of the groundwater to be pressed are balanced. Therefore, even if there is no outflow of pressurized groundwater from the hole, even if the underground part is a structure constructed below the groundwater level of the surrounding ground, an investigation hole can be easily formed in the ground below the structure, and the outflow can be reduced. By preventing the hole wall ground, there is an advantage that there is no fear of loosening or collapse of the hole wall ground, and a highly accurate inspection hole can be formed.

According to the second aspect of the present invention, the guide casing is erected by connecting a plurality of short casings of several meters or less in sequence. Even in a narrow work space,
The erecting operation of the casing can be easily performed, and the erecting of the guide casing having a predetermined length can be performed.

Further, according to the third aspect of the present invention, one or a plurality of submergence gauges are vertically connected in a guide casing in which water is filled to a level substantially equal to the groundwater level of the surrounding ground. The sedimentation subsidence measuring device is inserted and settled in the investigation hole formed under the casing, and each submergence meter is buried so that it is at a predetermined position in the depth direction. The pressure of the groundwater is balanced with the pressure of the groundwater, and there is no outflow of the groundwater and no flow of groundwater in the survey hole. There is an effect that the squat gage can be reliably buried at a predetermined position in the depth direction.

Also, in the invention according to claim 4, one or a plurality of pore water pressure gauges are vertically connected in a guide casing in which water is filled to substantially the same level as the groundwater level of the surrounding ground. The pore water pressure measurement device was inserted and settled in the investigation hole formed below the casing, and each pore water pressure gauge was buried so that it was at a predetermined position in the depth direction. There is no outflow and no flow of groundwater in the investigation hole, and the insertion and installation work of the pore water pressure measurement device into the investigation hole can be performed reliably, and each pore water pressure gauge can be accurately buried at a predetermined position in the depth direction. There are advantages.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing a relationship between an existing structure having an underground part to be renovated, a surrounding ground, and an investigation hole to be formed by the present invention.

FIG. 2 is a cross-sectional plan view of the same.

FIG. 3 is a partially cutaway side view of a guide casing used in the method of forming an inspection hole according to the present invention.

FIG. 4 is a partially cutaway side view showing the configuration of the guide casing.

5 (a) to 5 (d) are explanatory diagrams sequentially showing a method of forming a survey hole according to the present invention.

6 (a) to 6 (d) are illustrations sequentially showing a method of burying a stratified settlement measuring device in a survey hole.

FIG. 7 is an explanatory longitudinal sectional view showing a method of sealing the upper part of the inspection hole.

FIG. 8 is a vertical cross-sectional view showing a sealed state above the inspection hole.

FIG. 9 is an explanatory longitudinal sectional view showing a state in which a stratified settlement measuring device is buried in an investigation hole.

FIG. 10 is an explanatory longitudinal sectional view showing a state in which a pore water pressure measuring device is buried in an inspection hole.

[Explanation of symbols]

 B Existing structure B1 Underground part (basement) F Pressure-resistant panel Fa Perforated area f1, f2 ... Floor slab K Guide casing k1, k2, Kn Short casing h Casing water level E Ground W Groundwater level H Survey hole R Boring Apparatus T Layer-by-layer subsidence measuring device Gt Subsidence measuring device S Pore water pressure measuring device Gs Water pressure measuring device 1 Male screw 2 Female screw 3 Connecting flange 4 Bolt hole 5 Drain hole 5 7, 7 'anchor bolt 10 Boring rod 20a, 20b ・ ・ ・ Sink gauge 21 Rod 23 Measurement cable 24 Wire rope 30a, 30b ・ ・ ・ Pore pressure gauge 31 Measurement cable 32 Wire rope

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Tameoka 2-1-2207 Minamitsukaguchi-cho, Amagasaki City, Hyogo Prefecture Inside of Keisoku Giken Co., Ltd. (72) Inventor Satoshi Sugimoto 2 Minamitsukaguchi-cho, Amagasaki City, Hyogo Prefecture (1-2) Inventor Kaoru Shimonagayoshi 2-1-2-1, Minamitsukaguchi-cho, Amagasaki-shi, Hyogo

Claims (4)

[Claims] When renovating or rebuilding an existing structure whose underground portion of the structure is below the groundwater level of the ground, a guide casing is vertically erected and fixed on the bottom pressure plate of the underground portion. After pouring water into the inside of the casing and filling it with water to substantially the same level as the underground water level of the surrounding ground, insert the boring rod into the casing and lower it, and then drive the boring rod to rotate and make the pressure-resistant panel perforate. In addition, a method for forming a survey hole in the ground, which comprises drilling a ground below the pressure plate to form a vertical survey hole for measuring a movement or a property change of the ground. 2. The method according to claim 1, wherein the erecting of the guide casing is performed by sequentially connecting a plurality of short casings of several meters or less. 3. A stratified subsidence measurement device in which one or more subsidence meters are vertically connected is inserted into a guide casing in which water is filled to a level substantially equal to the groundwater level of the surrounding ground. The method for forming a ground survey hole according to claim 1 or 2, wherein the sedimentation gauge is settled in a survey hole formed below, and each sunk gauge is buried at a predetermined position in a depth direction. 4. A pore water pressure measuring device in which one or a plurality of pore water pressure gauges are vertically connected is inserted into a guide casing in which water is filled to substantially the same level as the groundwater level of the surrounding ground. The sediment is settled in a survey hole formed below, and each pore water pressure gauge is buried so as to be at a predetermined position in the depth direction.
The method for forming a survey hole in the ground according to the above.