Modular access chamber

Abstract

The present invention relates to a modular access chamber (100) comprising: a riser (120); and a two-part base, which comprises an outer unit (150) and an inner unit (140), wherein the inner unit (140) is concentric with the outer unit (150) so as to form an outer-inner base assembly, forming a slot (141) between the outer lateral surface of the inner unit (140) and the inner lateral surface of the outer unit (150); wherein the riser (120) is configured to be sealably secured in the outer-inner base assembly by fitting one end (121) of the riser (120) into the slot (141) of the outer-inner base assembly.

Description

[0001] MODULAR ACCESS CAMERA

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a modular access chamber, commonly known as a manhole or inspection chamber, used in the interconnection of public sewer networks, being important access points for network maintenance, such as in the case of blockages.

[0004] BACKGROUND OF THE INVENTION

[0005] Manholes (MHs), or inspection wells (IHs), are products used to interconnect public sewer networks. Inspection wells are commonly installed up to 2.50m deep and, due to their conventional internal diameter of 0.40m to 0.60m, do not allow an authorized individual to enter them to perform maintenance on the sewer network, allowing only visual inspection of the well. In turn, manholes, having a larger conventional internal diameter of 0.80m to 1.50m, allow authorized personnel to enter to perform maintenance on the sewer network and can be installed at a greater depth, reaching 5m or more, depending on the project. These diameter and depth specifications may assume other values ​​depending on the regional standard.

[0006] Manholes (PVs) and sewer pipes (PIs) have a riser pipe, accessible from the surface through an inlet at surface level. PVs have a chimney attached to an upper end of the riser pipe, through which initial access is provided, while PIs only have the riser pipe. A lower end of the riser pipe is connected to a lower base, where inlet and outlet pipes of the sewer system are connected. For this, the riser pipe and the lower base have corresponding perforations so that the inlet and outlet pipes of the sewer system connect to the lower end of the riser pipe. The lower base directs, usually through channels, the flow of sewage from one or more inlet pipes to an outlet pipe. These inlet channels can adopt various configurations, with a flow angle varying between 0 o , 90° and 45° in relation to the outlet pipe.

[0007] Typically, manholes and sewer pipes are made of concrete. However, concrete is a material highly susceptible to strong chemical corrosion due to acids formed in sewage. This fragility increases the frequency of maintenance interventions for manholes and sewer pipes, in addition to reducing their lifespan. Concrete manholes usually do not have pre-drilled holes, so the user has greater freedom to choose where to connect the sewage pipes. However, when drilling the riser pipe for the connection of the sewage pipes, infiltration and exfiltration problems arise due to the use of mortar to seal the connections, as the mortar does not provide adequate watertightness.

[0008] Manholes (PVs) and risers can also be made of plastic material. These wells typically have specific pre-drilled points for connection to sewer pipes. This limits the use or requires the use of branch connections such as bends, reducers, etc., increasing the cost of the product and making maintenance more difficult. Existing plastic wells have an external structure with many protrusions. These protrusions were developed to give the parts better resistance to mechanical stress when the well is buried; however, these protrusions limit the installation of pipes in any region of the riser pipe.

[0009] Furthermore, the bases of PVs and Pis, when improperly dimensioned, do not perform well mechanically, suffering deformations when subjected to pressure. Additionally, their connection to the riser pipe requires additional parts and procedures, increasing the product's cost.

[0010] In W02005 / 024147, a PV / PI made of plastic material is disclosed, in which the riser tube and the base are connected by a cover enclosing both, fixed by a ring. This cover for fixing the parts adds complexity to the assembly and compromises the sealing of the unit. Different base configurations are provided, where the bases are divided into two parts with different channel configurations, allowing for various combinations between the parts. The base lacks means to achieve greater resistance against deformation, and opening connections in other regions of the riser tube outside the area indicated by the base is not permitted.

