JP2010196390A - Underground structure crossing active fault zone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an underground structure crossing an active fault zone that does not impair a function as a structure against an anticipated slip between sliding surfaces. <P>SOLUTION: The underground structure T1 crossing the active fault zone includes a structure body 1 formed to cross the underground sliding surface (the active fault zone) F, and an outside tunnel 2 formed to surround the outer periphery of the structure body 1 in a crossing section A including the crossing part of the sliding surface F. The structure body 1 includes a crossing part structure 10 formed in the crossing section A, and a general part structure 11 formed in a general section B adjacent to the crossing section A. The crossing part structure 10 is supported at two points at the front and rear of the sliding surface F in the outside tunnel 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an underground structure that traverses an active fault zone that may cause a slip.

A linear structure such as a road, a railroad, or a waterway may be forced to cross an active fault zone that may cause a slip in setting a route.
Although the active fault motion cycle is much longer than the in-service period of the structure, there is a possibility that a large stress may act on these structures when slippage (displacement) occurs in the slip surface in the ground.

  When a large stress accompanying the slip plane displacement acts on the structure in this way, the structure may be damaged and may not be usable.

  In Patent Document 1 and Patent Document 2, the active fault zone is displaced by the space between the inner tunnel and the outer tunnel, where the active fault crossing point is a double tunnel. A receiving structure is disclosed.

Japanese Patent Application Laid-Open No. 2003-239691 JP 2006-233626 A

  In the double tunnel, the inner tunnel is supported by the damping damper, but the foundation of the damping damper is formed in the fault zone. For this reason, when a large shift occurs on the slip surface, excessive stress may act on the inner tunnel.

  From such a viewpoint, an object of the present invention is to propose an underground structure that traverses an active fault zone that does not impair the function as a structure with respect to a possible slip plane displacement.

  An underground structure that crosses the active fault zone of the present invention that solves such problems is a structure body formed to cross the active fault zone, and a cross section including a crossing point of the active fault zone. An outer tunnel formed to surround an outer periphery of the structure body, the structure body formed in a cross section structure formed in the cross section and a general section adjacent to the cross section. The cross section structure is supported at two points before and after the active fault zone in the outer tunnel.

  According to the underground structure traversing the active fault zone, when a slip displacement occurs in the active fault zone, the transverse structure supported at two points across the slip surface is inclined or swiveled as a whole. As a result, the step generated before and after the sliding surface is eliminated, so that the function as a structure can be maintained.

  If a flexible joint is interposed at the boundary between the transverse structure and the general structure, the boundary between the transverse structure and the general structure is formed by the inclination or turning of the transverse structure. It is possible to prevent the portion from being damaged.

The support structure for the crossing structure of the underground structure that crosses the active fault zone may be a hanging type or a mounting type.
According to the underground structure that crosses the active fault zone, the space secured between the outer tunnel and the transverse structure prevents the influence of the displacement of the ground from directly acting on the transverse structure. Therefore, the structure main body can be prevented from becoming unusable.

  If the crossing structure is a bridge, it is possible to construct a crossing structure that does not necessarily have a tubular shape, such as a railroad or a road, relatively easily.

  The underground structure traversing the active fault zone may be one in which the crossing structure is supported in two regions before and after the active fault zone in the outer tunnel.

  According to the underground structure that traverses the active fault zone of the present invention, even if slip displacement occurs in the active fault zone, it can be used continuously without impairing its function as a structure.

It is a longitudinal cross-sectional view which shows the underground structure which crosses the active fault zone which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the condition of the underground structure which crosses the active fault zone of FIG. 1 when the shift | offset | difference in a slip surface arises. It is a figure which shows the underground structure which crosses the active fault zone which concerns on 2nd Embodiment, (a) is a longitudinal cross-sectional view, (b) is an exploded view which shows the detail of a support structure, (c) is It is a longitudinal cross-sectional view which shows the condition when the shift | offset | difference in a slip surface has arisen. (A) The longitudinal cross-sectional view which shows the underground structure which crosses the active fault zone which concerns on 3rd Embodiment, (b) is a modification of the underground structure which crosses the active fault zone shown to (a) It is. It is a figure which shows the underground structure which crosses the active fault zone which concerns on 4th Embodiment. (A) And (b) is a longitudinal cross-sectional view which shows the modification of suitable embodiment of this invention.

