scholarly journals Investigation and mitigation of a failure at the Taxiarches canal of Mornos aqueduct

2013 ◽  
Vol 47 (4) ◽  
pp. 1792 ◽  
Author(s):  
N. D. Mourtzas ◽  
A. Gkiolas ◽  
D. Vakiris ◽  
V. Soulis
Keyword(s):  
Mechanical Properties ◽  
Water Supply ◽  
Water Discharge ◽  
Remedial Measures ◽  
Natural Slope ◽  
Clayey Material ◽  
Main Fracture ◽  
Water Outflow ◽  
Slide Area ◽  
Extensive Damage

The sudden soil fracture and failure at the Taxiarches canal of Mornos Aqueduct of the Athens Water Supply and Sewerage Company (EYDAP SA), took place approximately 540m after the exit of Elikonas tunnel and resulted in failure and displacement of the canal segments along an 80m long section. Due to the failure the water supply was interrupted and two extensive gullies, spaced 75m apart, were created by the water outflow. The water discharge resulted in subsoil erosion and transportation of vast masses of geomaterial and two of the canal segments downhill. The debris flow destroyed part of Prodromos-Saranti Road, swapping along olive cultivations and causing extensive damage to Saranti settlement. The failure of the canal occurred in an area of steep morphology, at the front of an overthrust, within tectonic breccia and calcareous-clayey material of chaotic structure and reduced mechanical properties, vulnerable to erosion. The boundaries of the main fracture were defined by the thrust geometry. Τhe study of permanent remedial measures included excavation of a cut in the natural slope on the uphill side of the failure, construction of a bypass pipe founded on bedrock and of an anchored pile wall with pre-stressed anchors on the downhill side of the new pipe, excavation and removal of the temporary fill and finally construction of a reinforced fill for rehabilitation of the slide area.

scholarly journals Asylum News

1899 ◽  
Vol 45 (191) ◽  
pp. 849-850
Keyword(s):  
Water Supply ◽  
Extensive Damage

Aberdeen Royal Asylum.— Extensive damage was caused by fire breaking out in the roof of the succursal asylum at Glack, which is some twenty miles from Aberdeen. About 100 patients are accommodated there, mostly of the quiet class, who are employed on the estate, which was acquired some ten years ago. Fortunately the water supply was ample, and, the safety of the patients having been secured, the lower storey was saved from destruction. The staff earned high commendation in having dealt so efficiently with the catastrophe. We trust that the chapter of accidents from fire in the Aberdeen Asylum is now closed. It has been most unfortunate of late years in this respect.

scholarly journals FAKTOR DOMINAN DAN STRATEGI PENYEDIAAN AIR BERSIH DI DESA RAWAN AIR BERSIH PADA KECAMATAN BAITUSSALAM KABUPATEN ACEH BESAR

2018 ◽  
Vol 1 (4) ◽  
pp. 903-914
Author(s):  
Erwin Ferdinansyah ◽  
Azmeri Azmeri ◽  
Eldina Fatimah
Keyword(s):  
Water Supply ◽  
Ground Water ◽  
Water Discharge ◽  
Water Source ◽  
Dominant Factor ◽  
Clean Water ◽  
Water Infrastructure ◽  
Service Areas ◽  
Drinking Water Supply System ◽  
Water Problems

