Foundation Design and Construction Challenges with Marsh Deposits in a High Seismic Risk Zone

Author(s):  
T. Ted Miyake

Driven piles are ideal for supporting structures over very soft ground, especially in high seismic risk zones. Challenges include achieving sufficient vertical and lateral load capacities within the constraints of pile spacing and geologic conditions. Through a unique case study, the authors will describe the process of site exploration, foundation selection, pile design, and installation of over 3,000 concrete piles in a small 4.5-acre (1.8 hectare) site (average of one pile per 65 square feet). A state-of-the-art, $180 million plant for biosolids processing, biogas management and energy recovery was sited in marshland next to an existing sewage treatment plant. The new construction included a 70-foot (21 m) tall building and three closely spaced, 90-foot (27 m) high, 65-foot (20 m) diameter, egg-shaped steel digester tanks. The site, classified as class “F”, was underlain by up to 45 feet (14 m) of highly compressible peat and organic clays, below which was a dense sand and gravel layer. The groundwater was very shallow and site-specific seismic hazard analyses were required. Particularly challenging was achieving the needed lateral resistance to seismic loads in the very weak clay and peat deposits. The project was instructive of the importance of adequate characterization of geologic conditions even in small sites; the necessary iterative collaboration process between geotechnical and structural engineers; and the value of a well-designed indicator pile program. The test pile program allowed for refining (shortening) the design pile lengths for considerable cost savings and reduced installation time. Of interest to the reader will be the surprising depth to refusal for some areas of the site, despite the test pile program.

2003 ◽  
Vol 47 (11) ◽  
pp. 31-36 ◽  
Author(s):  
B. Rosén ◽  
C. Huijbregsen

With tightening up of effluent discharge standards from wastewater treatment facilities, many plants are facing costly augmentations and in many cases completely new plants will have to be constructed. The ScanDeNi® process was developed in Sweden for increased nitrogen removal at the Västerås Sewage Treatment Plant (STP), 125,000 p.e. near Stockholm, and can be described as a modified contact stabilisation process with pre-denitrification and a selector stage for nitrification. The STP was upgraded at a cost of some 25 Mill. SEK (2.5 Mill. USD). It has been successfully in operation since 1998, exceeding all expectations. The process is showing the following major advantages.•25-35% less volume for the same Sludge Retention Time (SRT) and secondary sedimentation sludge load, compared to conventional pre-denitrification; or a 25-35% higher load can be applied within the same volume with the same removal efficiencies. • The selector mechanism appears to be not limited to the nitrifying bacteria alone. Other microorganisms appear to be responsible for the reduction of surface active matter from the return activated sludge (RAS), as well as in the reject stream from sludge dewatering, resulting in an increase in a-values of approximately 50%.•Due to the high a-values less aeration is required, resulting in significant operating cost savings.•‘Automatic’ creation of anaerobic conditions, enabling biological phosphorus removal. Whilst rarely a concern in warmer climates, BNR plants in cold climates in winter often lose their capacity to nitrify. The Västerås STP has consistently maintained excellent effluent quality even with effluent temperatures as low as 7°C, and at an SRT of some 7-9 days, proving the effectiveness of the nitrifier selector. The ScanDeNi® process could offer excellent effluent discharge standards (T-N < 10 mg/L, T-P <0.5 mg/L) in smaller tank volumes and at a significantly lower operating cost, compared to conventional pre-denitrification systems.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Maciej Walczak

Changes of microbial indices of water quality in the Vistula and Brda rivers as a result of sewage treatment plant operationThis paper reports the results of studies of microbiological changes in the water quality of the Vistula and Brda rivers after the opening of sewage treatment plants in Bydgoszcz. The study involved determining the microbiological parameters of water quality. Based on the results obtained, it was found that the quality of the water in both rivers had improved decidedly after the opening of the plants, although an increased number of individual groups of microorganisms was found at the treated sewage outlet from one of the plants.


2000 ◽  
Vol 36 (4) ◽  
pp. 161-171
Author(s):  
KENITSU KONNO ◽  
NAOKI ABE ◽  
YOSHIRO SATO ◽  
KOJI AKAMATSU ◽  
MAKOTO ABE ◽  
...  