[0011] WO02066753A1 discloses a plastic PV / PI that supports the drilling of holes for piping in any region of the riser pipe. The base needs to be fixed to the riser pipe by welding, making its assembly more expensive and difficult, and it has mechanical reinforcements only on its sides, with a lower surface susceptible to deformation and thrust due to the action of the water table. The PV / PI disclosed in EP0924352A1 does not have a base with mechanical reinforcements to withstand external pressures, making it susceptible to deformation from internal and external loads. The fixing of the riser pipe to the base is done by fitting peripheral grooves on both parts along with filling these grooves with polyurethane, making its assembly more difficult and expensive.

[0012] The riser pipe of US5386669 has protrusions along its length, making it impossible to drill holes for piping in any area. Furthermore, the sides of its base are smooth, without any reinforcement, making the base susceptible to deformation and thrust due to the action of the water table.

[0013] EP1939369A1 also reveals a PV / PI made of plastic material, in which the riser pipe does not allow for connections in other regions and is connected to the base through a cover enclosing both, fixed by a ring, bringing additional complexity to its assembly and impairing the sealing of the assembly. The base is divided into four parts, allowing for different configurations, with a flow profile with rotational symmetry, without any type of mechanical reinforcement, making the base susceptible to deformation and thrust due to the action of the water table.

[0014] Therefore, the need for a chemically corrosion-resistant PV / PI (pipe / pipe) is evident, with a simple and effective connection between the riser pipe and the base, where the base has a reinforced construction to withstand external and internal loading, as well as resist thrust and erosion due to the action of the water table, and where the riser pipe allows for greater versatility by supporting holes for piping along its entire length.

[0015] DESCRIPTION OF THE INVENTION

[0016] A primary general objective of the present invention is to provide a modular inspection chamber that is simple to assemble, has good airtightness, and comprises a mechanically reinforced base, allowing for the installation of piping in any position around the contour of the riser pipe and at any height from the riser pipe, thus eliminating or at least reducing the limitations of currently known techniques.

[0017] A particular objective of the present invention is to provide a modular access chamber in which the riser tube is easily fixed to the base, without the use of extra equipment or materials, and which ensures adequate watertightness.

[0018] Another particular objective of the present invention is to provide a modular access chamber in which the base is divided between an internal unit and an external unit, with greater resistance to deformation and greater versatility of assembly.

[0019] Yet another particular objective of the present invention is to provide a modular access chamber equipped with means to prevent axial displacement between the internal and external units.

[0020] Another particular objective of the present invention is to provide a modular access chamber in which the base is resistant to thrust and erosion caused by the action of the water table.

[0021] Another particular objective of the present invention is to provide a modular access chamber in which the base allows for greater versatility in connecting the sewage piping and ensures proper flow without the use of conduits.

[0022] One or more of the aforementioned objectives of the present invention(s), among others, is / are achieved by means of a modular access chamber comprising: a riser tube; and a split base, comprising an external unit and an internal unit, wherein the internal unit is concentric to the external unit to form an external-internal base assembly, forming a groove between the external lateral surface of the internal unit and the internal lateral surface of the external unit; and wherein the riser tube is configured to be securely fixed to the external-internal base assembly by fitting one end of the riser tube into the groove of the external-internal base assembly.

[0023] One or more of the aforementioned objectives of the present invention, among others, is / are also achieved by means of a modular access chamber comprising: a riser tube; and a monolithic base, wherein the riser tube is configured to be securely fixed to the monolithic base by fitting one end of the riser tube into a groove in the monolithic base. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The objectives, technical effects, and advantages of the present invention will be apparent to those skilled in the art from the following detailed description, which refers to the accompanying figures, which illustrate exemplary, but not limiting, embodiments of the claimed objects:

[0025] Figure 1 shows an assembled modular access chamber 100, comprising a riser tube 120, a monolithic base 130 and a chimney 110, according to a first embodiment of the present invention;

[0026] Figure 2 shows a cross-sectional view of the connection between the riser tube 120 and the monolithic base 130;

[0027] Figure 3A shows a side view in section of the monolithic base 130;