  An underground structure (hereinafter simply referred to as “underground structure”) T1 that crosses the active fault zone according to the first embodiment is a railway tunnel, and as shown in FIG. The structure body 1 formed so as to cross the internal slip surface (active fault zone) F, and the outer periphery of the structure body 1 is formed in the cross section A including the crossing portion of the slip surface F. And an outer tunnel 2.

The structure body 1 includes a crossing structure 10 formed in the crossing section A and a general structure 11 formed in the general section B adjacent to the crossing section A.
A flexible joint 12 is interposed at the boundary between the crossing structure 10 and the general structure 11.

  The transverse structure 10 is a tunnel formed in the inner space of the outer tunnel 2, and is supported by support members 13 formed at two locations in the outer tunnel 2.

  The crossing structure 10 is a cylindrical structure having an inner hollow section having the same shape as the general structure 11. The transverse structure 10 of the present embodiment is stiffened so as to withstand two-point support, so that the outer diameter is larger than the outer diameter of the general structure 11.

  The construction method of the crossing structure 10 is not limited and can be appropriately performed. For example, it may be constructed by on-site concrete, or may be constructed by combining precast members.

The general part structure 11 is a tunnel formed in the general section B, and is formed to have an inner air cross section necessary for a railway tunnel.
The construction method of the general part structure 11 is not limited, and may be appropriately performed, such as NATM and TBM method.

  The flexible joint 12 is a joint that connects the transverse structure 10 and the general structure 11 so as to extend and contract and rotate freely.

  The flexible joint 12 is made of a ring-shaped material or structure having flexibility and stretchability, and has a hollow cross section having the same shape as the tunnel that forms the transverse structure 10 and the general structure 11. It is formed in a shape. The outer diameter of the flexible joint 12 is tapered so that the outer surfaces of the transverse structure 10 and the general structure 11 are rubbed together. In addition, the shape dimensions of the flexible joint 12 are not limited. Further, the connection between the transverse structure 10 and the general structure 11 is not necessarily performed by a joint having flexibility and stretchability.

The support member 13 is a member that suspends the crossing structure 10 in the outer tunnel 2, and is disposed at two locations across the sliding surface F. In the present embodiment, the interval between the support members 13 is several tens of meters or more.
The arrangement of the support member 13 is not limited as long as the support member 13 is arranged with the sliding surface F interposed therebetween.

  Although the structure of the support member 13 is not limited, in this embodiment, it is provided with the anchor part 13a, the joint part 13b, and the holding | maintenance part 13c.

  The anchor part 13a is composed of a plurality of anchor members embedded in the ground G, and suspends the holding part 13c via the joint part 13b.

  The joint portion 13b is a member that connects the anchor portion 13a and the holding portion 13c, and has a configuration capable of suspending the transverse portion structure 10 even when the transverse portion structure 10 is inclined or the like. . In the present embodiment, the joint portion 13b is configured by a cable.

  The holding part 13c is a member that holds the crossing structure 10 and is fixed to the crossing structure 10 by being wound around the outer periphery of the crossing structure 10 in this embodiment.

  The outer tunnel 2 is a widened tunnel formed so as to surround the outer periphery of the structure body 1 in the transverse section A. That is, the underground structure T <b> 1 according to the present embodiment forms a double structure in the cross section A by the cross structure 10 (structure body 1) and the outer tunnel 2.

Both ends of the outer tunnel 2 communicate with the general part structure 11.
The outer tunnel 2 is covered with a waterproofing / drainage (for example, a waterproof sheet and a water-permeable cushioning material) to prevent leakage of groundwater into the interior.

  The construction method of the outer tunnel 2 is not limited, and may be appropriately selected such as NATM or TBM method.

  Further, the support structure of the outer tunnel 2 is not limited, and may be appropriately performed. In addition, the construction of the outer tunnel 2 is performed by using an auxiliary construction method as necessary, such as the ground G in the cross section A is a soft ground including an aquifer.

  As described above, according to the underground structure T1 according to the first embodiment, as shown in FIG. 2, even if the displacement of several meters is caused due to the slip surface F or the like, the underground structure The function as the object T1 can be maintained.

  Since a sufficient gap is formed between the outer tunnel 2 and the crossing structure 10, it is possible to prevent the stress accompanying the slip displacement of the ground G from directly acting on the crossing structure 10.

