Pipe Ovalization Measurement for Lateral Earth Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for measuring lateral earth pressures around pipes in geotechnical engineering are complex and lack a simple, effective way to derive dimensionless stress values, particularly in the vicinity of boreholes.
Innovation Solution
A method and device that measure the inner diameter of a pipe in multiple transverse directions, calculating ovalization to derive pressure changes using sensors and an analytical solution based on elasticity theory, correcting for pipe inclination and bending effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional methods are used to measure lateral earth pressures, then measurement capability is provided, but device complexity and measurement difficulty increase
Solution Approach 1:
The patent replaces complex mechanical pressure sensing systems with a simplified geometric measurement approach. Instead of using multiple pressure sensors to directly measure lateral earth pressures, the invention uses sensors to measure the inner diameter of the pipe at different longitudinal positions and cross-sectional orientations. The lateral pressure is then derived from the ovalization (change in cross-sectional shape) of the pipe, substituting direct mechanical pressure measurement with geometric deformation measurement.
Solution Approach 2:
The pipe itself serves as an intermediary element between the earth pressures and the measurement sensors. Rather than placing sensors directly in contact with the earth material, the pipe deforms under lateral pressure, and this deformation is transmitted to the sensors measuring the inner diameter. The pipe acts as a mediator that converts complex three-dimensional earth pressure into measurable two-dimensional cross-sectional geometry changes.
2Measurement precision
If multiple sensors and complex calculations are used to derive stress values, then measurement accuracy improves, but ease of operation decreases
Solution Approach 1:
The invention changes the measured parameter from direct pressure (force per unit area) to geometric dimensions (inner diameter at various positions). By measuring the ovalization of the pipe cross-section through diameter measurements at different orientations and longitudinal positions, the complex stress state is transformed into a geometric parameter that can be measured more simply and calculated through established elasticity theory relationships.
3Ease of operation
If pipe deformation is measured to derive pressure, then measurement simplicity increases, but measurement precision may be affected by pipe inclination and bending
Solution Approach 1:
The measurement process is segmented into distinct operational phases: first measuring pipe inclination at each longitudinal position, then measuring cross-sectional ovalization, and finally correcting the pressure derivation calculations based on the recorded inclination data. This segmentation allows the complex factors of inclination and bending to be addressed systematically rather than simultaneously, improving both ease of operation and measurement precision.
Solution Approach 2:
The measurement system incorporates feedback by using the measured pipe inclination and ovalization data to correct and refine the lateral pressure calculations. The inclination measurements provide feedback on the pipe's orientation, which is then used to adjust the pressure derivation, ensuring accurate results even when the pipe is not perfectly vertical or experiences bending deformations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Provides a simpler and more accurate method for measuring lateral pressure changes along a pipe, allowing for the derivation of dimensionless stress values and back-calculating earth pressures acting on the pipe, enhancing geotechnical engineering practices.
Implementation Method 1
an analytical solution based on elasticity theory
Data Source
AI summary
A method for measuring pressure exerted by earth material includes: providing a pipe with a longitudinal bore defining an inner diameter, providing a device with sensors to sense said inner diameter, wherein the device is to be moved within the pipe along the longitudinal bore, while a measurement of the inner diameter is taken in a first transversal direction at one longitudinal position of the pipe. Then a measurement of the inner diameter in a second transversal direction at the predetermined longitudinal position is taken, wherein the second transversal direction is oriented differently to the first transversal direction. Finally, an ovalization of the pipe is derived at that predetermined longitudinal position of the pipe through subtracting a diameter value of the first transversal direction from a diameter value of the second transversal direction.