Abstract: Baitussalam sub-district is one of the areas vulnerable to water in the district of Aceh Besar. During this time the District community Baitussalam it difficult to obtain a continuous flow of clean water. This is due to the remote location of the water source so as to obtain clean water, people need a lot of time and effort. Villagers District of Baitussalam were not served with clean water Regional Water Company (PDAM) Tirta Mountala, using ground water as clean water. Problems arise when the dry season, the ground water level has decreased, even loss of water discharge at all. This study aims to identify the dominant factors that may affect the distribution of water supply and analyze the strategy of water supply clean water prone villages in the subdistrict of Aceh Besar district Baitussalam. This research was conducted with questionnaires and interviews. Observations were made on the District community Baitussalam unserved water from PDAM Tirta Mountala. The results showed that the dominant factor affecting the distribution of clean water in District Baitussalam is an area that will be served by PDAM Tirta Mountala, and the allocation of increased funding water infrastructure. Strategy clean water supply in villages prone to water in the District Baitussalam is a set of service areas by PDAM Tirta Mountala towards building water treatment, then allocate increased funding water infrastructure, improve the discharge source of clean water related water needs in each village, and do development of Drinking Water Supply system (SPAM). Abstrak: Kecamatan Baitussalam merupakan salah satu kawasan rawan air bersih yang ada di Kabupaten Aceh Besar. Selama ini masyarakat Kecamatan Baitussalam mengalami kesulitan untuk mendapatkan air bersih yang kontinu mengalir. Hal ini disebabkan karena lokasi yang jauh dari sumber air sehingga untuk mendapatkan air bersih, masyarakat membutuhkan banyak waktu dan tenaga. Masyarakat desa Kecamatan Baitussalam yang tidak terlayani air bersih Perusahaan Daerah Air Minum (PDAM) Tirta Mountala, menggunakan air tanah sebagai air bersih. Permasalahan timbul saat musim kemarau, muka air tanah mengalami penurunan, bahkan kehilangan debit air sama sekali. Penelitian ini bertujuan untuk mengindentifikasi faktor dominan yang dapat mempengaruhi distribusi penyediaan air bersih dan menganalisis strategi penyediaan air bersih di desa rawan air bersih pada Kecamatan Baitussalam Kabupaten Aceh Besar. Penelitian ini dilakukan dengan penyebaran kuesioner dan wawancara. Pengamatan dilakukan pada masyarakat Kecamatan Baitussalam yang belum mendapatkan pelayanan air dari PDAM Tirta Mountala. Hasil penelitian menunjukkan bahwa faktor dominan yang mempengaruhi distribusi air bersih di Kecamatan Baitussalam adalah luas wilayah yang akan dilayani oleh PDAM Tirta Mountala, dan alokasi dana peningkatan prasarana air bersih. Strategi penyediaan air bersih di desa rawan air bersih pada Kecamatan Baitussalam adalah menetapkan wilayah pelayanan oleh PDAM Tirta Mountala terhadap bangunan pengolahan air bersih, kemudian mengalokasikan dana peningkatan prasarana air bersih, meningkatkan debit sumber air besih terkait kebutuhan air pada masing-masing desa, dan melakukan pengembangan Sistim Penyediaan Air Minum (SPAM).

scholarly journals TWO-POND FEEDING NURSERY FISH BREEDING COMPLEX

2020 ◽  
Author(s):  
Vl. N. Shkura ◽  
◽  
A. V. Shevchenko ◽  
Keyword(s):  
Water Supply ◽  
Water Discharge ◽  
Water Levels ◽  
Design Solution ◽  
Fish Ponds ◽  
Pipe System ◽  
Fish Trap ◽  
Fish Breeding ◽  
The Difference ◽  
Search Design

Purpose: development and description of the layout and design solution for a two-pond feeding nursery fish-breeding complex, which characterizes by compact placement of its constituent structures and their adaptation to the topographic conditions of the territory. Materials and methods. The theoretical and empirical basis for the development was made up of well-known recommendations on design and construction of pond complexes and survey data of operating fish-breeding facilities and their structures. During the development, the technologies of search design of engineering projects in compliance with fish breeding requirements and restrictions were used. Results. The fish-breeding complex includes: two fish-breeding ponds with a common dividing dam and a water supply system including a pumping station; water supply pipe system; a system of devices and structures that ensure the release of fish grown in ponds into a fish trap; spillway devices for discharging water from ponds and a fish trap with a set of regulating elements. Fish ponds are located on the floodplain lands of the river Don and are formed by protecting dikes. The bed of the reservoirs is planned with sections with longitudinal and transverse slopes to the water-fish collecting and-transporting ditches arranged in their bottom, allowing them to be emptied and the fish grown in the ponds to be directed to the outlet structures. The release of fish from the ponds is carried out by two tower water outlets. The design of the fish trap provides for the accumulation and seine fishing, it is equipped with means for regulating water discharge and maintaining conditions for fish. Conclusions. The developed layout and design solution for a two-pond fish-breeding complex with one fish trap is adapted to the local relief and the difference in water levels in ponds and in water intake. The implemented layout and design solutions can be used in the development of similar objects

SMHI Aqua: a new co-generated hydro-climate service to enable sustainable freshwater management

2020 ◽  
Author(s):  
Carolina Cantone ◽  
Helen Ivars Grape ◽  
Joel Dahné ◽  
Johan Andreasson ◽  
Mats Kindahl ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water Discharge ◽  
Water Levels ◽  
Water Withdrawal ◽  
Strong Impact ◽  
Seasonal Forecasts ◽  
Temporal Shift ◽  
Groundwater Availability ◽  
Climate Service

