JP2011153505A - Slope frame fixing method for promoting ground anchor effect by setting expansion and contraction zone on slope frame bottom and adjusting sheath length - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an innovative slope frame fixing method which pressure-fixes a slope retaining member, such as a slope frame, to a ground slope by a ground anchor, so as to suppress disintegration of sliding soil. <P>SOLUTION: In the slope frame fixing method for anchoring the slope retaining member, such as the slope frame and a slope retainer, to the ground slope by the ground anchor, an expansion and contraction zone is set between the slope frame bottom and a grout head to separate them, thus obtaining an effect of fastening the soil. Further, the sheath length of the anchor is set higher than the sliding surface, so as obtain a detaining effect by an anchor body at the same time. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In order to enhance the effect of the ground anchor method, the present invention establishes a telescopic section on the bottom of the frame and adjusts the sliding sheath length of the ground anchor to promote the tightening and retaining effect of the sliding soil block. It relates to the construction method.

  The ground anchor method is generally divided into an anchor free length (sliding section of the lump) and an anchor body length (section in which the ground anchor is fixed to the base below the sliding surface). The tensile force T1 of the ground anchor 1 is determined by the tightening nut 2 Is fixed to the pressure bearing plate 3 and transmitted to the sliding section of the soil block of the free length L1 through the method frame 4 to generate a tightening effect, and has a cross-sectional structure that suppresses the slip of the soil block such as the soft ground. However, according to the investigations so far, the conventional ground anchor method has the head of the expanded diameter φ3 and the bottom surface of the method frame 4 in which the grout 6 filled in the diameter φ1 penetrates to the outside in the hole as shown in FIG. When close contact occurs and the ground surface erodes and sinks due to frost heaving or rain, a gap is created between the bottom of the frame and the ground surface. However, since the hardened grout head is in close contact with the bottom surface of the frame, the compressive stress transmitted to the frame is concentrated on the hardened grout head even if re-tensioning is applied to the ground anchor. For this reason, if the hardened grout head formed in a columnar shape in the soil does not buckle, or the ground surface is removed by repairing the ground by removing the frame and excavating the expanded hole diameter φ3 range of the grout head. It has a cross-sectional structure in which anchor force is not transmitted to the ground surface unless it is repaired smoothly and re-tensioned.

  In addition, since the ground anchor sliding sheath 5 of the free length portion L1 is set up to the sliding surface G3 of the lower portion of the free length portion L1, the ground is suddenly softened and fluidized due to heavy rain and the like, and the frame 4 When the ground surface bulges and fluidizes, the effect of tightening the soft ground between the frame 4 and the sliding surface G3 is drastically reduced, and the ground anchor sheath 5 is located below (sliding surface G3). The grout columnar shape is damaged and distorted by the earth pressure P, and the retaining effect of the anchor body inclined to the valley side is greatly reduced.

  In addition, [Patent Document 1] “Anti-overturning construction method in which a movable device is attached to the ground anchor head” etc. is a countermeasure construction method for preventing a structure from rolling or overturning when an earthquake or the like occurs, and [ [Patent Document 2] “A method for fixing a frame to a ground slope with a ground anchor” is a method of fixing a soft ground by a frame by setting a contraction device in a hole in the frame and a drilling hole in the ground. Although the cross-sectional structure is intended to promote, the plane cross section of the shrinkage device corresponds to the drilling diameter, and the grout penetrates into the surroundings depending on the soil condition, so there are many soils that have a larger diameter than the drilling diameter Depending on the soil condition, it may be difficult. Since the sliding sheath 5 of the free-length portion ground anchor is set up to the sliding surface G3 below the free-length portion L1, regardless of the soil quality of the sliding mass, the function of the anchor body depends on the frame 4 It has only a tightening effect, and when the ground frame of the anchor head is broken or the corrosion of the tightening device progresses, it has a cross-sectional structure in which all of the free-length soil blocks are in a dangerous state.

