Water catch basin

Abstract

This invention provides a manhole facility installed underground for use in the maintenance and management of underground utilities such as electricity, water and sewage systems, and gas lines, as well as for branching such utilities and for storing water and other materials, and for use as a tank or similar container, which allows for efficient transportation to the site during construction and repair work, and facilitates on-site construction. [Solution] The present invention provides a manhole facility to be installed underground, which includes vertical panels that constitute the exterior wall and connecting devices that connect the left and right ends of the vertical panels, and are positioned so as not to generate tensile force on the connecting surfaces.

Description

[Technical Field]

[0001] This invention relates to catch basins used for water supply and drainage, and to handholes and manholes for managing underground structures. [Background technology]

[0002] For buried structures installed continuously underground, box- or box-shaped structures installed underground are indispensable due to the need for branching out in a branch-like manner inherent in the nature of the buried structures, as well as for management purposes. Concrete structures are the mainstream choice for reasons such as durability.

[0003] Due to the need to ensure quality and ease of construction, there is an invention of a cast-in-place concrete catch basin using prefabricated formwork (Japanese Patent Publication No. 08-082095). However, in recent years, the use of precast concrete products has become frequent in the construction of concrete structures due to the demand for high quality and uniform output, as well as the shortage of engineers and highly skilled workers at construction sites. Regarding the use of precast concrete products at construction sites, there is a need to reduce transportation costs to the site and the burden on workers at the site.

[0004] As a type of catch basin made of precast concrete products assembled on-site, there is a design in which the lower, middle, and upper basins are stacked and installed on-site in a vertical direction (Japanese Utility Model Publication No. S58-029683). There is a design in which four crank-shaped side walls are joined in a tomoe-like pattern using connecting fittings installed on the surface of the side walls (Japanese Utility Model Publication No. S61-130687). There is also an invention in which a U-shaped subunit and an end wall subunit are joined together for assembly (Japanese Patent Publication No. 2003-274546). In all of these proposals, the precast concrete products that are delivered to the site have problems such as inefficient transportation and delivery because the corners are manufactured in the factory.

[0005] As a rainwater storage and infiltration facility for assembling plate-shaped members with efficient transportation and loading, a water channel member is installed in a space secured by side plate members erected at intervals and a plurality of partition members provided therebetween (Japanese Unexamined Patent Application Publication No. 2009-024453). In this invention, in order to secure a water passage portion, it has a structure in which the pressing force due to the earth pressure on the side wall members is received by the partition members, and the number thereof varies depending on the magnitude of the earth pressure. Therefore, as a space for management, the partition members become obstacles.

[0006] As a prefabricated handhole, there is an invention in which a square cross-sectional member with a stepped notch at the end is stacked and assembled to secure a space in the ground (Japanese Unexamined Patent Application Publication No. 2001-211540). It is assembled by a connecting hole penetrating vertically at the center of the notch portion at the end and a connecting deformed reinforcing bar penetrating vertically between the plurality of connecting holes. However, no consideration has been given to the bearing capacity against the earth pressure in the soil, and it has been proposed as a structure in shallow ground.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0008] The problem to be solved is to propose a box-shaped facility such as a water collection box or a handhole installed underground, which is a secondary product with stable quality, and uses parts of the side wall of the box facility that are easy to assemble, install, transport, and carry in, and constructs them by assembling them to have a stable structure.

Means for Solving the Problem

[0009] A box facility installed underground and having an outer wall portion in contact with the ground and an inner space, The outer wall portion includes a standing plate or stacked plate erected upward, connected leftward or rightward, with the ground side as the front and the inner space side as the back, having left and right side surfaces and upper and lower surfaces, and a connecting tool for connecting the standing plate and another standing plate adjacent to it on the left or right, The standing plate has an abutting surface with the other adjacent standing plate on the back or left or right side at the left or right end, On the abutting surface of the back of the standing plate, there is a connecting tool insertion portion penetrating the standing plate, or on the abutting surface of the left or right side of the standing plate, there is a connecting tool receiving portion engaging with the end of the connecting tool inserted into the connecting tool insertion portion of the other adjacent standing plate, The connecting tool is a connecting tool capable of applying a compressive force so that no gap occurs at the abutting surface due to an external force from the ground side or the inner space side to the outer wall portion of the box facility.

