L'utilisation de matériaux naturels pour la construction du barrage OA-5 sur la rivière Opinaca

1983 ◽  
Vol 10 (4) ◽  
pp. 614-626
Author(s):  
Michel Massiéra ◽  
Claude Pelchat

The OA-5 Dam is one of the earth structures of the EOL (Eastman–Opinaca–La Grande) project within the 'La Grande' hydro-electric complex at James Bay, Quebec. Three rivers were diverted to the La Grande River to increase the hydro-electrical potential of the LG-2 power plant. Dam OA-5 (32.3 m high and 385.6 m long) has a zoned section with an impervious central core, and rests on bedrock.The paper describes the different construction phases of the dam, i.e., Opinaca River diversion and closure, foundation treatments, earth and rockfill placement, quality control of materials, and the behaviour of the dam during and after filling of the reservoir. Keywords: closure, compaction, construction, dam, diversion, earth and rockfill, glacial till, grain size analysis, gravel, river, sand.

1985 ◽  
Vol 12 (4) ◽  
pp. 838-848
Author(s):  
Michel Massiéra ◽  
Claude Pelchat

The OA-10B dam is one of the earth structures of the EOL (Eastmain – Opinaca – La Grande) project within the "La Grande" hydroelectric complex at James Bay, in the northwest of Quebec. Three rivers, the Eastmain, Petit Opinaca, and Opinaca, were diverted to the La Grande River to increase the hydropotential of the LG-2 power plant. Dam OA-10B, 25 m high, has a zoned section with an impervious moraine central core, and rests mainly on overburden foundations consisting of heterogeneous deposits of glacial till. The paper describes the different construction phases of the dam with emphasis on foundation treatments. Key words: construction, core trench, dam, dewatering, excavation, foundation, glacial till, instrumentation, moraine, treatment.


Overburden is the unutilized rock or soil bands that are generated during the mining process and are dumped near the marked placed inside the mine boundaries. It contains alluvial, sandstone, soil, gravel, clay, debris other than mining material. Dumping or management of this mine waste is a significant environmental problem, and additional cost spends to the mining industry. And also, most of this waste is disposed of at the surface, which inevitably requires extensive planning. Sand and gravel are low energy-intensive construction materials, but the growing demand for industrial uses has depleted this natural source. Limitations to natural sand extraction and legal regulations have been imposed in several countries due to environmental concerns. Due to the above, all the reasons river sand has become very costly in recent years. The research has been carried out to convert the overburden to processed overburden sand after that compared the geotechnical properties like specific gravity, permeability, moisture content, and grain size analysis, swell factor of both the overburden processed sand and natural river sand. Then we check the suitability of processed overburden material as a replacement to natural river sand in construction by comparing the strengths of the concrete samples prepared with both the river sand and processed overburden sand. We found the average compressive strength of overburden sand brick is 24.69 MPa, and river sand brick is 28.08 MPa of 14 days curing of bricks. The results obtained that the processed overburden sand can be used as the best alternative for the river sand because the geotechnical properties of both are almost the same. This processed overburden utilization in the coal mining area to reduced environmental impact, more availability of a land resource, minimizing the overburden disposable cost to the mining industry, and it’s also helpful to the preservation of natural river sand.


2020 ◽  
Author(s):  
Olumuyiwa Olusola Falowo

Abstract Geotechnical investigation was carried out at two failed segments along Ifon-Benin Highway, with the aim of determining cause, nature, and extent of the road failure. Eight in-situ cone penetration tests was carried out to a depth of about 20 m with a lateral spacing of 20 m. This was complemented by collection of eight soil samples at different depths within the failed segments and analyzed in the laboratory. The laboratory tests conducted were grain size analysis, Atterberg limit test, compaction test, California bearing ratio, undrained unconfined triaxial test. The failure that existed in both locations are around the embankment, shoulder/edge and wearing course of the highway, due to ingression of water into the subgrade since the earth (natural soil) embankment structure had been eroded by rain water. The laboratory geotechnical results revealed that all the parameters could not meet up with the federal ministry of works and housing specification of Nigeria, with plasticity index greater than 20 %, % fines greater than 35 %, CBR values less than 80 % minimum recommended, shear strength parameters; angle of friction and cohesion are less than minimum of 30° and 50 kPa respectively. The CPT revealed predominant sandy silt to clayey silt topsoil and clay substratum with an inferred compressive strength of 20 – 40 KN/m2. At both failed segments, the clayey substratum is seriously affected within the upper 6 m. The ingression of water into these foundation structures was due to compromise of the design/construction engineer, since a bridge was supposed to be erected across these two locations. Hence the stream channels across the highway were blocked by the earth-fill embankment. Therefore during wet season, pool of water that supposed to flow across the road through bridge system, continue to dissolve the embankment, and consequently infiltrate into the subgrade. This makes the highway to settle largely under traffic load. In addition, incessant heavy flooding around the embankment/shoulder of the highway might have induced the failure since a bridge was supposed to have been constructed across the two failed segments. This flooded water might have infiltrated into the pavement structural material leading to looseness, and less-cohesion of the layers which invariably reduces subgrade support and weakens various pavement layers.


Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Srećko Bevandić ◽  
Rosie Blannin ◽  
Jacqueline Vander Auwera ◽  
Nicolas Delmelle ◽  
David Caterina ◽  
...  

Mine wastes and tailings derived from historical processing may contain significant contents of valuable metals due to processing being less efficient in the past. The Plombières tailings pond in eastern Belgium was selected as a case study to determine mineralogical and geochemical characteristics of the different mine waste materials found at the site. Four types of material were classified: soil, metallurgical waste, brown tailings and yellow tailings. The distribution of the mine wastes was investigated with drill holes, pit-holes and geophysical methods. Samples of the materials were assessed with grain size analysis, and mineralogical and geochemical techniques. The mine wastes dominantly consist of SiO2, Al2O3 and Fe2O3. The cover material, comprising soil and metallurgical waste is highly heterogeneous in terms of mineralogy, geochemistry and grain size. The metallurgical waste has a high concentration of metals (Zn: 0.1 to 24 wt.% and Pb: 0.1 to 10.1 wt.%). In the tailings materials, Pb and Zn vary from 10 ppm to 8.5 wt.% and from 51 ppm to 4 wt.%, respectively. The mining wastes comprises mainly quartz, amorphous phases and phyllosilicates, with minor contents of Fe-oxide and Pb- and Zn-bearing minerals. Based on the mineralogical and geochemical properties, the different potential applications of the four waste material types were determined. Additionally, the theoretical economic potential of Pb and Zn in the mine wastes was estimated.


2021 ◽  
Vol 11 (6) ◽  
pp. 2799
Author(s):  
Yanping Chen ◽  
Wenzhe Lyu ◽  
Tengfei Fu ◽  
Yan Li ◽  
Liang Yi

The Huanghe River (Yellow River) is the most sediment laden river system in the world, and many efforts have been conducted to understand modern deltaic evolution in response to anthropological impacts. However, the natural background and its linkage to climatic changes are less documented in previous studies. In this work, we studied the sediments of core YDZ–3 and marine surface samples by grain-size analysis to retrieve Holocene dynamics of the Huanghe River delta in detail. The main findings are as follows: The mean value of sediment grain size of the studied core is 5.5 ± 0.9 Φ, and silt and sand contents are 5.2 ± 2.3% and 8.2 ± 5.3%, respectively, while the variance of clay particles is relatively large with an average value of 86.4 ± 8.5%. All grain-size data can be mathematically partitioned by a Weibull-based function formula, and three subgroups were identified with modal sizes of 61.1 ± 28.9 μm, 30.0 ± 23.9 μm, and 2.8 ± 1.6 μm, respectively. There are eight intervals with abrupt changes in modal size of core YDZ–3, which can be correlated to paleo-superlobe migration of the Huanghe River in the Holocene. Based on these observations, the presence of seven superlobes in the history are confirmed for the first time and their ages are well constrained in this study, including Paleo-Superlobes Lijin (6400–5280 yr BP), Huanghua (4480–4190 yr BP), Jugezhuang (3880–3660 yr BP), Shajinzi (3070–2870 yr BP), Nigu (2780–2360 yr BP), Qikou (2140–2000 yr BP), and Kenli (1940–1780 and 1700–1650 yr BP). By tuning geomorphological events to a sedimentary proxy derived from core YDZ–3 and comparing to various paleoenvironmental changes, we proposed that winter climate dominated Holocene shifts of the Huanghe River delta on millennial timescales, while summer monsoons controlled deltaic evolution on centennial timescales.