[0028] Figure 3B shows a top view of the monolithic base 130;

[0029] Figure 3C shows a bottom view of the monolithic base 130;

[0030] - Figure 3D presents a perspective view of the monolithic base 130;

[0031] Figure 4 shows a detailed cross-sectional view of the connection between the riser tube 120 and the monolithic base 130;

[0032] Figure 5 shows an exploded view of a modular access chamber 100 with a split base, according to a second embodiment of the present invention;

[0033] Figure 6A shows a side view in section of internal unit 140 of the split base;

[0034] Figure 6B shows a top view of the internal unit 140 of the split base;

[0035] Figure 6C shows a bottom view of the internal unit 140 of the split base;

[0036] Figure 6D shows a perspective view of the internal unit 140 of the split base;

[0037] Figure 7A shows a side view in section of the external unit 150 of the split base;

[0038] Figure 7B shows a top view of the external unit 150 of the split base;

[0039] Figure 7C shows a bottom view of the external unit 150 of the split base;

[0040] Figure 7D shows a perspective view of the external unit 150 of the split base;

[0041] Figure 8 shows a detailed cross-sectional view of the connection between the 120 riser tube and the split base; and

[0042] Figure 9 shows a perspective view of a base with a flat, inclined upper surface, according to another embodiment of the present invention.

[0043] DESCRIPTION OF THE INVENTION'S EMPHASIS

[0044] Before any embodiments of the present invention are explained in detail, it should be understood that the invention is not limited in its application to the construction details and component arrangement demonstrated in the following description by references such as “in a preferred embodiment” and “in an alternative embodiment” or illustrated in the accompanying drawings. The invention may encompass other embodiments and be practiced or carried out in various ways, including combinations (even if not explicitly described) of features described in different embodiments. It should also be understood that the phraseology and terminology used in this descriptive report of the present invention are for descriptive purposes only and should not be considered limiting.

[0045] Thus, aspects of phrases such as “in a preferred embodiment” and “in alternative embodiments,” in various locations throughout this descriptive report, do not necessarily refer to the same embodiment of the invention presently claimed. Furthermore, particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments. All the various embodiments, aspects, and options disclosed herein may be combined in all variations, regardless of whether such features or elements are expressly combined in a specific embodiment description herein. This invention presently claimed is intended to be read holistically, so that any separable features or elements of the disclosed invention, in any of its various aspects and embodiments, are to be seen as intended to be combinable, unless the context clearly dictates otherwise.

[0046] DEFINITIONS The term “access chamber” 100 used herein shall be understood as a manhole or an inspection well, unless expressly indicated otherwise.

[0047] The term "tube" 120 refers to a tube with a preferably circular shape, but it can also adopt any polygonal shape, such as a hexagon.

[0048] The term “tube contour” 120 refers to the circumference of the riser tube when it is interpreted as having a circular shape, but also includes the perimeter of the riser tube when it is interpreted as having a polygonal shape.

[0049] The term “sealing element” 160 to 162 refers to a sealing ring, but is not limited to a circular shape and may encompass other shapes that cooperate with the tube 120 to ensure the tightness of the modular access chamber 100 when it assumes a polygonal shape.

[0050] The term “fastening elements” 157 refers to eyelets adapted for fixing and tensioning a tie rod, but also includes their equivalents such as hooks and the like.

[0051] MONOLITHIC BASE

[0052] In a first preferred embodiment, and as can be seen in Figures 1 and 2, the modular access chamber 100 comprises a riser tube 120 and a monolithic base 130, wherein the riser tube 120 is fixed directly to the monolithic base 130 by fitting one end 121 of the riser tube into a groove 131 in the monolithic base 130.

[0053] In any of the embodiments described herein, the 120 riser pipe is smooth and can be manufactured by rotomolding. Alternatively, and as visualized in Figure 5, the 120 riser pipe is corrugated and can be manufactured by extrusion, and both the 120 riser pipe and the monolithic base 130 or a split base, which will be described later, are preferably made of a plastic material, such as polyethylene, polypropylene, PVC, among others, to achieve greater resistance to chemical corrosion caused by sewage, wherein the base can be manufactured by plastic injection or another suitable method.