  [Non-patent literature] As shown in FIG. 5 (4), it is constructed with a conventional cross-sectional structure in which the sheath frame 9 is inserted into the hole φ 2 formed in the method frame 4 so that the method frame 4 can be removed. Although there is a case where the grout head is in close contact with the bottom of the frame, the anchor force T1 is concentrated as stress t1 on the grout head as in the cross-sectional structure diagram of FIG. Decreases and impedes the tightening of sliding soil blocks. As shown in FIG. 5 (5), it is a general cross-sectional structure that the grout 6 is also filled in the hole φ2 of the method frame 4, and improvement of the anchor method is desired.

JP 2008-150934 PR Japanese Patent Application No. 2009-148401

  In this way, when a gap is generated between the bottom surface of the frame and the ground, even if the ground anchor inserted into the drilling hole is re-tensioned, the filled grout head is cured and adheres to the frame and is integrated. Therefore, it is difficult to tighten the sliding mass. Also, as shown in Fig. 10 (4), when the soil block is softened and fluidized and the ground surface subsidizes, resulting in gaps or ground swelling on the bottom of the frame, the effect of the frame is reduced and drilling is performed. The inner ground anchor is bent at the boundary of the sliding surface G3 due to the earth pressure P, and the effect of tightening and retaining the soft ground by the ground anchor is reduced and the ground anchor function is lost.

  In the present invention, in order to enhance the effect of the anchor function, an independent expansion / contraction section is set so that the bottom surface of the frame 4 and the grout head are not in close contact with each other, and the length of the sliding sheath 5 for anchoring is shortened. A method of a cross-sectional structure in which an L4 section without the sheath 5 is set in the section of the free length L1 so as to be an upper surface from the surface G3, and the effect of tightening the sliding soil block by the method frame 4 and the retaining effect by the anchor body L2 section are promoted This is a frame fixing method. The stretchable section and the L4 section without the sheath 5 are integrated with each other, and the length of the L4 section is adjusted according to the soil condition, but it is difficult to enhance the effect of the anchor function sufficiently even if one of them is missing.

The gist of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 shows a cross-sectional structure diagram of a conventional general ground anchor method. A ground anchor having a sheath 5 for sliding a ground anchor on a bottom surface of a method frame 4 and a free length L1 section in a bore φ1. 1 shows a cross-sectional structure in which 1 is inserted, the grout 6 is filled, and the anchor body L2 is fixed. From such a cross-sectional structure, the bottom surface of the method frame 4, the hole diameter φ1, and the grout head having an enlarged diameter φ3 in which the grout penetrates and expands from the hole diameter φ1 are in close contact. Therefore, when the ground surface G1 sinks due to erosion or the like and the ground surface descends to G2, the anchor that the frame 4 transmits to the frame 4 is transferred to the grout head that has hardened in a columnar shape in the drilling hole in the soil. The force T1 concentrates as the stress t1, and has a cross-sectional structure in which the anchor force T1 is not transmitted into the ground, leading to a decrease in the ground anchor function.

  Moreover, when the ground anchor head clamping device is damaged, the entire sliding soil block in the free length section L1 is exposed to a risk of flowing down.

  For this reason, FIG. 3 (1) shows a situation in which an expansion / contraction section separated by the elastic material A1 is set so that the hardened grout head having the diameter 4 and the hole diameter φ3 and the hole diameter φ2 is not in close contact with each other. ing. 3 (2) shows that the ground surface G1 of FIG. 3 (1) sinks to become the ground surface G2, so that the ground anchor T1 is re-tensioned and the method frame 4 compresses the elastic body A1, and the bottom surface of the method frame 4 Shows a situation where the anchor function has been secured by showing a state where the pressure is pressed to the ground surface G2.

  FIG. 5 (1) shows an enlarged cross-sectional view of the ground anchor head of FIG. 3 (1) according to claim 2, wherein the expansion and contraction section is defined by the elastic body material A1 whose planar shape is the hole diameter φ3 and the thickness H1. The secured situation diagram is shown.

  FIG. 5 (2) shows an enlarged cross-sectional view of the ground anchor head according to claim 3. From the thickness H4 in consideration of the surface shape of the expanded hole diameter φ3 and the amount of settlement such as erosion of the ground surface as the expansion / contraction section. The sectional structure figure which constituted the space of the crevice which constitutes in the bottom of the frame is shown.

