Manhole Base Asymmetry and Flat Bottom Design
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Solution Overview
Problem
The existing manhole systems require costly and time-consuming excavation in confined spaces for installation, which disrupts traffic and increases construction time due to the need for a stable and level surface for the manhole base, especially in urban areas.
Innovation Solution
A manhole base design featuring a sealing, pluggable, or latchable connection with stiffening elements, a transition section, and an inner circular ring surface for enhanced stability and ease of installation, made from polymer materials like polypropylene for durability and cost-effectiveness, with reinforcement ribs for force distribution and easy cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a conventional manhole base is installed on a truncated cone or trapezoidal excavation pit to ensure stability, then the manhole base achieves stable installation, but the excavation process becomes costly and time-consuming, especially in confined urban spaces
Solution Approach 1:
The invention changes the geometric parameters of the manhole base by providing a substantially flat base surface instead of requiring a truncated cone or trapezoidal excavation pit. This parameter change allows installation on smaller, flatter subgrades, reducing excavation requirements while maintaining stability through the base's inherent design with reinforcement elements and rib structures
Solution Approach 2:
Instead of adapting the excavation pit shape to match traditional manhole base requirements (truncated cone or trapezoidal), the invention inverts the approach by designing the manhole base with a flat bottom that adapts to smaller, simpler excavation sites. This reversal of the adaptation direction enables installation in confined urban spaces without extensive excavation
2Ease of manufacture
If the manhole base is designed with a uniform cross-sectional area throughout, then manufacturing is simpler, but structural stability against lateral earth pressure is reduced
Solution Approach 1:
The invention applies asymmetry by designing the manhole base with different cross-sectional areas at different heights. The base portion has a smaller cross-sectional area than the upper portion, creating an asymmetric structure that provides enhanced stability against lateral earth pressure while maintaining manufacturing feasibility through rotational molding or similar processes
3Stability of the object's composition
If the transition section between upper and lower sections is made smooth and rounded, then structural integrity is improved, but cleaning and maintenance become more difficult due to dirt accumulation
Solution Approach 1:
The invention uses spheroidality by providing a rounded transition section between the upper and lower portions of the manhole base. This curved design maintains structural integrity and stress distribution while the specific geometry prevents dirt accumulation by creating a self-cleaning surface that facilitates easy maintenance
Data Source
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AI summary
The invention relates to a shaft lower part (1) for a shaft system of a system for receiving, conducting, and storing a fluid, comprising a sealing, pluggable, and/or latchable connection to a shaft central part and/or shaft upper part, comprising a first outer wall (3.4) with reinforcement elements (12) on which lateral flanks (12a) are formed, and comprising a second outer wall (3.5) with reinforcement elements (12'). The shaft lower part comprises a first portion (4) and a second portion (5), wherein the first portion (4) forms the upper portion when seen in the installed position, and the second portion (5) forms the lower portion, said first and second portion being connected to each other in an integral manner by means of a transition portion (6). The shaft lower part also comprises a support surface (7) for placing on a base (8), said support surface having the shape of a circular or annular circular surface or approximately the shape of a circular or circular ring surface. The shaft lower part is characterized in that the second portion (5) has a smaller cross-sectional area F5 with respect to the outer wall (3.5) than the cross-sectional area F4 of the first portion (4) with respect to the outer wall (3.4). The cross-sectional area is the area which is obtained when the portion (4, 5) of the shaft lower part (1) in the installed position is projected vertically onto a horizontal plane E that lies below the portion. An inner circular ring surface (13) is formed in the shaft lower part (1) approximately at the level of the transition portion (6) along the entire inner circumference (1a), and reinforcement elements (9) are formed on the transition portion (6).