[0054] According to Figure 4, the attachment of the riser tube 120 to the monolithic base 130 is achieved by means of at least one sealing element 160 fitted to the end 121 of the riser tube within the groove 131 of the monolithic base 130. Preferably, the sealing element 160 is a rubber ring that ensures the tightness of the seal. In this embodiment, the end 121 of the riser tube 120 has corrugations that form ridges and valleys, in which the sealing element 160 is fixed in one or more of said valleys, which ensures high tightness, since the sealing element 160 exerts a force against the inner wall of the groove 131.

[0055] In any of the embodiments described herein, the riser tube 120 does not have predefined openings, and may support the drilling of holes in any region of its contour for the fitting of inlet or outlet tubes 105. The inlet or outlet tubes 105 are also fixed to the riser tube 120 by sealing elements 162, preferably rubber rings, as shown in figure 5.

[0056] According to Figure 3C, the lower surface of base 130 has first longitudinal ribs 133, intersected by a latitudinal rib for structural reinforcement. The structural reinforcement ribs 133 comprise a shape with ridges and valleys.

[0057] The rib 133's shape, characterized by crests and valleys, can adopt a sinusoidal wave shape, a square wave, a triangular wave, a sawtooth wave, among others. Due to this specific shape, these ribs 133 help in the settling of the base in the ground and generate better structural conditions, reducing stresses and ensuring less bending which, as a consequence, will reduce the deformations generated by external forces on their surfaces, such as thrust forces.

[0058] As visualized in the 3D figure, the lateral surface of base 130 has secondary ribs 134 for structural reinforcement. These secondary ribs are spaced longitudinally around the lateral surface of base 130 and are surrounded by a rib spaced latitudinally in relation to them. This latitudinally spaced rib gives the circumference a portal frame effect, structuring it and providing it with increased annular stiffness capable of supporting the stresses generated by the lateral fill and weight force, preventing collapse.

[0059] According to Figure 3A, base 130 comprises an internal volume 135 to accommodate a filling material according to the application requirements. The filling material for the internal volume 135 of base 130 is a material with a higher density than the plastic material of base 130, such as concrete, crushed stone dust, sand with cement, among others. Filling the internal volume 135 of base 130 with at least one of these materials results in greater stability of the modular access chamber 100 when installed underground, in addition to providing resistance against the thrust exerted by the water table, if present.

[0060] In one embodiment, as visualized in figure 3B, the upper surface of the base 130 has drainage channels 132 so that a liquid is directed from at least one inlet tube 105 to at least one outlet tube 105.

[0061] According to Figure 3B, the outline of the base 130 comprises at least one recessed surface 139, in any region, shaped to match the shape of the inlet or outlet pipes 105, so as to guide the user in cutting the hole in the riser pipe 120 and housing a sealing element 162 for the inlet or outlet pipes 105. The recessed surface 139 is adapted to be contiguous with the drainage channels 132 and has a lower height relative to the height of the drainage channels 132 on the upper surface of the base 130. The recessed surface 139 with the aforementioned height difference serves as a guide, support, or orientation for positioning a drilling template for drilling the riser pipe 120, preventing, for example, the hole from being misaligned with respect to the drainage channels 132 and creating a region for manipulating the process of installing the seal on the riser pipe 120.In other words, this difference in level between the recessed surface 139 and the drainage channels 132 advantageously allows the operator to easily identify the region where the drilling of the inlet or outlet pipes 105 should be carried out and, when making the hole, the operator stops the tool's advance by approaching or touching the region of the difference in level. Furthermore, this difference in level also allows, with the use of a drilling template, that the drilled hole be centered, consequently ensuring that the lower generatrix of the inlet or outlet pipes 105 are aligned with the lower generatrices of the drainage channels 132.