2020 ◽  
Vol 11 (1) ◽  
pp. 230
Author(s):  
Hoil Lee ◽  
Jin-Young Lee ◽  
Seungwon Shin

We obtained a 15 m drill core from Deukryang Bay on the southwest coast of Korea, which is now an area of reclaimed land used for agriculture. We investigated changes in the depositional environment and hydrological climate responses to sea level changes using sedimentary facies, radiocarbon ages, grain-size analysis, total organic carbon (TOC), total sulfur (TS), and stable carbon isotopes (δ13C). Sediment deposition began at 12,000 cal yr BP and was divided into four stages based on changes from fluvial to intertidal environments related to Holocene marine transgression events. Stage 1 (>10,000 cal yr BP) is represented by fluvial sediments; Stage 2 (10,000–7080 cal yr BP) is represented by the deposition of mud facies in an intertidal zone in response to sea level rise; Stage 3 (7080–3300 cal yr BP) was a period of gradually descending sea level following the Holocene maximum sea level and is characterized by gradual changes in TOC, TS, and C/S ratios compared with the mud facies of Stage 2. Stage 4 (3300 to present) was deposited in a supratidal zone and contains low TS and an abundance of TOC. Based on our TS and C/S ratio results, the south coast of Korea was mainly affected by sea level rise between 7000 and 3000 cal yr BP, during the middle Holocene. At 3000 cal yr BP, sea level began to stabilize or gradually decrease. In addition, changes in δ13C values are clearly observed since ca. 5000 cal yr BP, in particular, large hydrological changes via freshwater input are confirmed in 4000–3000 cal yr BP. We consider these shifts in freshwater input indicators of an increased influence of El Niño and La Niña conditions, related to the weakening of the East Asian Summer Monsoon (EASM) and changes in sea surface temperature (SST) of the Western Pacific Ocean during the middle Holocene climatic optimum (between 7800 and 5000 cal yr BP). The cooling periods of SST in East Asia between 8400 and 6600 cal yr BP reported from the west coast of Korea are related closely to changes in vegetation (as evidenced by δ13C) from 7700 cal yrs BP to the present in the southwest coast of Korea. We interpret the freshwater input events at 4000–3000 cal yr BP to be related to changes in SST in response to the weakening of the EASM on the southwest coast of Korea. However, additional research is needed to study the southward migration effect of the westerly jet related to SST and atmospheric circulation controlling terrestrial climate in the middle Holocene.


2015 ◽  
Vol 773-774 ◽  
pp. 1438-1442 ◽  
Author(s):  
Siti Aimi Nadia Mohd Yusoff ◽  
I. Bakar ◽  
Devapriya Chitral Wijeyesekera ◽  
Adnan Zainorabidin ◽  
Aziman Madun

This paper compares some geotechnical properties of Kaolin, Laterite and Peat. Laterite was collected from Bukit Banang while Peat sample was collected from Parit Nipah, both locations were in Batu Pahat, Johor. Meanwhile, kaolin that was used in this research was manufactured kaolin. These soil samples were subjected to routine laboratory analysis and resulting data were analyzed statistically using a correlation analysis. A laboratory testing program consists of “Basic properties test” to obtain general information on the materials (e.g Natural moisture content, Atterberg Limit, Specific gravity, grain size analysis, chemical composition and pH) and “Geotechnical properties tests” to measure specific properties that characterize soil behaviour for design and constructability assessments (e.g Standard Proctor Test, Unconfined Compressive Strength and CBR).The results showed that the Natural/initial moisture content for laterite, peat and kaolin is 22.54%, 480.61% and 0.22% respectively. Meanwhile Specific gravity for each soil was in the range 1.50-2.79.It was also found that the pH of all soil is acidic which lay in the range of 3.76-5.95.The UCS for the optimally compacted sample of laterite is 445.77 kPa, kaolin is 199.23 kPa and for peat is 58.70 kPa. This paper summarizes the result of analysis performed on all tests conducted. Based on the results, the geotechnical property of the soil is a highly dependent with the type of soil and therefore, determining the soil characterization and the soil strength should be considered during the planning phase of any earthwork construction operation.


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