2017 ◽  
Vol 1 (1) ◽  
pp. 46-55 ◽  
Author(s):  
Athar Hussain ◽  
Manjeeta Priyadarshi ◽  
Saif Said ◽  
Suraj Negi

Most of the industrial sewage effluents used for irrigation contains heavy metals which cause toxicity to crop plants as the soils are able to accumulate heavy metal for many years. The vegetables grown for the present study were irrigated with treated wastewater brought from a nearby full-scale sewage treatment plant at different compositions along with tap water as a control. The concentration levels of the Cd, Co, Cu, Mn and Zn in the soil were found to below the toxic limits as prescribed in literature. Daily Intake Metals (DIM) values suggest that the consumption of plants grown in treated wastewater and tap water is nearly free of risks, as the dietary intake limits of Cu, Fe, Zn and Mn. The Enrichment Factor for the treated wastewater irrigated soil was found in order Zn> Ni> Pb> Cr> Cu> Co> Mn> Cd. Thus, treated wastewater can be effectively used for irrigation. This will have twofold significant environmental advantages: (1) helpful to reduce the groundwater usage for irrigation and (2) helpful to reduce the stress on surface water resources.


1995 ◽  
Vol 30 (4) ◽  
pp. 565-592 ◽  
Author(s):  
A.F. Gemza

Abstract Severn Sound continues to exhibit signs of eutrophication despite initial identification of the problem in 1969 and the construction of several sewage treatment plants since then. In general, improvements in trophic state indicators have been marginal, suggesting that the sewage treatment plants have had limited success in controlling phosphorus concentrations. These discharges likely contributed to the increased total phosphorus levels and consequently the higher phytoplankton densities of the nearshore waters. Phytoplankton biovolumes were on average one order of magnitude higher than in the open waters of Lake Huron with mean summer biovolumes as high as 8.0 mm/L. Algal biovolumes were most dense in Penetang Bay, which experienced limited exchange with the main waters of the sound. No significant long-term trends were observed. Water clarity was declining significantly, however, at a rate of -0.60 to -0.78 m/year throughout the sound except in Sturgeon Bay. Total phosphorus levels were highly variable from year to year; however, concentrations from a 20-year perspective were declining in the open waters at a rate of 0.70 µg/L/year, but response was limited in nearshore areas. In Sturgeon Bay, mean annual euphotic zone total phosphorus as well as soluble reactive phosphorus levels declined by as much as 50% following the construction of a sewage treatment plant with tertiary treatment. Phytoplankton genera typical of eutrophic waters continued to dominate the algal assemblage but members indicative of mesotrophic conditions have become apparent in some areas of the sound.


1972 ◽  
Vol 7 (1) ◽  
pp. 13-20
Author(s):  
D.D.P. Cane ◽  
G.J. Farguhar

Abstract A case of filamentous activated sludge bulking was investigated at an extended aeration plant treating wastes from a highway service centre. The purpose of the study was to find an effective control measure for the bulking and, if possible, to determine the cause of the bulking condition. Experiments were conducted to determine the effects upon bulking of: (a) a controlled copper dosage to the mixed liquor, (b) variations in the organic loading rate, and (c) maintenance of high and low dissolved oxygen concentrations in the mixed liquor. The microorganism responsible for the bulking condition was tentatively identified as Sphaerotilus natans. Extensive growths of these bacteria occurred in the sludge when the mixed liquor dissolved oxygen concentration dropped below 0.5 mg/1. Such dissolved oxygen levels had frequently occurred at this plant due to the use of timed aeration cycles and the use of insufficient air supply during peak loading periods. Variations in organic loading rates were found to have no adverse effect on sludge settleability. When bulking was slight, the condition could be improved by increasing the dissolved oxygen level to 1.5 mg/1, or more. The rate at which the filamentous growths could be eliminated from a highly filamentous sludge by increased aeration was very slow, but could be greatly increased by the simultaneous feeding of copper to the mixed liquor at a dosage rate of 1.0 mg/1, based on the raw sewage flows.


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