  Since the transverse structure 10 is supported at two support points (support members 13) separated by several tens of meters or more, even if a displacement in units of several meters occurs on the sliding surface F, a gentle inclination It is possible to suppress the displacement to such an extent that the phenomenon occurs.

  In addition, the flexible joint 12 interposed between the transverse structure 10 and the general structure 11 has stretchability and flexibility, so that the transverse structure 10 is inclined. Even so, the connection between the crossing structure 10 and the general structure 11 is maintained.

  Moreover, since the joint part 13b is comprised with the cable, the support member 13 is capable of suspending the crossing structure 10 without hindering displacement of the crossing structure 10 such as an inclination.

An underground structure (hereinafter simply referred to as “underground structure”) T2 crossing the active fault zone of the second embodiment is a railway tunnel, and as shown in FIG. The structure main body 1 formed so as to cross the internal slip surface (active fault zone) F, and the outer periphery of the structure main body 1 is formed in the cross section A including the crossing portion of the slide surface F. And an outer tunnel 2.
The underground structure T2 according to the second embodiment is an underground structure T1 according to the first embodiment that is a suspension type in that the support type of the crossing structure 10 is a mounting type. (See FIG. 1).

The structure body 1 includes a crossing structure 10 formed in the crossing section A and a general structure 11 formed in the general section B adjacent to the crossing section A.
A flexible joint 12 is interposed at the boundary between the crossing structure 10 and the general structure 11.

  Since the structure of the crossing part structure 10, the general part structure 11, and the flexible joint 12 is the same as that shown in the first embodiment, detailed description thereof is omitted.

The crossing structure 10 is supported in the outer tunnel 2 via supports 14 formed at two locations across the sliding surface F. In this embodiment, the interval between the supports 14 is several tens of meters or more.
In addition, the arrangement | positioning of the support 14 will not be limited if it is arrange | positioned on both sides of the sliding surface F. As shown in FIG.

  Although the structure of the support 14 is not limited, in this embodiment, it is comprised including the base part 14a, the pin support part 14b, and the holding | maintenance part 14c.

  As shown in FIG. 3B, the pedestal portion 14a is a member disposed at the bottom of the outer tunnel 2, and has an upper surface formed in a spherical shape. The pedestal portion 14a may be fixed to the ground G via an anchor or the like.

The pin support portion 14b has a spherical (spherical crown) concave portion formed on the bottom portion corresponding to the upper surface of the pedestal portion 14a, and slides on the upper surface of the pedestal portion 14a.
The upper surface of the pin support portion 14b (the contact surface with the holding portion 14c) is formed flat, and a low friction material (low friction sheet, slip surface plate, etc.) 14d is disposed on the surface (upper surface).

The holding part 14c is a member that holds the crossing part structure 10, and in this embodiment, the holding part 14c is mounted around the outer periphery of the crossing part structure 10 to fix the crossing part structure 10.
The contact surface of the lower surface of the holding portion 14c with the pin support portion 14b is formed flat, and the low friction material 14d is disposed on the surface.

The outer tunnel 2 is a widened tunnel formed so as to surround the outer periphery of the structure body 1 in the transverse section A. That is, the underground structure T <b> 2 according to the present embodiment forms a double structure in the cross section A with the cross structure 10 (structure body 1) and the outer tunnel 2.
The configuration of the outer tunnel 2 is the same as that shown in the first embodiment, and a detailed description thereof is omitted.

  As described above, according to the underground structure T2 according to the second embodiment, as illustrated in FIG. It becomes possible to maintain the function as the underground structure T2.

  Further, since the support 14 is supported by the pedestal portion 14a so that the pin support portion 14b can rotate and tilt, and the holding portion 14c is slidably held, the displacement of the transverse structure 10 can be changed. The crossing structure 10 is supported without hindering.

  Since the operational effects of the underground structure T2 of the other second embodiment are the same as those of the underground structure T1 of the first embodiment, detailed description thereof is omitted.

  An underground structure (hereinafter simply referred to as “underground structure”) T3 crossing the active fault zone of the third embodiment is a railway tunnel, and as shown in FIG. The structure body 1 formed so as to cross the internal slip surface (active fault zone) F, and the outer periphery of the structure body 1 is formed in the cross section A including the crossing portion of the slip surface F. And an outer tunnel 2.

