Non-monotonic piezocone dissipation curves of backfills in a soil-bentonite slurry trench cutoff wall

In this work, we describe our approach and experiences bringing an instrumented soil-bentonite slurry trench cutoff wall into a modern IoT data collection and visualization pipeline. Soil-bentonite slurry trench cutoff walls have long been used to control ground water flow and contaminant transport. A Raspberry Pi computer on site periodically downloads the sensor data over a serial interface from an industrial datalogger and transmits the data wirelessly to a gateway computer located 1.3 km away using a reliable transmission protocol. The resulting time-series data is stored in a MongoDB database and data is visualized in real-time by a custom web application. The system has been in operation for over two years achieving 99.42% reliability and no data loss from the collection, transport, or storage of data. This project demonstrates the successful bridging of legacy scientific instrumentation with modern IoT technologies and approaches to gain timely web-based data visualization facilitating rapid data analysis without negatively impacting data integrity or reliability. The instrumentation system has proven extremely useful in understanding the changes in the stress state over time and could be deployed elsewhere as a means of on-demand slurry trench cutoff wall structural health monitoring for real-time stress detection linked to hydraulic conductivity or adapted for other infrastructure monitoring applications.

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Cone Penetration and Dilatometer Tests to Evaluate Stresses in a Soil-Bentonite Slurry Trench Cutoff Wall

IFCEE 2021 ◽

10.1061/9780784483411.032 ◽

2021 ◽

Author(s):

Jorge Romana-Giraldo ◽

Daniel Ruffing ◽

Timothy Guider ◽

Benjamin Summers

Keyword(s):

Cutoff Wall ◽

Cone Penetration ◽

Bentonite Slurry ◽

Slurry Trench

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Effect of Phosphate Dispersant Amendment on Workability of Ca-Bentonite Slurry for Slurry Trench Cutoff-Wall Construction

Indian Geotechnical Journal ◽

10.1007/s40098-016-0217-3 ◽

2017 ◽

Vol 47 (4) ◽

pp. 445-452 ◽

Cited By ~ 6

Author(s):

Yu-Ling Yang ◽

Yan-Jun. Du ◽

Krishna R. Reddy ◽

Ri-Dong Fan

Keyword(s):

Cutoff Wall ◽

Bentonite Slurry ◽

Slurry Trench ◽

Wall Construction

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Chemical Compatibility of Slurry Trench Cutoff Wall Backfills Comprised of SHMP-Amended Ca-Bentonites in Lead-Contaminated Solutions: Hydraulic Conductivity Assessment

Lecture Notes in Civil Engineering - Sustainable Environmental Geotechnics ◽

10.1007/978-3-030-51350-4_37 ◽

2020 ◽

pp. 365-371

Author(s):

Yu-Ling Yang ◽

Yan-Jun Du ◽

Krishna R. Reddy ◽

Ri-Dong Fan

Keyword(s):

Hydraulic Conductivity ◽

Chemical Compatibility ◽

Cutoff Wall ◽

Slurry Trench

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bentonite slurry trench

Dictionary Geotechnical Engineering/Wörterbuch GeoTechnik ◽

10.1007/978-3-642-41714-6_21439 ◽

2014 ◽

pp. 123-123

Keyword(s):

Bentonite Slurry ◽

Slurry Trench

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Laboratory test results on self-hardening grouts for flexible cutoffs

Canadian Geotechnical Journal ◽

10.1139/t84-016 ◽

1984 ◽

Vol 21 (1) ◽

pp. 185-191 ◽

Cited By ~ 4

Author(s):

Robert P. Chapuis ◽

J.-Jacques Paré ◽

André A. Loiselle

Keyword(s):

Experimental Program ◽

Test Results ◽

James Bay ◽

Cement Slurry ◽

Cutoff Wall ◽

Hydroelectric Project ◽

Solid States ◽

Bentonite Slurry ◽

Laboratory Test Results ◽

Cutoff Walls

The addition of cement to a bentonite slurry gives a complex material called self-hardening grout which slowly sets to become a clay-like solid. The properties of these mixes are highly dependent on the bentonite and the cement used. Most information available up to now comes from European countries where the technique has been developed. As very little information was available about such mixes in North America, an experimental program was initiated to study their applicability for cutoff walls of certain dams of the James Bay hydroelectric project. The present paper describes the characteristics of different mixes tested in their fluid and solid states. Keywords: bentonite, cement, slurry, cutoff wall.

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Parameters affecting the thickness of bentonite cake in cutoff wall construction: case study and physical modeling

Canadian Geotechnical Journal ◽

10.1139/t04-090 ◽

2005 ◽

Vol 42 (2) ◽

pp. 646-654 ◽

Cited By ~ 16

Author(s):

Abbas Soroush ◽

Mohammad Soroush

Keyword(s):

Physical Model ◽

Physical Model Test ◽

Test Results ◽

Cutoff Wall ◽

Bentonite Slurry ◽

Cutoff Walls ◽

Plastic Concrete ◽

Wall Construction ◽

Using Data

Concrete cutoff walls are usually constructed using a panel-by-panel technique in which primary panels are constructed with space between them and then secondary panels are constructed and inserted in the spaces. A small thickness of residual bentonite cake from the slurry used during excavation usually remains in the construction joints between adjacent primary and secondary panels. The thickness of such bentonite-filled joints should be minimized in terms of the performance of the cutoff wall in controlling seepage. This research experimentally evaluated the effects of a number of design and construction parameters on the thickness of the bentonite cake using data from a case study (the cutoff wall of Karkheh Dam). A physical model test was developed and a number of tests were conducted. The test results showed that parameters such as age of the primary panels, cement content of the slurry, quantity of additives in the slurry, and circulation versus noncirculation of the slurry are responsible for the thickness of the bentonite cake. The results are presented and analyzed.Key words: cutoff wall, plastic concrete, bentonite slurry, bentonite cake, physical model.

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