The paper describes the automation and calibration of a hydraulic Rowe consolidation cell that tests 151-mm-diameter by 60-mm-high specimens. The associated measurement instrumentation for the cell and specimen preparation procedures are also described. The cell was used to perform a set of one-dimensional constant rate of strain (CRS) tests at two vertical strain rates, 0.1 and 1%/h. The nonlinear CRS theory of Wissa et al. (1971) is presented, including methods for interpreting test results at higher strain rates. The results from the Rowe cell tests conducted on resedimented Boston Blue Clay are compared to those from more conventional incremental loading (IL) oedometer tests (63.5-mm-diameter by 23-mm-high specimens). For both the 0.1%/h tests (in which negligible excess pore pressure was generated at the undrained specimen base) and the 1%/h tests, the compression curves compare well with the baseline IL oedometer test curves. Values of preconsolidation pressure, s´p, averaged 94.0 kPa in the Rowe tests and 94.5 kPa in the IL oedometer tests. The compression ratios, CR = ?ev/? log s´v, in the virgin compression range were slightly lower in the Rowe cell tests (average 0.156 versus an average CR = 0.173 in the IL oedometer tests), which may be due to different testing conditions (e.g., back pressure in the Rowe cell) or the larger Rowe cell specimen. The coefficient of consolidation and hydraulic conductivity values computed from the Rowe cell tests are essentially identical with regard to stress level to the IL oedometer tests. The automated Rowe cell data indicate that the device offers a reliable and potentially rapid method for determining consolidation parameters, including hydraulic conductivity.
Brackish groundwater desalination on the rise
Brackish water is water that is more saline than fresh. It’s not quite as saline as seawater, but it’s still too salty to be used without treatment. Typically, advanced treatment technologies — reverse osmosis and ultrafiltration, as well as other membrane-based technologies — are needed to purify and desalinate brackish groundwater before its use.Brackish groundwater can be directly used as cooling water for power generation, in aquaculture, and for drilling and hydraulic fracturing in...
Case study - Florida, USA – advanced sequencing batch reactor
300,000 gpd ASBR facility replaced the existing concrete and steel conventional extended aeration activated sludge treatment, settlement clarifiers, and aerobic sludge digestors. Receives wastewater collected from 14 neighborhoods, residential housing, nursing homes and hospital facilities on a 425 acre site. Wastewater treatment comprises flow metering, fine screening and washing, grit collection, surge tank (flow balancing), flow splitting, two (2) basin ASBR process, flow equalization, tertiary filtration...
Case study - Industrial ASBR wastewater treatment facility, India
This two (2) basin ASBR facility near Mumbai, receives a variety of industrial wastewaters collected from many factories and chemical production facilities.The 10,000 m3/d wastewater plant comprises flow metering, chemical treatment, pH correction, flow splitting, flow equalization with aeration, chemical precipitation and lamella plate clarification, two (2) basin ASBR biological treatment process, and effluent equalization. Waste sludge storage, conditioning and belt press facilities are provided. and the...
Fractured Bedrock Remediation - Case Study
ABSTRACT BOS 200® successfully remediates petroleum groundwater impacts in fractured bedrock at a former truck stop. Based on the post-injection groundwater results from the pilot test and full-scale injection, a No Further Action letter was issued in February 2015. CHALLENGES Over a period of 20 years, site investigation activities revealed a 320 foot (ft) long dissolved hydrocarbon plume within the fractured bedrock. Light non-aqueous phase liquid (LNAPL) was identified in one monitoring well and benzene...
Valtra and Kesla are a perfect combination for forestry work
Valtra and Kesla are an ideal pairing for forest tasks. Customers have used Valtra-Kesla combinations for years, of course, but now the two companies are also teaming up in product development and the sales network. For example, in Finland and some other markets Valtra and Kesla products can be purchased from the same dealer. The Unlimited Studio at the Valtra factory in Suolahti has also specialised in fitting Kesla forest equipment. Forest contractors Kyösti Tiainen and Heikki Pulkkinen from Punkaharju in...