  FIG. 5 (3) shows an enlarged cross-sectional view of the ground anchor head according to claim 4, which is composed of a thickness H4 in consideration of the planar shape of the expanded hole diameter φ3 and the amount of settlement such as erosion of the ground as an expansion / contraction section. The cross-sectional structure figure which set the expansion-contraction sheath 4 is shown.

  FIG. 7 shows an example of a method for setting an expansion / contraction section when there are a plurality of ground anchors. FIG. 8 shows a cross-sectional shape at a position cc in FIG. 7 and sets an expansion / contraction section on the ground anchor head. It shows the method of fixing the frame to prevent the sliding soil block and promote the tightening effect.

  FIG. 9 shows a cross-sectional structure diagram in which expansion and contraction sections and a sheath 5 are set on a rocky rock anchor having no soft ground to promote the efficiency of the ground anchor method.

FIG. 10 (1) shows an overall cross-sectional view for explaining the outline of the embodiment of the present invention. In the grout head, the elastic material A1 and the anchor sliding sheath 5 are set as the L3 section as the expansion / contraction section, and the grout filling is performed. It is a situation figure in a state where no tension is applied to the ground anchor 1 yet.
FIG. 10 (2) is an embodiment of the present invention in which the ground anchor is tensioned after the grout filled in FIG. 10 (1) is hardened. The tension force T1 is applied to the ground surface through the frame 4 and is subjected to the pressure stress t2. A cross-sectional view of the whole showing concretely the tightening range (normal frame bottom width B1, sliding surface width B2) in the soft ground in the free-length portion L1 section, distributed as stress t3 in the soft ground It shows the tightening effect of the shaded area.

  FIG. 10 (3) shows the general anchor method so far in the overall view of FIG. 1, and shows a cross-sectional structure in the case where no expansion / contraction section is set in the grout head. This is an overall cross-sectional view that specifically shows the tightening range in the soft ground in the section of the free length L1 when tension T (tension force) is applied to the anchor. The grout head is in close contact with the bottom of the frame 4 Therefore, the anchor force T1 passes through the normal frame 4 and becomes a stress t1 on the grout head, and is concentrated on the columnar head having an enlarged diameter φ3, and has a cross-sectional structure that hardly transmits to the ground surface. When the ground surface G1 sinks and descends to G2 as shown in FIG. 1, a gap is confirmed on the bottom surface of the normal frame.

  FIG. 10 (4) shows a situation where the cross-sectional structure of FIG. 10 (3) is weakened due to heavy rain or the like so that the sliding soil mass flows down and the ground anchor is bent and broken. The damaged part is the position of the sliding surface G3 having the sliding sheath 5 of the ground anchor, and the ground anchor 1 is covered with the sliding anchor 5 of the ground anchor so that the ground anchor 1 can slide in the sheath. 6 is not integrated, and the section L3 is in a situation where it is not possible to suppress the slip of the soil block by the tensile force T2 of the anchor body L2 section.

  FIG. 10 (5) is an overall view of the cross-section anchor of the present invention shown in FIG. 10 (2). Like FIG. 4, the ground suddenly softens due to heavy rain and the ground surface sinks, or erodes due to flow down, frost heave, etc. If the amount of subsidence is more than the elongation due to the tension of the anchor, the tightening function by the anchor force T1 is drastically reduced, and at the lower end of the L3 where the ground anchor sliding sheath 5 is set, at the upper part of the L4 section It shows a situation where it was bent and damaged. In addition, since the sliding sheath 5 of the ground anchor is not set in the L4 section, the ground anchor and the grout are integrated and remain in the state of a convex concrete pile in the soil, and the tensile force T2 of the anchor body L2 section is It shows the situation where there was no damage by acting.

  In the present invention, as described above, an expansion / contraction section is set between the bottom surface of the method frame and the grout head so that an expanded diameter range is assumed. Therefore, the stress t1 is concentrated on the grout head where the anchor force T1 is cured through the method frame. Without doing so, the frame is lowered and the ground surface is pressure-bonded, and the anchoring force is dispersed in the soil, and the tightening effect of the sliding soil mass is promoted. In addition, by adjusting the sheath length of the ground anchor according to the soil condition and configuring it as the effect of the expansion and contraction section and the front and back, the tightening effect of the sliding soil mass by the anchor force T1 and the retaining effect by the tensile force T2 of the anchor body are improved. This is a method of fixing the frame by setting an expansion / contraction section on the anchor head and adjusting the sheath length to promote the anchor effect.