[0062] In this embodiment, the flat regions 173 of the upper surface of the base 130 that delimit the channels 132 have an appropriate angle to direct liquids and solids that may splash onto regions 173 into the channels 132, and to prevent the accumulation of liquids and solids in these regions 173, as visualized in the 3D figure. By keeping regions 173 free of liquids and solids, the operator entering the modular access chamber 100 can lean on these regions 173 with greater safety.

[0063] In an alternative embodiment, according to Figure 9, the upper surface of base 130 is a flat inclined surface 170, with an angle between 1 o and 5 o, with a positive slope end 171 and a negative slope end 172, such that a liquid is directed by gravity from at least one inlet tube 105, from the positive slope end 171, to at least one outlet tube 105, at the negative slope end 172. In this embodiment, the inlet tubes 105 can be advantageously installed in any region around the riser tube 120, near the positive slope end 171.

[0064] SPLIT BASE

[0065] In a second preferred embodiment, the modular access chamber 100 comprises a riser tube 120 and a split base, wherein the split base comprises an external unit 150 and an internal unit 140, as shown in Figure 5.

[0066] The inner unit 140 is concentric to the outer unit 150 to form an outer-inner base assembly, forming a groove 141 between the outer lateral surface of the inner unit 140 and the inner lateral surface of the outer unit 150, as shown in Figure 8. The fact that the base is advantageously divided allows for a distribution of resisting forces in the base system; that is, the inner unit 140, being independent of the outer unit 150, will experience the forces resulting from less aggressive internal actions, while the outer unit 150 will withstand the more aggressive external forces. This distribution of forces gives the inner unit 140 greater stability in terms of deformation, due to its independence.Furthermore, the split base also allows the user to combine the 150 outdoor unit with various versions of the 140 indoor unit, having different channel configurations, and to choose the configuration that best suits a specific application.

[0067] According to Figure 8, the riser tube 120 is fixed directly to the external-internal base assembly by fitting one end 121 of the riser tube into the groove 141 of the external-internal base assembly. In this embodiment, the end 121 of the riser tube has corrugations that form ridges and valleys, and the internal unit 140 comprises, on its external lateral surface, a recess 147 for housing a sealing element 161, which presses against the inner part of the end 121 of the riser tube. At least one other sealing element 160 is fitted into one or more of said valleys, at the end 121 of the riser tube within the groove 141 of the external-internal base assembly, pressing against the internal lateral surface of the external unit 150. This is how the riser tube 120 is fixed to the external-internal base assembly. Preferably, the sealing element 160 is a rubber ring, and the configuration described here ensures high tightness.

[0068] According to figure 7C, the lower surface of the external unit 150 has first ribs 153 that converge towards the center of the external unit 150, intersected by a circular rib, both for structural reinforcement.

[0069] The 153 ribs, in a stepped shape of concentric circles accompanied by radial bars, serve to structure the bottom, with the aim of reducing deformations resulting from thrust forces due to the water table.

[0070] As visualized in Figures 6D and 7D, the outer unit 150 and inner unit 140 comprise, along their respective outer lateral surfaces, second ribs 144 and 154 for structural reinforcement. These second ribs are spaced latitudinally around said outer lateral surfaces of the outer unit 150 and inner unit 140. Furthermore, as illustrated in Figure 6A, the inner unit 140 also comprises a plurality of internal reinforcements 145 that extend parallel to each other, below, and in contact with, its upper surface.

[0071] This configuration enables the aforementioned units to withstand deformations resulting from external pressures, whether from radial or axial loads, such as the weight force exerted by a person when leaning on the upper surface of the internal unit 140 to perform maintenance on the modular access chamber 100, external pressures exerted around the access chamber 100 by external agents, among others.

[0072] The external unit 150 comprises fastening elements 157 for attaching tie rods, as shown in Figure 7B. The tie rods are also attached to corresponding fastening elements 157 present on the riser tube 120, as shown in Figure 1. The fastening elements 157 serve as attachment points for cables used to anchor the system when subjected to stresses resulting from the water table, as well as, in a second function, to facilitate lifting in the case of transport or lowering into the trench.

