Matching Items (4)
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- All Subjects: Civil Engineering
- Genre: Masters Thesis
Description
Underground robots, or "burrowbots," have the potential to revolutionize undergroundexploration and study subterranean environments. The objective of this thesis is to
preliminary explore a turning mechanism in burrowbots inside granular media. Building
on the recent progress on bio-mimetic self-burrowing robots, specifically, inspirations were
taken from both biological and engineering solutions for general angular motion over a
single axis, inside granular media. The newly proposed robot draws turning inspiration
from hydraulic skeleton found in organisms like earthworm, incorporating a segmented
body with ball-socket joint connections that allow for greater flexibility and
maneuverability like in the human spine and, using the pivot-based turning mechanism
used in Tunnel Boring Machine. The focus of this thesis is on the bending and turning
aspects of the robot.
The design of the robot is described in detail, including the process used to assemble the
segments and ball joints and including the control mechanism to initiate turning. The
bending / turning capabilities of the robot are evaluated through physical testing in a
controlled environment. The robot's performance is assessed in glass bead with 2 mm
particle size. The results demonstrate that the robot's segmented design with the ball-socket
joint connections enable it to turn inside the particulate media. This ability makes it a
promising candidate for soil exploration tasks.
The thesis proposes an analytical framework for the amount of torque required to rotate an
elementary body (cylindrical rod) when compared to the segmented robot design, to
understand the relationship of torque and angle inside granular media.
In conclusion, this thesis initiates a preliminary study in the field of soil exploration through
the development of a robot with a unique design inspired by biology, exploring the
capabilities of an underground robot equipped with a turning mechanism that allows it to
change direction. The results demonstrate that the robot is able to turn inside the media
which can pave the way for future research and applications in the field of underground
robotics. (Keywords: preliminary, granular media, burrowbots, ball-joint connection, segmenteddesign)
ContributorsPai, Manthan Rajendra (Author) / Tao, Julian (Thesis advisor) / Khodadaditirkolaei, Hamed (Committee member) / Zapata, Claudia (Committee member) / Arizona State University (Publisher)
Created2023
Description
This study evaluates the use of plant-extracted silica solution as a bio-based grout material for improvement of granular soils. Although silicate grout is a very well-established and popular technique in the ground improvement market, efforts have been initiated to replace chemically-synthesized silicate grout with plant-extracted silica grout. This initiative will increase the level of sustainability and consequently improve the existing market acceptability. The silica-rich plant source used for extraction was rice husk, which is an abundantly produced agricultural waste. The extraction method includes acid-leaching, temperature-controlled rice husk ash production and the preparation of an aqueous sodium silicate solution from the ash through an alkaline leachate method. Silica ash was in amorphous form containing 95% of silica content which is suitable for soil treatment. Gelation time was controlled in the absence and presence of sand under different pH values. Bio-based silica grouting showed an improvement of the shear strength of the soil as well as the hydraulic conductivity reduction.
ContributorsSayed Mostafa, Ahmad (Author) / Zapata, Claudia (Thesis advisor) / Khodadaditirkolaei, Hamed (Thesis advisor) / Kavazanjian, Edward (Committee member) / Arizona State University (Publisher)
Created2019
Description
The California Department of Transportation (Caltrans) is required to comply
with the National Pollution Discharge Elimination (NPDES) permit, which includes the infiltration of stormwater runoff from highways and implementing soil based best managements practices (BMPs). Stormwater BMPs are in place to prevent pollution in stormwater runoff as well as to facilitate the stormwater discharge from the road. Per this new permit, Caltrans is to install soil based BMPs that can absorb the 85th percentile of a 24-hour stormwater event. In order to absorb the stormwater runoff, the area used is the Clear Recovery Zone (CRZ), which are the road embankments/slopes located adjacent to the roadside. The CRZ must be traversable and recoverable in order to meet roadside traffic safety standards. A major concern for Caltrans is the uncertainty on how these BMPs will affect the safety of a vehicle, if a vehicle were to interact with the soft soils.