Effect of the Invention

[0010] The present invention relates to a standing plate which is a plate-like body constituting the outer wall portion of a box facility underground and a connecting tool for connecting the standing plate. In a box facility made of a conventional precast product, transportation and installation are labor-intensive. The parts of the box facility of the present invention can be transported extremely efficiently, are easy to assemble and install on-site, and it is possible to install the facility according to external conditions for the box facility. The main external forces affecting underground manhole facilities are earth pressure and groundwater pressure from the ground side against the outer wall, and water pressure from the inner space side, which are different in direction from the self-weight of the manhole facility, which can be a large external force. Furthermore, external forces other than self-weight are perpendicular to the wall surface of the structure in plan view and are often nearly uniformly distributed at the same height. Therefore, the vertical panels can be relatively simple structures as structures that receive external forces. By applying compressive force to the contact surface using connecting devices, it is possible to prevent gaps between members caused by peeling stress generated by external forces on the vertical panels of the outer wall. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is an explanatory diagram of the underground manhole facility. (Example 1) [Figure 2] Figure 2 is an explanatory diagram of the connecting device for the underground manhole facility. (Example 1) [Figure 3] Figure 3 is an explanatory diagram of the underground manhole facility. (Example 2) [Figure 4] Figure 4 is an explanatory diagram of the connector for the underground manhole facility. (Example 3) [Modes for carrying out the invention]

[0012] Underground manhole facilities refer to facilities that secure underground space for branching, connecting, and managing underground utilities such as underground water supply and drainage facilities including drainage manholes and water tanks, CAB facilities for telecommunications equipment, water supply facilities, and gas facilities, as well as underground boxes for cable entry, branching, connection, and management, and water pipes and gas pipes. Each facility must be able to withstand external forces such as soil pressure and groundwater pressure that it experiences underground, but the tolerance for water leakage and the degree of safety that must be ensured for the facility may differ.

[0013] The vertical panel, a component of the underground manhole facility of this invention, is a plate-like body having a ground side and an internal space side, and upper and lower surfaces and left and right sides, with other vertical panels adjacent to it on the left and right. Regarding the orientation of the vertical panel, the outer ground side is considered the front, and the internal space side is considered the back. Regarding left and right, the vertical panel has a contact surface with the adjacent vertical panel to its left and is connected by a connector. The same relationship exists with adjacent vertical panels on the right. Regarding top and bottom, the upper surface of the vertical panel may be fitted with anti-slip features between it and the lower surface of the vertical panel placed on top of it, but this is not essential as a structure if the external forces are uniformly distributed and uniformly directional, and may only be provided out of necessity for construction. In addition, from the viewpoint of preventing water leakage and intrusion, packing such as seals may be used between adjacent vertical panels.

[0014] The following example shows earth pressure as a typical external force related to a manhole facility underground. In this example, the underground manhole facility has five vertical panels installed in series. Earth pressure is generated perpendicular to the four front sides, with an magnitude proportional to the height from the ground surface. This is as shown in the cross-section diagram with a dashed line. When the external force is represented in a plan view at the same height, as shown in (3) External Force Diagram, the load is uniformly distributed and applied from all four sides. The diagram used for the earth pressure calculation focuses on the lowest vertical panel, with regard to the earth pressure in the direction of the arrow.

[0015]

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[0016] An example of an underground manhole in this invention is shown in the perspective view (1) of Equation 1. An external force acts on this manhole perpendicular to the outer wall, with earth pressure equal in magnitude to that of the horizontal plane, as shown in the external force diagram (3) of Equation 1. The vertical earth pressure distribution is shown in the cross-sectional view along the dashed line in the perspective view (1), as shown in (2). Since the magnitude of the load is proportional to its depth, the overall equation is P = 1 / 2 × γ × H, as shown in Equation 1. 2 ×tan 2The ratio is (45°-φ / 2), and the distributed load per unit length (in the notation of Equation 1, the unit height of the vertical panel) is q = γ × H' × tan(45°-φ / 2). The elements of the formula are as shown in Equation 1. If it is necessary to consider groundwater pressure, the external force can be determined by adding it to the earth pressure. In this example, as shown in H', the external force per unit length is calculated by the product of the earth pressure at the average position of one vertical panel height and the height of the vertical panel. However, in cases where the height of the vertical panel is large, it may be necessary to set the maximum external force. Next, we will explain the internal stress of the members of the underground manhole facility that is generated by this external force. However, although vertical stress and shear force require separate consideration, their influence is relatively small and will be omitted in this specification.