  Further, in the inventions according to claims 2, 3, and 4, the shape of the stretchable section of the present invention is a simple structure and the material can be handled by a simple material, and is an economical cross-sectional structure, but the object of the great effect of the ground anchor method is It has become an invention that promotes. The cross-sectional structure of the expansion / contraction section is a flat cross-section considering the expansion diameter φ3 in which the grout 6 filled in the drilling diameter φ1 penetrates and expands into the sliding soil mass, and the thickness H is a thickness considering subsidence due to erosion of the ground. It has a simple cross-sectional structure secured.

  How to carry out the present invention will be briefly described with reference to the drawings showing the operation of the present invention.

  Insert the ground anchor 1 so that the sliding sheath 5 of the ground anchor 1 is set in the L3 section of the ground anchor into the hole diameter φ1, fill the grout 6, and expand and contract before attaching the frame 4 A telescopic member is set in the hole, penetrating the hole φ2 in the anchoring member such as the anchorage frame 4, and the anchoring member 4 is attached to the ground slope. For this reason, the bottom surface of the locking member 4 and the hardened grout head are not in close contact with each other, and the anchoring force is not concentrated on the hardened grout head. .

  Further, since the tightening effect by the anchor force T1 is weakened near the sliding surface G3 of the sliding soil mass, the length of the sliding sheath 5 of the ground anchor 1 is adjusted, and the tensile force T2 of the anchor body directly suppresses the sliding soil mass. An L4 section where the sheath 5 is not set is set on the upper part of the sliding surface G3 so as to correspond. In the L4 section and the L2 section where the sheath 5 is not set, the grout 6 is adhered and hardened to the anchor 1 and the periphery of the drilling diameter φ1 is adhered and integrated with the ground. Therefore, the tensile force t2 of the anchor body can be used. It is possible to increase the coefficient of friction of the sliding surface G3 and suppress the slip of the soil block, thereby promoting the efficiency of the anchor method.

  Furthermore, even if the ground surface on the bottom of the frame is settling down suddenly due to heavy rain and the re-tensioning work is not in time, and the frame 4 is damaged as shown in FIG. 10 (5), the column-shaped hole diameter φ3 is anchored in the L4 section. A shearing force generated by the body's tensile force T2 is generated to resist the earth pressure P, and it is possible to suppress slipping of the earth block in the hatched portion of the L4 section. The length of the L4 section is set shorter if it is rocky, and longer if it is clayey, depending on the soil conditions.

  Specific embodiments of the present invention will be described with reference to the drawings.

  As an embodiment described in claim 2, as shown in FIG. 3 (1), an expansion / contraction section is set on the bottom surface of the frame 4 and the hardened grout having a hole diameter φ1 or a hole diameter φ3 is separated by an elastic material A1, and the free length portion FIG. 5 (1) shows an enlarged view of the upper part of FIG. 3 (1). FIG. 5 (1) shows a sectional structure diagram in which the sheath 5 is set in the L3 section in L1. The cross-sectional shape and the like of the elastic body material A1 depend on the soil condition depending on the field conditions, but are set at about φ3≈20 to 30 cm and H1≈10 to 20 cm, respectively. Any material that is elastic, watertight, and resistant to corrosion may be used.

  FIG. 5 (2) as the present embodiment according to claim 3 shows an enlarged cross-sectional view of the ground anchor head, taking into consideration the surface shape of the expanded hole diameter φ 3 and the amount of settlement such as erosion of the ground surface as the expansion and contraction section. The sectional structure figure which constituted the space of the crevice which consisted of thickness H4 to the bottom of the frame was shown. When the ground surface softens and sinks, it is constructed at the bottom of the frame so that the hardened columnar hole diameter φ3 can be inserted into the recessed space at the bottom of the frame 4, and the cross-sectional shape is determined from the situation at the site. Depending on the soil condition, it is set to φ3 ≒ 20-30cm and H4 ≒ 10-20cm respectively, and the space of the recess is filled with elastic or elastic rubber material or foaming material according to the site situation There is no problem.