[0073] In one embodiment, as shown in Figure 6B, the upper surface of the internal unit 140 comprises drainage channels 142 so that a liquid is directed from at least one inlet tube 105 to at least one outlet tube 105.

[0074] In this embodiment, the flat regions 173 of the upper surface of the internal unit 140 that delimit the channels 142 have an appropriate angle to direct liquids and solids that may splash onto regions 173 into the channels 142 and prevent the accumulation of liquids and solids in these regions 173, as visualized in figure 6D. By keeping regions 173 free of liquids and solids, the operator entering the modular access chamber 100 can lean on these regions 173 with greater safety.

[0075] According to figures 5, 6B and 7B, the external unit 150 and internal unit 140 each comprise at least one recessed surface 149 and 159 in any region of their contours, with a shape cooperating with the shape of the inlet or outlet pipes 105 so as to guide the user to make the hole cut in the riser pipe 120 and house a sealing element 162 for the inlet or outlet pipes 105. The recessed surfaces 149 and 159 being aligned with each other to be contiguous with the drainage channels 142 and having a lower height in relation to the height of the drainage channels 142 of the upper surface of the internal unit 140.The recessed surfaces 149 and 159, with the aforementioned height difference, serve as a guide, support, or orientation for positioning a drilling jig for drilling the riser pipe 120, preventing, for example, the hole from becoming misaligned with respect to the drainage channels 142 and creating a region for manipulating the sealing installation process on the riser pipe 120. In other words, this difference in level between the recessed surfaces 149, 459 and the drainage channels 142 advantageously allows the operator to easily identify the region where the drilling of the inlet or outlet pipes 105 should be performed and, when cutting the hole, the operator stops the tool's advance by approaching or touching the tool to the area of ​​difference in level.Furthermore, the aforementioned difference in level also allows, with the use of a drilling template, for the hole to be centered, consequently ensuring that the lower generatrix of the inlet or outlet pipes 105 are aligned with the lower generatrices of the drainage channels 142.

[0076] In an alternative embodiment, according to Figure 9, the upper surface of the internal unit 140 is a flat inclined surface 170, having a positive slope end 171 and a negative slope end 172, such that a liquid is directed by gravity, from at least one inlet tube 105, from the positive slope end 171, to at least one outlet tube 105, at the negative slope end 172. In this embodiment, the inlet tubes 105 can be advantageously installed in any region around the riser tube 120, near the positive slope end.

[0077] According to figures 6C and 7B, the internal unit 140 and the external unit 150 comprise respectively a recess 146 and a protrusion 156 cooperating with the recess 146, for fitting the internal unit 140 to the external unit 150.

[0078] The cooperative shape between recess 146 and protrusion 156 is such that it limits axial movement between the inner unit 140 and the outer unit 150, preventing the outer-inner base assembly from accidentally shifting from its intended position.

[0079] Another purpose of the recesses 146 and protrusions 156 is to prevent the user from incorrectly assembling the external-internal base assembly, ensuring that the internal unit 140 is always assembled with its part intended for the installation of the inlet and outlet piping 105 coinciding with the same inlet and outlet piping position 105 of the external unit 150.

[0080] In another embodiment, the internal unit 140 and the external unit 150 comprise respectively more than one recess 146 and more than one protrusion 156 cooperating with the more than one recess 146, for fitting the internal unit 140 to the external unit 150 in different positions as needed.

[0081] The external unit 150 also includes an internal auxiliary chamber 155, as shown in Figure 7A, to contribute to resistance to deformation when the system is under stress generated by the presence of groundwater.