[0017]

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[0018] Equation 2 shows the change in shape and its cause in the absence of a connector in response to the external force shown in Equation 1. Equation 2(1) shows the arrangement of the vertical panels and the relationship between the adjacent vertical panels on the left and right. The horizontal member 1 is arranged so as to sandwich the vertical member 2, and the left and right rear ends of the vertical panels of member 1 are in contact with the left and right sides of the vertical panels of member 2, so that four contact surfaces are formed for the entire box. If there are no connectors, the vertical panel will deform by bending inward towards the internal space due to the external force load in Equation 1, as shown in Figure 2(2), and will open towards the front (ground side) at the contact surface as shown in the same figure. The main cause of this is the bending moment generated in the member due to the action of the external force. The bending moment acting on the vertical panel is at its maximum value at the center of each member, as shown in Equations 2(4) and (5), where M1 = q × L1 2 / 8, M2=q×L2 2 This is 8 / 8. This bending moment is such that a compressive force acts on the front side and a tensile force acts on the back side, with respect to the center line of the member cross-section shown in Figure 2(3). As a result, the deflection angle, which is the angle the member makes before the external force is applied, is maximized at the left and right ends of the vertical member, resulting in a gap opening on the front side at the contact surface.

[0019]

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[0020] Figure 3 shows the bending moment acting on the rigidly connected members at the corners of the box structure with an internal space in the external force state of Figure 1. Equation (0) in Figure 3 is the theoretical value of the bending moment when the beam structure of member ABCD receives equal distributed loads in a direction perpendicular to the outside, and is obtained from the literature shown in Figure 3. The bending moment has the tensile force generation direction on the internal space side of the member as the positive side. Also, the members in the horizontal and vertical directions have lengths L1 and L2, and the second moment of area is I1 and I2. The corner part is, on the drawing, the range surrounded by solid and broken lines at the four corners of the box structure, and is indicated as A OUT in the like display. Although external forces also act from the outside of the corner part, the influence on the bending moment is small, so it is omitted. For the members of the beam structure to be stable against external forces, as shown in the formula cited from the literature in Figure 3, the bearing strength against the negative bending moment generated at each corner is required. When the second moment of area of the vertical and horizontal members is the same, that is, I1 = I2, as shown in Figure 3(1), M A = M B = M C = M D = -q×L2 2 / 12×(1+(L1 / L2) 3 ) / (1+L1 / L2), and when further L2≧L1, Figure 3(2) holds, and M A = M B = M C = M D ≧ -q×L2 2 / 12. Adding L2 = L1 to the previous conditions, M A = M B = M C = M D = -q×L2 2 / 12. That is, it is the minimum value of the formula in Figure 3(2). In this invention, the connector serves to prevent the occurrence of voids at the joint surface of the vertical panels in the underground manhole facility. To prevent voids from occurring at the joint surface between member 1 and member 2 in Figure 2(2), the deflection angles at the left and right ends of member 1 and the angles on the left and right sides of member 2 are set to 0. The connector ensures strength against the bending moment generated at the corner obtained in Figure 3, thereby preventing the occurrence of voids between the members. When the vertical panels are made of concrete, the tensile stress due to the bending moment generated at the midpoint of the members (at position L1 / 2 for member 1 and L2 / 2 for member 2) requires separate consideration of reinforcement arrangement, etc., but this consideration is omitted in this specification.

[0021]