  FIG. 5 (3) as the present embodiment according to claim 4 shows an enlarged cross-sectional view of the ground anchor head, taking into account the surface shape of the expanded hole diameter φ 3 and the amount of settlement such as erosion of the ground as the expansion and contraction section. The cross-section figure which set the expansion-contraction sheath 4 which consists of thickness H1 is shown. The cross-sectional shape and the like depend on the soil condition depending on the site conditions, but are set at φ3≈20 to 30 cm and H1≈10 to 20 cm, respectively. The expansion sheath 4 has a bellows structure, but the material may be any material having elasticity, elasticity, and water tightness, and may be rubber or steel, and the number and shape of the bellows are also elastic. The material is not specified as long as it has. Moreover, there is no problem even if the space in the pipe is filled with a rubber material or a foam material that has elasticity and can be expanded and contracted depending on the situation at the site.

  In the L4 section of FIG. 10 (2) where the ground anchor sliding sheath 5 of the present invention is not applied, the anchor body itself does not expect the tightening effect of the frame work. Is set as a section that resists the earth pressure P as a columnar object in the hardened soil. When the re-tensioning work is not in time, the anchor body is in good health. Therefore, since the diameter of the expanded diameter φ3 section of the L4 section without the sheath 5 is integrated with the anchor 1 and the grout 6, the convex protrusion on the sliding surface. It is a cross-sectional structure that suppresses the slipping of soft snow layers by installing piles on the slopes of heavy snow regions. However, since the ground anchor 1 and the grout 6 are not in close contact with each other at the position where the sheath 5 is present, it is difficult to receive the anchoring effect of the anchor body, and the L3 section where the sheath 5 is present is bent.

  The L4 section without the sheath resists the sliding earth pressure P, and even if the anchoring force T1 is drastically reduced, it is possible to suppress the slipping of the soil mass by the tensile force T2 of the anchor body L2. Although the height of the L4 section is about 1 to 3 m depending on the soil quality, it significantly increases the frictional resistance of the sliding surface G3 and has a great effect on inhibiting the slippage of the clot. It led to deterrence. The present invention uses the anchor force T1 and the tensile force T2 of the anchor body L2 as the front and back sides to promote the effect of the ground anchor method. This is a method of fixing the frame to promote the ground anchor effect.

・ ・ An example of a cross-sectional view of a conventional ground anchor method. ..Explanation plane sectional view of FIG. FIG. 2 (1)... FIG. 2 (2) .. FIG. .. Cross-sectional view according to claim 1 of the present invention. FIG. 3 (1). FIG. 3 is a cross-sectional view of a situation in which an elastic material A1 is set as an expansion / contraction section in the anchor head, and an anchor sliding sheath length L3 is set in the free length L1. 3 (2) .. The ground surface G1 in FIG. 3 (1) sinks due to erosion, etc., descends to G2, the elastic body material A1 is compressed by the re-tensioning of the ground anchor 1, and the frame 4 descends by H3 to reduce the thickness. An example of a cross-sectional view of a situation where (H1> H2) is obtained is shown. .. Each explanatory plane sectional view of FIG. 3 (1) and FIG. 3 (2). FIG. 4 (1)... FIG. 4B is a cross-sectional view at the bb position. FIG. 4 (3).. ..Enlarged sectional view of the grout head. FIG. 5 (1): An enlarged cross-sectional view of the anchor head of FIG. 3 (1) according to claim 2. FIG. 5 (2): An enlarged cross-sectional view of the anchor head according to claim 3. FIG. 5 (3): An enlarged sectional view of the anchor head according to claim 4. FIG. 5 (4): An enlarged cross-sectional view of an anchor head using a conventional general sheath rod 9. FIG. 5 (5): An enlarged cross-sectional view of the anchor head in which the grout is filled in the anchor hole φ 2 of the conventional general frame 4. ..Explanation plane sectional view of FIG. 6 (1)... Sectional view taken along the line dd in FIG. 5 (2). FIG. 6B is a cross-sectional view taken along the line cc in FIG. -An enlarged sectional view of the head when there are a plurality of ground anchors 1 according to claim 2. ..Cross sectional view at the position of FIG. .. Cross-sectional structure diagram when elastic body material A1 is set as an expansion / contraction section on a grout head such as a rock bolt method. ..A cross-sectional view of the entire slope for specifically explaining the present invention. FIG. 10 (1).. Whole cross section according to claim 1 of the present invention. The whole cross section according to claim 1 which shows the tightening range after tensioning the ground anchor of Drawing 10 (2) and Drawing 10 (1). FIG. 10 (3). FIG. 10 is a cross-sectional view of the whole when the sliding sheath of the ground anchor is set in the L <b> 1 section without setting the expansion / contraction section in the grout head in the conventional general anchor method. FIG. 10 (4) .. FIG. 10 (3) is an overall cross-sectional view showing a damage situation in the case of being damaged. FIG. 10 (5). FIG. 10 (2) is an overall cross-sectional view showing the state of breakage when the anchor method of the present invention is damaged by FIG. 10 (2).