The underground structure T3 according to the third embodiment is a first structure that constructs a tunnel as the crossing structure 10 in that a bridge is built in the outer tunnel 2 as the crossing structure 10 ′. This is different from the embodiment.
A flexible joint 12 is interposed at a boundary portion between the crossing structure 10 ′ and the general structure 11.

  The transverse structure 10 'is supported by support members 13 formed at two locations in the outer tunnel.

  In this embodiment, a truss-type bridge is adopted as the crossing structure 10 ', but the type of the bridge constituting the crossing structure 10' is not limited.

  Since the structure of the general part structure 11 is the same as that shown in the first embodiment, a detailed description thereof will be omitted.

  The flexible joint 12 is a joint that connects the transverse structure 10 'and the general structure 11 so as to extend and contract and rotate freely.

The flexible joint 12 has a yield strength that allows passage of a railway vehicle, and is formed by forming a flexible and stretchable material into a plate shape.
Note that the joint that connects the crossing structure 10 ′ and the general structure 11 does not necessarily need to be the flexible joint 12.

The crossing structure 10 ′ is suspended in the outer tunnel 2 via support members 13 formed at two locations across the sliding surface F. In the present embodiment, the interval between the support members 13 is several tens of meters or more.
In addition, since the structure of the supporting member 13 is the same as the content shown in 1st Embodiment, detailed description is abbreviate | omitted.

  In the present embodiment, the crossing structure 10 ′, which is a bridge, is a suspension support structure that is suspended in the outer tunnel 2 via the support member 13. However, as shown in FIG. 14 may be a mounting-type support structure.

  Since the configuration of the outer tunnel 2 is the same as that shown in the first embodiment, detailed description thereof is omitted.

As mentioned above, according to the underground structure T3 which concerns on 3rd Embodiment, the effort which constructs a cylindrical tunnel by the assembly of a formwork, concrete placement, etc. in the outer side tunnel 2 is abbreviate | omitted, and it is simpler. It is possible to construct the underground structure T3 that crosses the slip surface.
Moreover, since the crossing structure 10 ′ is opened in the outer tunnel 2, maintenance can be performed more easily.

  Since the operational effects of the underground structure T3 according to the other third embodiment are the same as those of the underground structure T1 according to the first embodiment, detailed description thereof is omitted.

  An underground structure (hereinafter simply referred to as “underground structure”) T4 that crosses the active fault zone according to the fourth embodiment is a railway tunnel, and as shown in FIG. The structure main body 1 formed so as to cross the plane (active fault zone) F, and the outer tunnel 2 formed so as to surround the outer periphery of the structure main body 1 in the cross section A including the crossing portion of the sliding surface F And.

  In the underground structure T4, the crossing structure 10 is supported in two regions (first support region 15 and second support region 16) before and after the sliding surface F in the outer tunnel 2.

  Since the structure of the general part structure 11 and the flexible joint 12 of the fourth embodiment is the same as the contents shown in the second embodiment, detailed description thereof is omitted.

  Here, the first support region 15 and the second support region 16 are regions having a predetermined distance. Between the first support region 15 and the second support region 16, a non-supporting region 17 that is not supported from the outer tunnel 2 is provided.

  The non-supporting region 17 is provided so as to straddle the sliding surface, and is ensured by several tens of meters or more. The non-supporting region 17 secures a distance that is at least half of the extension distance of the transverse structure 10. In addition, arrangement | positioning of the 1st support area | region 15 and the 2nd support area | region 16 will not be limited if it is arrange | positioned on both sides of the sliding surface F. As shown in FIG.

  In the present embodiment, the support type of the crossing structure 10 in the first support region 15 (one region) and the second support region 16 (the other region) is a mounting type. In addition, the support structure of the crossing structure 10 in each support area | region 15 and 16 is not limited.

  In the first support region 15, a plurality (three in this embodiment) of supports 14, 14, 14 are formed, and the crossing structure 10 is supported at multiple points. In the present embodiment, the supports 14, 14, and 14 are continuously provided at a predetermined interval in the tunnel axis direction, but the arrangement of the supports 14, 14, and 14 is not limited. Moreover, the number of the supports 14 in the 1st support area | region 15 is not limited, It is possible to set suitably.

The second support region 16 is supported at a single point via a single support 14.
In addition, since the structure of the support 14 arrange | positioned in the 1st support area | region 15 and the 2nd support area | region 16 is the same as the structure shown in 2nd Embodiment, detailed description is abbreviate | omitted.