In order to provide an insight on the effects of the BMPs, the modeling and simulation of vehicle dynamics under certain interactions between the roadside, soil, and vehicle was completed. The research used computer simulations to quantify the probability of rollover accidents under several different vehicle, driving and ground conditions. The vehicles traversing typical archetype roadsides on soft soil are simulated using MsMac3D software. It was important to model the properties of the vehicle, roadside, mechanical and hydraulic properties of soils realistically in order to obtain an accurate representation of a real-world vehicle and soil interaction.
The outcome was a library of simulations that provided quantifiable data on the effect that soft soils have on the safety and rollover potential of a vehicle traversing the CRZ.
with the National Pollution Discharge Elimination (NPDES) permit, which includes the infiltration of stormwater runoff from highways and implementing soil based best managements practices (BMPs). Stormwater BMPs are in place to prevent pollution in stormwater runoff as well as to facilitate the stormwater discharge from the road. Per this new permit, Caltrans is to install soil based BMPs that can absorb the 85th percentile of a 24-hour stormwater event. In order to absorb the stormwater runoff, the area used is the Clear Recovery Zone (CRZ), which are the road embankments/slopes located adjacent to the roadside. The CRZ must be traversable and recoverable in order to meet roadside traffic safety standards. A major concern for Caltrans is the uncertainty on how these BMPs will affect the safety of a vehicle, if a vehicle were to interact with the soft soils.
In order to provide an insight on the effects of the BMPs, the modeling and simulation of vehicle dynamics under certain interactions between the roadside, soil, and vehicle was completed. The research used computer simulations to quantify the probability of rollover accidents under several different vehicle, driving and ground conditions. The vehicles traversing typical archetype roadsides on soft soil are simulated using MsMac3D software. It was important to model the properties of the vehicle, roadside, mechanical and hydraulic properties of soils realistically in order to obtain an accurate representation of a real-world vehicle and soil interaction.
The outcome was a library of simulations that provided quantifiable data on the effect that soft soils have on the safety and rollover potential of a vehicle traversing the CRZ.
ContributorsPonce, Esai Jonathon (Author) / Neithalath, Narayanan (Thesis advisor) / Underwood, Shane (Committee member) / Khodadaditirkolaei, Hamed (Committee member) / Arizona State University (Publisher)
Created2019
Description
This document presents the assessment of the swelling behavior of expansive clay stabilized with bio-based silica gel and subjected to wetting and drying cycles. The expansive clay used in this research was obtained from Anthem, Arizona. Rice husk is a rich silica by-product of rice production with commercial uses and applications in the industry. Rice husk ash from two different sources -California (named ASU) and India- were subjected to chemical characterization. Fourier Transform Infra-red Spectroscopy was used to verify the functional groups of the gel formed. Results showed differences between the ashes from different sources and confirmed the presence of silica structure bonds. X-Ray Diffraction (XRF) results showed that the ASU ash contained more amorphous silica than the Indian ash.One dimensional swell and consolidation tests were performed to investigate the volume change behavior of the untreated and silica gel treated remoulded samples. The free swell of the clay decreased from 12.3% (untreated sample) to 7.2% (ASU sample) and 11.4% (Indian sample). The effect of the wet and dry cycles on the swelling and consolidation characteristics of the untreated clay demonstrated that the treatment is irreversible after three cycles. Swelling of clay treated with ASU ash was reduced after the first cycle, while that of the clay treated with Indian ash was reduced after three cycles. This was due to the gelation time difference between treatments. Scanning Electron Microscopy images showed that the structure of the untreated clay was discontinuous, flaky and without aggregations whereas particles in the treated samples were aggregated and new bonds were created, decreasing the surface area. The X-Ray Diffraction (XRF) results showed that the main mineral responsible for expansive behavior of the clay studied was illite. The d-spacing of the illite decreased from 4.47Å for the untreated clay to 3.33Å for the treated clay. This study demonstrates a promising technique for clay swelling reduction and a more sustainable solution than that available to current practicing engineering.
ContributorsBogere, Limon (Author) / Zapata, Claudia E (Thesis advisor) / Kavazanjian, Edward (Committee member) / Khodadaditirkolaei, Hamed (Committee member) / Arizona State University (Publisher)
Created2020