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[0022] The function of the connecting member, which consists of a connector and a connector receiving portion, is explained by Equation 4. The connecting member, by arranging the connector and the connector receiving portion that can withstand the tensile force applied to the connector, provides the end of member 1 L1 with the bending moment M shown in Figure (2) of Equation 4. P This generates a bending moment M of type 3. A This supports structural stability. That is, as shown in equation 4(1), M P ≦M A Therefore, the tensile force applied to the connector (acting as a compressive force on member 1) is P ≥ q × L 2 / (6×T) is required. On the other hand, for member 2, the bending moment on the side due to the external force is M as shown in Equation 3. A This M A The stress σ inside member 2 generated by X Regarding this, as shown in Figure 4 (1), at position X, σ X =M A This becomes / I² × X. X The maximum value (maximum tensile force) is σ at the position X = -T / 2 X=-T / 2 The compressive force σ acting on the contact surface due to the tensile force of the connector shown in Figure 4(2) is... PHowever, in order to prevent peeling stress from occurring, as shown in Equation 4 (2), P ≥ q × L 2 It must be / (2×T). Here, I=T is defined as the second moment of area per unit length. 3 We are substituting / 12. As a result, the minimum required tensile force is P = q × L 2 / (2×T) is obtained, and in this case, as shown in the resultant force diagram of Equation 4 (3) within the dashed line, no tensile force acts on the front side with respect to the resultant force at the end of the member. Considering the effect of external forces on member 1 and member 2, comparing Equations 4 (1) and (2), the tensile force P ≥ q × L applied to the connector 2 The condition / (2×T) is necessary.

[0023] In Equation 4, the connector is positioned at the midpoint of the width T, which is the center of the contact surface. However, the placement of the connector causes differences in the distributed stress on the contact surface. Equation 5 shows the effect of the connector's placement on the contact surface. A concentrated load is applied to a flat plate placed on a plane, and the reaction force from the plane below the plate is a linear distributed load, with a maximum value of a and a minimum value of b. The maximum peel stress generated on the front side of the contact surface due to the external force, as obtained in Figure (1) of Equation 4, is σ. X=-T / 2 This calculation assumes that force a is the tensile force a, and that force b acts on the contact surface by the connector, as shown in Figure 4(2) as an example, with a compressive force a acting on the front end and a force b acting on the back side.

[0024]

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[0025] Figure 1 of Equation 5 shows the reaction force from the plane to the underside of a flat plate when a concentrated load P is applied to the flat plate at an eccentric distance ε from the center toward the front (assuming a linearly distributed load). Equation 5(0) shows this, and from the equilibrium of forces, Equation 5(0-1) holds true, and from the equilibrium of moments, Equation 5(0-2) holds true. This clarifies the load distribution due to the eccentric position ε. As shown in Figure 4(2), when a load is applied to the center of the contact surface, it becomes a uniformly distributed load, which corresponds to the state ε=0 in Figure 52. The total load corresponding to the tensile force of the connector at this time is P=P shown in Equation 5(3). C Let's assume that = a × T. Below, we will show the magnitude of the required concentrated load, which changes depending on the location of the concentrated load. Figure 3 of Equation 5 shows the case where ε = -T / 6, and the minimum load b is 0 relative to the maximum load a. In this case, P -T / 6 As shown in equation (4), P -T / 6 =P C This results in 2 / 2, meaning the objective is achieved with half the magnitude compared to loading at the center. Similarly, the case of ε = -T / 4 is shown in Figure 4 and Equation (5) of Equation 5, and the case of ε = -T / 2 is shown in Figure 5 and Equation (6) of Equation 5. In the case of ε = -T / 4, it is 2 / 5, and in the case of ε = -T / 2, it is 1 / 4. When a connector is placed at these positions where ε < -T / 6, it is necessary to consider that peeling stress is acting on the back side when tensile force is applied to the connector and no external force from the ground side has yet acted. That is, it is necessary to note that b in Figures 4 and 5 of Equation 5 represents peeling stress. [Examples]

[0026] Figure 1 is an explanatory diagram of an underground manhole facility 1 having an internal space 21 that is approximately square in plan view and has two branches, as an embodiment of the present invention. Figure 1(1) is a perspective view, and the vertical panels 3 a, b, c, d, and e shown in the perspective view are shown in Figures 1(2), (3), (4), (5), and (6), respectively. Figure 1(2) shows the top surface 32, front surface 31, and left and right sides 34 and 33 of the vertical panel, while Figures 1(3) to (6) show the front surface, left side, and right side to represent the shape of the vertical panel. This underground manhole has an arrangement of vertical panels similar to that of Equation 2, and vertical panels b and d on the side with the branch section are provided with connector insertion parts 36 at the left and right ends to connect and fix them to the adjacent vertical panels on the left and right. Vertical panel a, which is connected to the left end of vertical panels b and d, is provided with connector receiving parts 37 on the left and right sides. In this example, the vertical panel opposite the illustrated vertical panel is the same shape, so its illustration has been omitted. Vertical panels can be used in two ways: as shown in a, they form the exterior wall as a single panel; or as shown in b, c, d, and e, they are stacked together in multiple panels.