  In the present embodiment, a plurality of supports 14, 14 and 14 are arranged in the first support area 15, and a single support 14 is arranged in the second support area. For example, both areas have a plurality of supports 14 in both areas. For example, the number of supports arranged in each region and the support type are not limited.

The outer tunnel 2 is a widened tunnel formed so as to surround the outer periphery of the structure body 1 in the transverse section A. That is, the underground structure T4 according to the present embodiment forms a double structure in the cross section A by the cross section structure 10 (structure main body 1) and the outer tunnel 2.
The configuration of the outer tunnel 2 is the same as that shown in the second embodiment, and a detailed description thereof is omitted.

  As described above, according to the underground structure T4 according to the fourth embodiment, the function as the underground structure T4 is maintained even when a displacement of several meters occurs due to the slip surface F or the like. It becomes possible to do.

  Further, since the first support region 15 is supported at multiple points by the plurality of supports 14, 14, 14, the acting stress of the first support region 15 is dispersed by the supports 14, 14, 14. Therefore, even if a large displacement due to slippage of the sliding surface F or the like occurs, the applied stress is not concentrated at one point, and the transverse structure 10 and the bearing 14 are prevented from being damaged. The in-service state of the body 10 can be maintained.

  Further, since the support 14 is supported by the pedestal portion 14a so that the pin support portion 14b can rotate and tilt, and the holding portion 14c is slidably held, the displacement of the transverse structure 10 can be changed. The crossing structure 10 is supported without hindering.

  Since the operational effects of the underground structure T4 of the other fourth embodiment are the same as those of the underground structure T2 of the second embodiment, detailed description thereof is omitted.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and it goes without saying that the above-described constituent elements can be appropriately changed in design without departing from the spirit of the present invention.
For example, in each of the embodiments described above, the case where the underground structure crossing the active fault zone of the present invention is adopted for the railway tunnel has been described. However, the purpose of using the underground structure crossing the active fault zone is limited. It is not something.

  In each of the above embodiments, the crossing structure 10 is constructed by a tunnel or a bridge. However, a crossing structure such as an underground structure T5 that crosses the active fault zone shown in FIG. A structure in which the inner tunnel 10 a is supported by the inner bridge 10 b as the body 10 may be constructed in the outer tunnel 2. According to the underground structure T5 that crosses the active fault zone, since the inner tunnel 10a is supported by the inner bridge 10b, it is possible to reduce the thickness of the member of the inner tunnel 10a. The material cost can be reduced.

  Moreover, a suspension bridge type may be adopted as a type of bridge constructed in the outer tunnel 2 as in the underground structure T5 shown in FIG. 6 (b).

DESCRIPTION OF SYMBOLS 1 Structure main body 10 Transverse structure 11 General structure 12 Flexible joint 13 Support member 14 Support 2 Outer tunnel A Cross section B General section F Sliding surface (active fault zone)
G Ground T1, T2, T3, T4, T5 Underground structure

Claims (6)

An active fault comprising: a structure main body formed so as to cross the active fault zone; and an outer tunnel formed so as to surround an outer periphery of the structure main body in a cross section including a crossing point of the active fault zone An underground structure that crosses the belt,
The structure body includes a cross section structure formed in the cross section, and a general section structure formed in a general section adjacent to the cross section,
The underground structure crossing the active fault zone is characterized in that the crossing structure is supported at two points before and after the active fault zone in the outer tunnel.   The underground structure crossing an active fault zone according to claim 1, wherein a flexible joint is interposed at a boundary portion between the crossing structure and the general structure.   The underground structure traversing the active fault zone according to claim 1 or 2, wherein a support structure of the transverse structure is a suspension type.   The underground structure crossing the active fault zone according to claim 1 or 2, wherein the support structure of the crossing structure is a mounting type.   The underground structure crossing the active fault zone according to any one of claims 1 to 4, wherein the crossing structure is a bridge. An active fault comprising: a structure main body formed so as to cross the active fault zone; and an outer tunnel formed so as to surround an outer periphery of the structure main body in a cross section including a crossing point of the active fault zone An underground structure that crosses the belt,
The structure body includes a cross section structure formed in the cross section, and a general section structure formed in a general section adjacent to the cross section,
The underground structure crossing the active fault zone, wherein the crossing structure is supported in two regions before and after the active fault zone in an outer tunnel.

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