<p>Water management is strongly dependent both on the short-term and seasonal variability of weather patterns. The increase in evapotranspiration and temporal shift of snow melt due to temperature rise is expected to have strong impact on water resources in Sweden with risk of severe deficit in summer and surplus in winter. For drinking water producers and freshwater managers a good understanding of the current hydro-meteorological situation is essential to ensure both urban water supply and compliance of water regulations.</p><p>This study is the result of collaboration between SMHI and Nodra, the municipal water company in Norrköping, Sweden. In 2016, warmer temperatures and reduced precipitation rates led to very low water levels in a ground water treatment plant used to supply drinking water to Kolmården, a region highly influenced by tourism in the summer season. This raised the need of monitoring freshwater availability and hydrological seasonal forecasts to be implemented for ensuring optimal water usage. To this end, a hydrological model is setup to simulate the water balance in freshwater reservoirs for evaluating groundwater recharge in the soil. Short to medium range (1-10 days) weather forecasts and seasonal climatological forecasts (6 months ahead) of water levels are produced at the local scale. Aiming at supporting long-term water planning, different management strategies of water withdrawal are used to feed the operational forecasting systems to assess groundwater availability in the following months.</p><p>Within the framework of the Horizon 2020 CLARA project; SMHI co-developed Aqua, a water supply assessment service tailored to the needs of public authorities and private companies involved in the water supply sector. Aqua includes a web-based platform that incorporates real-time station observations of precipitation, temperature, water levels, water discharge and raw water withdrawal.  Forecasts of relevant hydro-meteorological modelled parameters are also included and presented in an intuitive way through maps, graphs and tables. To overcome the challenges of communicating results of the probabilistic component of hydrological seasonal forecasts to the users, the visualization of forecasted groundwater levels is kept simple, whilst the provision of historical values allows an easy comparison against normal conditions.</p><p>The availability of tools displaying observations, modelled results and forecasts facilitates the understanding of the current hydro-meteorological situations as well as future wet/dry periods also to non-expert users, increasing preparedness of public and private organizations to extreme conditions while ensuring water security. Operational since March 2019, the Aqua service has provided Nodra with valuable insights for planning of groundwater withdrawal and decision support for coping with water scarcity, showing the potential of the co-generated hydro-climate service to bridge the gap between operational management and scientific innovation.</p>

Microstructure and Properties of Al2O3-ZrO2 Ceramics Prepared by Microwave Sintering

2014 ◽  
Vol 633 ◽  
pp. 193-197 ◽  
Author(s):  
Yun Long Ai ◽  
Xiang Hua Xie ◽  
Wen He ◽  
Bing Liang Liang ◽  
Wei Hua Chen
Keyword(s):  
Mechanical Properties ◽  
Intergranular Fracture ◽  
Fracture Mode ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Transgranular Fracture ◽  
Submicron Scale ◽  
Main Fracture ◽  
Sintering Processes

ZrO2 doped with 7.5% (volume percent) nanoalumina ceramics were prepared by microwave sintering processes. The effects of nanoalumina additions and various sintering temperature on densification, phase composition, microstructure and mechanical properties of Al2O3-ZrO2 ceramics were investigated. The results show that the m-ZrO2 phase transformed into t-ZrO2 during the process of microwave sintering. Relative densities between 95% and 99% were attained in the different conditions. In any cases the grain size was maintained at a submicron scale at a processing microwave sintering. The presence of Al2O3 grains had an effect of hindering grain growth of ZrO2 grains. When the microwave sintering temperature was 1500°C, 7.5Al2O3-ZrO2 composite ceramics presented excellent mechanical properties: HV=12.0 GPa, σf=715.7 Mpa, KIC=11.9 MPa·m1/2. Compared with that of pure ZrO2 ceramic, the bending strength and the fracture toughness were improved 45% and 23% at least, respectively. The fracture mode was associated with sintering temperature: when the sintering temperature was 1350°C~1450°C, the intergranular fracture and transgranular fracture coexisted; when the sintering temperature was 1500°C, intergranular fracture was the main fracture mode.

