Automated SPT Apparatus with Sensor-Based Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Standard penetration tests (SPT) face errors due to difficulties in accurately marking distance increments, counting hammer blows, and maintaining consistent drop height, which compromise the reliability and validity of test results.
Innovation Solution
A system comprising a hammer assembly with a lifting device, an elevator assembly, and sensors for precise positioning and velocity control, allowing for automated and consistent performance of SPTs, including Imperial and Metric unit selection, and data storage for remote access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual marking of distance increments with grease markers is used, then the operator can quickly mark the increments, but the accuracy and precision of the distance measurements deteriorate due to ground disturbance and coarse indication
Solution Approach 1:
The patent replaces manual mechanical marking with an automated optical/laser-based distance measurement system. The system uses a laser distance meter or optical encoder to automatically measure and record the positions of distance increments, eliminating the need for manual grease marker application and providing precise digital measurements without ground disturbance.
Solution Approach 2:
The patent introduces an intermediary automated measurement device (laser distance meter or optical encoder) between the operator and the sampling assembly. This intermediary automatically tracks and records the position of the sampling assembly at each distance increment, providing accurate measurements without requiring direct manual marking on the disturbed ground.
2Ease of operation
If manual counting of hammer blows is performed, then the operator can count blows in real-time, but the reliability of blow count data deteriorates due to interruptions, distractions, and human error
Solution Approach 1:
The patent replaces manual human counting with an automated sensor-based detection system. The system uses accelerometers, vibration sensors, or optical sensors mounted on the hammer or sampling assembly to automatically detect and count each hammer blow, eliminating human error, interruptions, and distractions while providing reliable digital recording of blow counts.
Solution Approach 2:
The patent implements a feedback system where sensors continuously monitor hammer blow events and automatically update the blow count record. The system provides real-time feedback on the number of blows delivered, ensuring accurate tracking without requiring operator attention or manual counting, and can alert operators to any anomalies in the blow sequence.
3Stability of the object's composition
If automated chain drive system is used to raise and drop hammer, then the consistency of hammer delivery is improved, but the accuracy of drop height control deteriorates if the raising height is not adjusted as sampler advances
Solution Approach 1:
The patent implements a dynamic adjustment system where the automated chain drive's raising height is automatically adjusted based on the real-time position of the sampling assembly. Sensors detect the sampler's depth and the control system dynamically modifies the hammer lift height to maintain a constant standard drop distance, ensuring both consistency and precision throughout the test.
Solution Approach 2:
The patent uses a feedback control loop where the position of the sampling assembly is continuously monitored by sensors, and this information is fed back to the chain drive control system. The system automatically adjusts the hammer raising height based on this feedback to maintain the precise standard drop height, ensuring both consistency and measurement accuracy.
4Productivity
If automated apparatus is used to raise and drop hammer, then the productivity of SPT testing is improved, but the device complexity increases due to additional sensors and control systems
Solution Approach 1:
The patent designs the automated system with multi-functional components that perform multiple tasks. For example, the same sensor system used for distance increment measurement also tracks sampling assembly position for drop height control, and the same control system manages both chain drive operation and data recording, reducing overall system complexity while maintaining high productivity.
Solution Approach 2:
The patent combines multiple functions into integrated subsystems. The positioning system, blow count sensors, distance measurement, and data recording are merged into a unified automated control platform, reducing the number of separate components and simplifying the overall device architecture while improving testing efficiency.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system for performing a standard penetration test, including a hammer assembly with a hammer and a hammer lifting device, an elevator assembly for raising and lowering the hammer assembly, a hammer sensor for sensing a position of the hammer within the hammer assembly, and an elevator sensor for sensing a position of the hammer assembly relative to the elevator assembly. A method for performing a standard penetration test, including positioning a hammer assembly at a hammer assembly ready position, sensing with an elevator sensor a reference position of a hammer assembly relative to the elevator assembly, sensing with a hammer sensor a zero position of a hammer, lifting the hammer with a hammer lifting device from the zero position to a drop position of the hammer, sensing with the hammer sensor the drop position, and dropping the hammer onto an anvil.