scholarly journals Foundation Methods for the Soft Ground Reinforcement of Lightweight Greenhouse on Reclaimed Land: A review

2020 ◽  
Vol 29 (4) ◽  
pp. 440-447
Author(s):  
이름 저자 성 ◽  
이름 저자 성 ◽  
Su Hwan Lee
Keyword(s):  
Author(s):  
Andrey ilinsky ◽  
Alexander Nefedov ◽  
Konstantin Evsenkin

Global climatic changes, technogenic pollution by pollutants, violations of technologies of exploitation of reclaimed land lead to a decrease in fertility and soil degradation of agricultural land. Adverse weather conditions, resulting in a lack of adequate flood water, and economic difficulties in agriculture make it difficult to fill the deficit of organic matter and macronutrients in reclaimed alluvial soils. The monitoring of agrochemical properties of alluvial meadow medium-loamy soil of the stationary site (reclaimed lands of JSC «Moskovskoye» of Ryazan region), located in the floodplain of the Oka river, conducted by the Meshchersky branch of Vniigim, showed the presence and intensification of degradation changes in the soil. Thus, comparing the agrochemical indicators in the layer 0–20 cm, carried out in 1995, with the indicators of 2019, it should be noted a decrease in soil fertility. The decrease in soil quality was expressed in a decrease in the amount of mobile phosphorus by 37.6 %, mobile potassium by 53.3 %. Also, during this time there was a decrease in organic matter by 9.1 %, and an increase in soil acidity was 0.6 pH. As a result of such changes, soils lose ecological stability and become more vulnerable to adverse weather and negative anthropogenic impacts. In such a situation, advanced agricultural techniques should be actively used to obtain guaranteed, environmentally safe crop yields and restore the fertility of degraded reclaimed soils. In this regard, there is a need to develop innovative methods of fertility restoration of degraded alluvial soils in reclaimed lands using multi-component organic-mineral ameliorants. Meshchersky branch performs research work in addressing this issue.


2018 ◽  
Vol 25 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Seon-Deok Jin ◽  
In Hwan Paik ◽  
Chi Young Park ◽  
Seong Hoon Choi ◽  
Jae Pyeong Yu ◽  
...  

Author(s):  
Anne Lemnitzer

We are excited to present the work of five excellent author groups who prepared the research papers and case studies featured in this Issue. Three of the five papers deal with piles and the remaining two papers involve foundation construction on soft ground conditions.


2007 ◽  
Vol 17 (1) ◽  
pp. 1-30
Author(s):  
S.H. Zainud-Deen ◽  
E. El-Deen ◽  
H.A. Sharshar ◽  
M. A. Binyamin

Author(s):  
Mari Maeda ◽  
Mari Maeda ◽  
Yasunori Kozuki ◽  
Yasunori Kozuki ◽  
Ken Hirai ◽  
...  

In 2006, Hyogo prefecture opened the “Araihamakaze” park on reclaimed land leased with cooperation from some companies, and set up a seawater pond called “Konourafuna Ike” in the park. The initial plan was to make this seawater pond into a Satoumi, but since the water in the pond was stagnant, algae flourished making it uninhabitable for other living creatures. The authors conducted investigative research to implement activities for improving the environment and popularizing the park. This report is a summary of the results obtained and challenges faced while conducting these activities in the area over one year, which included involving the local schoolchildren in constructing tidal flats. The answers to the questionnaire revealed that schoolchildren understood that the nutrients in the seawater pond “go round and round” through the food chain and are utilized by living creatures. They realized that this process is called “circulation.”To the question, “Do you want to develop tidal flats?” 9 of the 10 children answered YES. However, only 50% of the children understood that a measure to prevent the degradation of the environment of the seawater pond is to “Construct tidal flats,” which suggested that there is a need to correlate the issues and the solutions to enhance their understanding.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2838
Author(s):  
Xiaoxing Zhang ◽  
Haoyuan Yi ◽  
Junjun Liu ◽  
Qi Li ◽  
Xin Luo

There has been a rising interest in compliant legged locomotion to improve the adaptability and energy efficiency of robots. However, few approaches can be generalized to soft ground due to the lack of consideration of the ground surface. When a robot locomotes on soft ground, the elastic robot legs and compressible ground surface are connected in series. The combined compliance of the leg and surface determines the natural dynamics of the whole system and affects the stability and efficiency of the robot. This paper proposes a bio-inspired leg compliance planning and implementation method with consideration of the ground surface. The ground stiffness is estimated based on analysis of ground reaction forces in the frequency domain, and the leg compliance is actively regulated during locomotion, adapting them to achieve harmonic oscillation. The leg compliance is planned on the condition of resonant movement which agrees with natural dynamics and facilitates rhythmicity and efficiency. The proposed method has been implemented on a hydraulic quadruped robot. The simulations and experimental results verified the effectiveness of our method.


2021 ◽  
Vol 11 (14) ◽  
pp. 6425
Author(s):  
Hidenori Takahashi ◽  
Shinya Omori ◽  
Hideyuki Asada ◽  
Hirofumi Fukawa ◽  
Yusuke Gotoh ◽  
...  

Cellulose nanofibre (CNF), a material composed of ultrafine fibres of wood cellulose fibrillated to nano-order level, is expected to be widely used because of its excellent properties. However, in the field of geotechnical engineering, almost no progress has been made in the development of techniques for using CNFs. The authors have focused on the use of CNF as an additive in cement treatment for soft ground, where cement is added to solidify the ground, because CNF can reduce the problems associated with cement-treated soil. This paper presents the results of a study on the method of mixing CNF, the strength and its variation obtained by adding CNF, and the change in permeability. CNF had the effect of mixing the cement evenly and reducing the variation in the strength of the treated soil. The CNF mixture increased the strength at the initial age but reduced the strength development in the long term. The addition of CNF also increased the flexural strength, although it hardly changed the permeability.


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.


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