Mechanical Properties and Microstructure of Boron Carbide-Cerium Boride Composite

2012 ◽  
Vol 482-484 ◽  
pp. 1551-1555
Author(s):  
Ke Wu Peng ◽  
Nian Wen Pu ◽  
He Li Ma ◽  
Ren Chen ◽  
Yan Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Boron Carbide ◽  
Fracture Mode ◽  
Main Fracture ◽  
Sintering Method

The mechanical properties of B4C-CeB6 composite prepared by hot pressed sintering method were tested. The study shows: the hardness of B4C-CeB6 composite increases with the content of cerium boride. When the content of the cerium boride is 4wt%, the hardness reaches its supreme value of 31.98Gpa，its hardness is improved nearly 21.09% compared to monolithic boron carbide. The content of the cerium boride does not affect greatly on flexibility strength. However，it gives much effect on fracture toughness. When the content of the cerium boride is 4wt%, the fracture toughness reaches its supreme value of 5.06MPa.m1/2, which is improved nearly 37.5% compared to monolithic boron carbide materials. The main fracture way of B4C-CeB6 composite is intercrystalline rupture, while the transcrystalline rupture is minor. It appears that this change of fracture mode gives rise to the improvement of the fracture toughness.

scholarly journals Salt intrusion in the Pungue estuary, Mozambique: effect of sand banks as a natural temporary salt intrusion barrier

2008 ◽  
Vol 5 (4) ◽  
pp. 2523-2542 ◽  
Author(s):  
S. Graas ◽  
H. H. G. Savenije
Keyword(s):  
Water Supply ◽  
Water Intake ◽  
Salt Water ◽  
Water Discharge ◽  
Dry Season ◽  
Salt Water Intrusion ◽  
Salt Intrusion ◽  
Water Intrusion ◽  
Salinity Levels ◽  
Monthly Discharge

Abstract. This paper presents a salt intrusion model for the Pungue estuary with the aim to determine the minimum discharge required to prevent the salt intrusion from reaching the water intake situated 82 km from the estuary mouth. The Pungue river is shared between Zimbabwe and Mozambique and has a large variation in precipitation and runoff. The mean monthly discharge can be as low as 8 m3/s and as high as 893 m3/s. The second largest city of Mozambique, Beira, relies on the Pungue for its water supply. In the dry season it frequently occurs that the water intake has to be ceased because the salinity of the Pungue is too high. The salt intrusion model used in this paper is based on a fully analytical and predictive theory which is confronted with measurements of salt intrusion and estuary topography. The paper presents the collection of estuary characteristics and the salt water intrusion measurements that were obtained by field measurements in 1993 and 2002. Using these data the salt intrusion model has successfully been applied. During salinity intrusion measurements in the dry season of 1993 it was observed that sand banks in the middle zone of the estuary prevented the salt water from intruding further upstream, resulting in lower salinity levels upstream than the theoretical salt water intrusion model predicts. This effect occurs during ebb of neap and average tides and can reduce the salt water intrusion by 10 km. The model indicates that in a natural situation a minimum monthly discharge of 12 m3/s is required to maintain acceptable salinity levels during high water and spring tide near the water intake. The actual water discharge upstream of the water intake has to be higher, since this minimum discharge does not take into account the water abstracted for irrigation and/or urban water supply. Current water abstractions lead to salt water intrusion near the water intake at approximately 10% of the time. The model indicates that an additional water abstraction of 5 m3/s will lead to an increase in salt water reaching the intake at 10% of the time. During neap tide the sand banks act as a temporary natural salt intrusion barrier reducing the chance of salt water reaching the water intake.

Experiment on Making Autoclaved Sludge Bricks with the Dewatered Sludge from Water-Supply Plant

2011 ◽  
Vol 261-263 ◽  
pp. 829-833
Author(s):  
Sai Jun Zhou ◽  
Jun Tong Qu
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Water Supply ◽  
Urban Water ◽  
Urban Water Supply ◽  
Optimal Parameters ◽  
Optimal Process ◽  
Curing Conditions ◽  
Urgent Task ◽  
Curing Condition

How to efficiently dispose of the urban water-supply plant sludge has become an urgent task of controlling pollution caused by municipal solid waste. This paper is an experiment on autoclaved sludge brick, which is mainly made of sludge from the water-supply plants, fly ash, lime, sand and cement, integrated with the manufacturing process of autoclaved fly ash brick. By orthogonal optimal process, we get the optimal parameters for making sludge bricks as follows: W sludge : W ash : W lime = 15%: 45%: 15%, stirring intensity being 1400r/min, forming and curing condition being the constant temperature and humidity Curing Box (60 °C, humidity 95%), and autoclave curing condition being 1.2Mpa (time 10h). With the optimal parameters, the compressive strength of the produced bricks reaches 20.8Mpa, and its flexural strength reaches 5.4 Mpa. Besides, stirring conditions, forming and curing conditions together with the influence of curing conditions on autoclaved sludge bricks’ mechanical properties are discussed.