1. Ground anchor 2 ... Tightening nut 3 ... Supporting plate 4 ... Leg frame 5 ... Ground anchor sliding sheath 6 ... Grout 7 ... Strand anchor 8 ... Anchor wedge 9 ... Sheath rod A1 · · Elastic body material A2 for expansion and contraction · Concave surface A3 at the bottom of the expansion and contraction frame · · B1 with expansion and contraction bellows · · B2 the width of the frame to be pressed against the ground Range that intersects the plane G3.
H1 ··· Thickness H2 of elastic material A1 for expansion and contraction · · Thickness H3 after compression of elastic material A1 for expansion and contraction · H4 amount of sinking of frame 4 · · · of concave surface A2 at the bottom of the frame for expansion and contraction Thickness G1 ·· Ground surface G2 ·· L1 surface eroded and subsided L1 ·· Free length L2 of ground anchor ·· Anchor body length of anchor (fixed portion of anchor)
L3 ··· A section L4 in which the sheath 5 for ground anchor sliding is set in the free length L1 · · A section L5 in which there is no ground anchor sliding sheath in the free length L1 · · the ground anchor length P of the rock bolt · · earth pressure T1・ ・ Anchor pulling force T2 ・ ・ Pulling force t1 of anchor body ・ ・ Force t2 acting on the grout head through the normal frame 4 ・ ・ Anchor pulling force is transmitted to the ground surface G1 through the normal frame 4 Force t3 ・ ・ Anchor tension force is transmitted to the ground surface G1 through the normal frame 4 and is dispersed in the soil and acting on the influence range of tightening the soft ground φ1 ・ ・ Drilling hole diameter φ2 ・ ・ Forming in the normal frame Hole diameter φ3 ・ ・ Expanded hole diameter

Claims (4)

  In the frame fixing method, where anchor members such as frame and method are fixed to the ground slope with ground anchors, the stretch section is between the grout head filled in the ground drilling hole in the anchor free length section and the bottom of the frame. The length of the sheath is adjusted by adjusting the soil condition to improve the tightening effect of the sliding soil mass by the anchor force and the anchoring effect by the anchor body. A frame fixing method that adjusts the height and promotes the ground anchor effect.   A stretchable section is set on the bottom surface of the normal frame by setting an elastic body having a thickness in consideration of the surface shape of the expanded hole diameter and the amount of settlement such as erosion of the ground as the stretchable section according to claim 1. A frame fixing method that adjusts the length to promote the ground anchor effect.   The expansion / contraction section according to claim 1, wherein a recess space having a thickness in consideration of the surface shape of the expanded diameter and the amount of settlement such as erosion of the ground is formed at the bottom of the frame, and the expansion / contraction section is set at the bottom of the frame A frame fixing method that adjusts the length to promote the ground anchor effect.   The expansion / contraction section is set on the bottom surface of the normal frame by setting an expansion / contraction sheath with a thickness considering the surface shape of the expanded diameter and the amount of settlement such as erosion of the ground as the expansion / contraction section according to claim 1. A method of fixing the frame to adjust the ground anchor effect.

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