scholarly journals Study on the Bearing Characteristics and Application of the Filling Body in Original Roadway Filling and Nonpillar Driving

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 4) ◽  
Author(s):  
Wenbao Shi ◽  
Yan Li ◽  
Jucai Chang
Keyword(s):  
Water Content ◽  
Coal Mining ◽  
High Water ◽  
High Water Content ◽  
Working Face ◽  
Geological Conditions ◽  
Analysis Laboratory ◽  
The Stability ◽  
And Control

Abstract Original roadway filling and nonpillar driving can effectively solve the difficulty facing mining replacement in the stope of deep mines. As the bearing characteristics of the filling body in the original roadway play a crucial role in the structural stability of the overlying strata, with the recovery and geological conditions of 62210 working face in Xinzhuangzi Coal Mine, Huainan Mining Group, China, as the background, this study analyzed the stability characteristics of the filling body in the original roadway through comprehensive research methods of theoretical analysis, laboratory tests, and onsite monitoring. The results disclose that the filling body in the original roadway should boost early strength, strong bearing capacity, and long-term weakening. When the water-cement ratios are 1 : 1, 1.5 : 1, 2 : 1, 2.5 : 1, and 3 : 1, the strengths of the filling body are 1.12 MPa, 0.93 MPa, 0.57 MPa, 0.33 MPa, and 0.21 MPa at 2 h and 5.63 MPa, 4.66 MPa, 2.87 MPa, 1.65 MPa, and 1.02 MPa at 48 h, respectively. The strengths surge by 5 times within 2 d on the whole and reach the maximum at about 7 d, i.e., 8.12 MPa, 6.91 MPa, 6.60 MPa, 3.95 MPa, and 2.20 MPa, respectively. As time goes, the water content of the filling body gradually decreases and the compressive strength plunges. This demonstrates that the rapid solidification material with a high water content can satisfy the requirements of the bearing characteristics of the original roadway filling body. With reference to numerical simulation and the data monitored onsite, it can be known that the filling body in the original roadway can support the roof effectively and control the surrounding rock deformation of newly excavated roadways in the lower section. The research results provide theoretical guidance for coal mining under similar geological conditions and serve as reference for safe and efficient coal mining.

scholarly journals Stability of cactus-pear powder during storage

2016 ◽  
Vol 20 (2) ◽  
pp. 169-173
Author(s):  
Plúvia O. Galdino ◽  
Rossana M. F. de Figueirêdo ◽  
Alexandre J. de M. Queiroz ◽  
Pablícia O. Galdino ◽  
Tâmila K. da S. Fernandes
Keyword(s):  
Water Content ◽  
Water Activity ◽  
Reducing Sugars ◽  
Titratable Acidity ◽  
High Water ◽  
Soluble Solids ◽  
High Water Content ◽  
Cactus Pear ◽  
Total Titratable Acidity ◽  
The Stability

ABSTRACT The stability of cactus-pear powder, obtained by the process of spray drying for 40 days, was evaluated under controlled conditions of relative air humidity (83%) and temperature (25 and 40 °C). The whole pulp was characterized with regard to its physico-chemical parameters: pH, total titratable acidity, soluble solids, water content, total solids, ashes, reducing sugars, total sugars, non-reducing sugars, luminosity, redness, yellowness and water activity. The stored samples in powder were evaluated every 10 days for water content, water activity, total titratable acidity and color (luminosity, redness and yellowness). The whole pulp was slightly acidic and perishable, due to the high water content. During storage, the packages did not prevent water absorption, thus increasing water content and, consequently, water activity. Yellowness oscillated along the storage time, but the predominance of the yellow color was not affected.