[0082] Thus, it is concluded that the realizations and details of the system may vary considerably from what has been described and illustrated purely by way of non-limiting example, without departing from the scope of protection of the present invention as defined by the following claims. TABLE 1: LIST OF NUMERICAL REFERENCES

Claims

CLAIMS 1. MODULAR ACCESS CHAMBER (100), characterized by comprising: a riser tube (120); and a split base, comprising an external unit (150) and an internal unit (140), wherein the internal unit (140) is concentric to the external unit (150) to form an external-internal base assembly, forming a groove (141) between the external lateral surface of the internal unit (140) and the internal lateral surface of the external unit (150); and wherein the riser tube (120) is configured to be watertightly fixed to the external-internal base assembly by fitting one end (121) of the riser tube (120) into the groove (141) of the external-internal base assembly.

2. MODULAR ACCESS CHAMBER (100), according to claim 1, characterized in that the end (121) of the riser tube (120) has a corrugation that forms at least one crest and at least one valley, in which a sealing element (160) is fixed in at least one valley.

3. MODULAR ACCESS CHAMBER (100), according to any one of claims 1 to 2, characterized in that the internal unit (140) comprises on its external lateral surface a recess (147) for housing a sealing element (161).

4. MODULAR ACCESS CHAMBER (100), according to any one of claims 1 to 3, characterized in that the external unit (150) and internal unit (140) comprise, along their respective external lateral surfaces, structural reinforcement ribs (144, 154).

5. MODULAR ACCESS CHAMBER (100), according to any one of claims 1 to 4, characterized in that the external unit (150) and the lifting tube (120) comprise fastening elements (157) for attaching tie rods.

6. MODULAR ACCESS CHAMBER (100), according to any one of claims 1 to 5, characterized in that the outer (150) and inner (140) units each comprise at least one recessed surface (149, 159) in any region of their contours, wherein the recessed surfaces (149, 159) have a lower height relative to the height of the drainage channels. (142) of the upper surface of the internal unit (140).

7. MODULAR ACCESS CHAMBER (100), according to any one of claims 1 to 6, characterized in that the upper surface of the internal unit (140) is a flat inclined surface (170), having a positive inclined end (171) and a negative inclined end (172).

8. MODULAR ACCESS CHAMBER (100), according to any one of claims 1 to 7, characterized in that one of the internal unit (140) and the external unit (150) comprises at least one recess (146) and the other comprises at least one protrusion (156) cooperating with the recess (146), for fitting the internal unit (140) to the external unit (150).

9. MODULAR ACCESS CHAMBER (100), according to any one of claims 1 to 8, characterized in that the internal unit (140) comprises a plurality of internal reinforcements (145) below its upper surface.

10. MODULAR ACCESS CHAMBER (100), characterized by comprising: a riser tube (120); and a monolithic base (130), wherein the riser tube (120) is configured to be securely fixed to the monolithic base (130) by fitting one end (121) of the riser tube (120) into a groove (131) in the monolithic base (130).

11. MODULAR ACCESS CHAMBER (100), according to claim 10, characterized in that the end (121) of the riser tube (120) has a corrugation that forms at least one crest and at least one valley, in which a sealing element (160) is fixed in at least one valley.

12. MODULAR ACCESS CHAMBER (100), according to any one of claims 10 to 11, characterized in that the base (130) comprises, on its lower surface, first ribs (133) for structural reinforcement, wherein the structural reinforcement ribs (133) comprise a shape with crests and valleys.

13. MODULAR ACCESS CHAMBER (100), according to any one of claims 10 to 12, characterized in that the base (130) comprises, along its lateral surface, second structural reinforcement ribs (134).

14. MODULAR ACCESS CHAMBER (100), in accordance with Any one of claims 10 to 13, characterized in that the base (130) comprises at least one recessed surface (139) in any region of its contour, wherein the recessed surface (139) has a lower height relative to the height of the drainage channels (132) of the upper surface of the base (130).

15. MODULAR ACCESS CHAMBER (100), according to any one of claims 10 to 14, characterized in that the upper surface of the base (130) is a flat inclined surface (170), having a positive inclined end (171) and a negative inclined end (172).

Images