Glacier sliding set by self-regulating feedback between friction and drainage efficiency

2020 ◽  
Author(s):  
Adrien Gilbert ◽  
Florent Gimbert ◽  
Kjetil Thøgersen ◽  
Thomas Schuler ◽  
Andreas Kääb
Keyword(s):  
Climate Change ◽  
Water Supply ◽  
Numerical Models ◽  
Water Pressure ◽  
Water Discharge ◽  
Coupled System ◽  
Dynamical Response ◽  
Main Process ◽  
Friction Laws ◽  
Basal Sliding

<p>Glacier basal sliding accommodates most of glacier motion and is the main process behind glacier dynamic variability, able to substantially modulate glacier response to climate change. In particular, it controls glacier instabilities, surges, ice stream development and flow speeds of most glaciers on Earth. Paradoxically, glacier sliding remains one of the least understood processes in glacier physics due to the difficulty of accessing and observing the sub-glacial environment. In numerical models, sliding of glaciers is traditionally determined by friction laws interlinking basal shear stress, sliding velocity and water pressure. However, assessing the effects of water pressure on sliding remains a challenge due to the sparsity of appropriate data to validate coupled ice-flow/subglacial-hydrology models. We unify here the description of subglacial cavities transient dynamic for basal friction and sub-glacial hydrology and show how it interacts as a self-regulating coupled system. Our results are in striking agreement with observation from a unique multi-decadal record of basal sliding and water discharge in Argentière Glacier (French Alps). We show that sliding speed of hard-bedded glaciers is set by the drainage efficiency necessary to accommodate the melt water supply rather than being driven by water pressure. We suggest that liquid water supply at the glacier base rather water pressure should be used to develop friction laws that include the effect subglacial hydrology. This will make glacier dynamical response to climate change more predictable.</p>

Debris flows and debris torrents in the Southern Canadian Cordillera

1985 ◽  
Vol 22 (1) ◽  
pp. 44-68 ◽  
Author(s):  
D. F. VanDine
Keyword(s):  
British Columbia ◽  
Debris Flows ◽  
Water Discharge ◽  
Warning System ◽  
Canadian Cordillera ◽  
Remedial Measures ◽  
Triggering Mechanism ◽  
Rock Fragments ◽  
Mitigation Methods ◽  
The Impact

In Canada, debris torrents (also referred to as channelized debris flows) occur in parts of British Columbia, Alberta, and the Yukon. At least 17 deaths and an estimated $100 million of damage to bridges and property can be attributed to this natural hazard. The debris mainly comprises large boulders, rock fragments, gravel- to clay-sized material, tree and wood mulch—materials that accumulate in the mountain creeks. To be susceptible to a debris torrent, a creek must have a drainage area within a critical range, a profile that is sufficiently steep, an accumulation of debris, and some form of triggering mechanism. The most common triggering mechanism is an extreme water discharge, which may result from a very intense rainfall or a temporary damming of the creek. In western Canada, the resulting torrents involve masses of debris, typically less than 50 000 m3, that travel down creeks at speeds between 3 and 12 m/s.Several passive and active forms of mitigation can be used to reduce the impact of debris torrents on creek crossings and neighbouring residents. Passive mitigation methods include avoidance of the area, relocation of structures and facilities, land use restrictions, and some form of warning system. Active mitigation methods include remedial measures to remove or counter the causes, and various forms of designed protection. Constructing check dams near the headwaters of the creek and stabilizing the valley slopes that border the creeks are examples of remedial measures. Constructing debris barriers or clear span bridges with adequate clearance are examples of designed protection.Howe Sound, north of Vancouver, British Columbia, has had a relatively high number of debris torrents. Recently, several major studies have addressed the extent of the hazard and recommended mitigative measures for this area. Many of the examples presented in this paper are drawn from this case history. Key words: debris flows, debris torrents, slope stability, Southern Canadian Cordillera, Howe Sound, geological process, design considerations.

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