[0027] Figure 2 shows details of the connecting member of Embodiment 1. Figure 2(1) shows the state before the contact surface 35 on the back of the end of one vertical panel and the contact surface 35 on the side of the adjacent other vertical panel come into contact. The bolt 41, which is the connecting device 4, is inserted into the connecting device insertion part 36 at the left end of one vertical panel, a washer 45 is placed on the seating surface, and by tightening and rotating the head portion, it is combined with the embedded nut 44, which is the connecting device receiving part 37 embedded on the right side of the other vertical panel, and a compressive force is applied to the two contact surfaces, fastening them together. Figure 2(2) illustrates how a bolt 43 is embedded in the right side of the other vertical panel as a connecting part receiving section, and is inserted into the connector insertion section at the left end of one vertical panel. The nut 42, which is threaded through the tip of the threaded part protruding from the front of the vertical panel, is tightened and rotated, applying compressive force to the two contact surfaces and thus fastening the connection. Furthermore, regarding the connection, as shown in Figure 1, there are cases where both the left and right sides are connected, as in vertical panels a, b, and d, and cases where only the left or right end is connected, as in vertical panels c and e adjacent to the left and right sides of the reinforced concrete rectangular culvert (hereinafter referred to as a box culvert) 22 installed as a branch. In this case, one-sided fixing assuming a cantilever beam is required. One-sided fixing assuming a cantilever beam will be explained by Equation 6.

[0028]

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[0029] Equation 6 shows the tensile force of the connector required when the vertical panels are connected on one side. The plan view in Figure 6(1) shows two types of connection methods for two vertical panels sandwiching a box culvert. The connection shown in Figure 6(3), a detailed view above, is the connection method for vertical panels c and e in Figure 1 of Example 1, with the rear end of the vertical panel being the contact surface. On the other hand, the connection shown in Figure 6(4), a detailed view below Figure 6(1), is a connection where the side of the vertical panel is the contact surface. Although the connection methods differ, in order to maintain the shape of the box, the intersection angle between the connecting plates must be kept at a right angle, and for that purpose, it must be in a cantilevered state as shown in Figure (2) of Equation 6. At the end, as shown in Equation (0) of Equation 6, M = q × L 2 A bending moment of 2 / 2 acts. In the case of the connection shown in Figure (3) of Equation 6, as shown in Equation (1) of Equation 6, P≧q×L 2 A connector with a tensile force of / T is required, but in the case of the connection shown in Figure (4) of Equation 6, P≧3×q×L 2 A connector of type / T is required. Compared to Figure 6(3), this connector has three times the strength, and in the case of single-sided connection, it is advantageous to have a connection surface at the back end of the vertical panel as shown in Figure 6(3). Note that for cantilevered vertical panels, shape fixation is assumed based on the connection status of the upper and lower vertical panels sandwiching the cantilevered type. Regarding the strength of the connector, the tensile strength P≧q×L shown in Equation 4 is used. 2 Although this value is larger compared to / (2×T), it must be noted that the length L of the vertical panel is different. [Examples]

[0030] Figure 3 shows an underground manhole facility 1 as an embodiment of the present invention, having a roughly square inner space 21 with two branches of circular concrete pipes 23. In this example, the vertical panel 3 has a connector insertion part at the left end and a connector receiving part on the right side, and the outer wall part 2 of the manhole facility has a tomoe-shaped arrangement of vertical panels.

[0031] Figures 3(2) and 3(3) are exploded views of the manhole facility shown in Figure 3(1). The four vertical panels enclosing the roughly square interior space on the plan are each composed of a single vertical panel. Figure 3(1) is a perspective view of the manhole facility, with the vertical panels 3 designated as a and b. The members opposite a and b are identical in shape and are omitted. Figure 3(2) shows the front view of vertical panel a in the center, with the left and right side views on the left and right. The rear view is a left-right inversion of the front view, and the plan view and bottom view have the same external shape and are both omitted. Multiple insertion holes, which are connecting parts 36, are arranged in a row at the left end of the front side, and multiple connecting receiving parts 37 are embedded in a row in the center of the right side. [Examples]

[0032] In Examples 1 and 2, the connector insertion portion 36 of the vertical panel 3 was shown as an example of an insertion hole, but in Figure 4, an example of a notched connector insertion portion 38 is shown. As explained using Equation 5, the effect of the connector 4 differs depending on its installation position. Against external forces from the ground side, in order to deal with peeling stress that generates a gap on the front side as shown in Equation 2, the vertical panel has an insertion portion cut out from the side, which can be aligned with the position of the connector receiving portion 37 installed on the side of the adjacent vertical panel to be connected. Furthermore, in order for the compressive force acting between the two vertical panels due to the tensile force applied to the connector to act as assumed in equation 5 at the contact surface, the compressive force must be distributed over the surface. To achieve this, it is conceivable that a load-distributing plate 49, such as a flat washer with a large contact area as shown in Figure 4(2), is used at the bolt head to be fastened, and a connector stress distribution area 48 as shown in Figure 4(1) is provided at the receiving end. [Examples]

[0033] The following figure 7 describes the structural characteristics when the external force from the internal cavity 21 of an underground manhole is dominant. This assumes a case where the water pressure inside a tank, such as an underground water tank, exceeds the external force from the ground. Figure 7(1) schematically shows the deformation of an underground manhole subjected to equal external forces from its interior without any connectors. Contrary to the state shown in Figure 2, the back sides of the four contact surfaces deform to open up. To prevent the deformation caused by the peeling stress on these contact surfaces, the connectors necessary can be assumed to be the bending moment generated at the corners of the rigid frame structure shown in Figure 3, acting as a uniformly distributed load acting from the inside of the rigid frame structure (the interior space side of the manhole facility). Regarding the eccentric position of the connectors for effective use, they should be placed on the back side, not the front side, from the center line shown in Figure 5. As shown in Figure 7(2), an example is shown where they are placed +ε on the back side from the installation center line. Furthermore, the stress distribution allowance for the connectors is also provided on the back side.

[0034]

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[0035] 1. Underground manhole 2 exterior wall section, 21 interior section, 22 box culvert section, 23 circular pipe section 3 Vertical panel, 31 Front view, 32 Top view, 33 Right side view, 34 Left side view, 35 Contact surface, 36 Connector insertion part, 37 Connector receiving part, 38 Notched connector insertion part, 39 Oval connector insertion part 4. Connector, 41. Bolt, 42. Nut, 43. Embedded bolt, 44. Embedded nut, 45. Washer, 46. Installation centerline, 47. Eccentricity distance, 48. Connector stress distribution allowance, 49. Load distribution plate

Claims

1. A manhole facility installed underground, having an outer wall section in contact with the ground and an inner space, The aforementioned exterior wall section is erected or stacked above, connected to the left or right, with the ground side as the front and the interior space side as the back, and includes vertical panels having left and right sides and top and bottom surfaces. It comprises a connecting device for connecting the vertical panel with another vertical panel adjacent to it on the left or right, The aforementioned vertical panel has a contact surface with the adjacent vertical panel on the back or left or right side of the left or right end, The contact surface on the back of the vertical panel is provided with a connector insertion portion that penetrates the vertical panel, or the contact surface on the left or right side of the vertical panel is provided with a connector receiving portion that engages with the end of the connector inserted into the connector insertion portion of the adjacent vertical panel. The aforementioned connector is a manhole facility that can apply compressive force to the outer wall portion by external force from the ground side or the inner space side, so as not to create a gap at the contact surface.

2. The manhole facility according to claim 1, wherein the external force from the ground side is dominant, and the contact surface is the side surface of the vertical panel, the connecting member receiving portion is provided on the front side by at least 1 / 6 of the distance between the front and back of the vertical panel (hereinafter referred to as the width of the vertical panel) from the center plane between the front and back of the vertical panel (hereinafter also referred to as the center line in a plan view of the upper surface of the vertical panel).

3. The manhole facility according to claim 1, wherein external forces from the internal space side are dominant, and the contact surface is the side surface of a vertical panel, the connecting device receiving portion is provided on the back side of the vertical panel at least 1 / 6 of the width of the vertical panel from the center line of the vertical panel in plan view.

4. A manhole facility according to claim 1, wherein the vertical panel is made of concrete.

5. A manhole facility in which the connector according to claim 1 is a screw fastening member that is a combination of male and female threads.

6. A vertical panel which is a component of the manhole facility according to claim 1.

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