Empirical settlement predictions in overconsolidated Champlain Sea clays

2001 ◽  
Vol 38 (4) ◽  
pp. 720-731 ◽  
Author(s):  
Luc Morissette ◽  
Michel W St-Louis ◽  
Gordon C McRostie
Keyword(s):  
Water Content ◽  
Correction Factor ◽  
Empirical Model ◽  
High Water ◽  
High Water Content ◽  
Overconsolidation Ratio ◽  
Compressibility Index ◽  
Marine Clays

Using settlement observations published for several embankments on marine clays of the Champlain Sea, an empirical model is proposed to estimate long-term settlements. The effect of the overconsolidation ratio is taken into consideration within the model. Footing- and raft-type foundation cases are considered to give guidelines when using the model for these foundation types. A specific embankment resting on a foundation of high water content clay with a high compressibility index demonstrates that a correction factor should be applied under these conditions.Key words: settlement, embankment, Champlain Sea clay, consolidation, empirical model.

scholarly journals Analisis Formalin Secara Kualitatif pada Bakso dan Mie Basah di Kecamatan Sukarame, Wayhalim, dan Sukabumi

KOVALEN ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 218-223
Author(s):  
Riri Fauziyya ◽  
Anjar Hermadi Saputro
Keyword(s):  
Qualitative Analysis ◽  
Water Content ◽  
Food Products ◽  
High Water ◽  
High Water Content ◽  
Food Preservatives ◽  
Maximum Profit ◽  
Positive Results

Meatballs and wet noodles are foods that are favored by the community. The high water content causes these two types of food to be vulnerable and easily damaged in storage. The addition of chemicals such as preservatives in the manufacture of food products is carried out by producers so that the products are more durable, economical, and produce maximum profit. One chemical that is often misused for food preservatives is formaldehyde. Formalin is a dangerous chemical that is carcinogenic, mutagenic, corrosive, and irritating. This study aims to determine whether there is formalin content in meatballs and wet noodles that are sold in the districts of Sukarame, Wayhalim, and Sukabumi. This research was conducted in a qualitative analysis using Schiff's reagent on 30 samples of meatballs and 30 samples of wet noodles which were sold in Sukarame, Wayhalim, and Sukabumi. The results showed that 10 samples of meatballs and 2 wet noodles showed positive results containing formaldehyde.  This shows that around 33.3% of the meatball sample and 6.66% of the wet noodles sample analyzed were identified to contain formaldehyde so that they are not safe for consumption in the long term and people must be careful in selecting meatballs and wet noodles for consumption. Keywords: Qualitative analysis, formalin, meatballs, wet noodles

scholarly journals Field Treatment of Storage Sludge and Stability Analysis of Overlying Municipal Waste Landfilling

2021 ◽  
Vol 11 (24) ◽  
pp. 12102
Author(s):  
Kaixi An ◽  
Duanyang Zhuang ◽  
Weian Lin ◽  
Albert Argilaga ◽  
Yunmin Chen ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Water Content ◽  
Limit Equilibrium ◽  
High Sensitivity ◽  
High Water ◽  
Treatment Method ◽  
Strength Properties ◽  
High Water Content ◽  
Critical Surface ◽  
The Stability

Storage sludge has high water content and low shear strength, which limits the capacity expansion of overlying municipal landfilling. Few studies have addressed the field treatment of large amounts of storage sludge due to the variability of the depth of geotechnical property. This paper proposes a stratified treatment method for storage sludge, based on the in situ characterization of layered sedimentary patterns of the storage sludge acquired from the Qizishan landfill in China. Additionally, the stability of the landfilling above the sludge pond is analyzed using the Morgenstern–Price and limit equilibrium slice method, which considers the layered strength properties of solidified sludge. The treated sludge has a significant decrease in average water content from 1398% to 88% and an increase in average cohesion to 23.52 kPa. The high content of clay particles, low amount of solidification products, and high water content together result in the high sensitivity to the water content of the strength of deep solidified sludge. For a 40-m high waste body, stability analysis suggests a sliding surface across the raw sludge pond, while the critical surface remains outside the treated sludge pond and the safety factor is increased from 0.934 to 1.464. The validated stratified treatment provides valuable references for the treatment of deep sludge.

Long-Term Performance Study of High Moisture Content Cohesive Soil Subgrade in Seasonal Frozen Region

2013 ◽  
Vol 405-408 ◽  
pp. 49-56
Author(s):  
Sheng Chuan Liu ◽  
Gui Ling Ding ◽  
Gang Chen
Keyword(s):  
Theoretical Analysis ◽  
Water Content ◽  
High Water ◽  
High Water Content ◽  
Test Field ◽  
Frozen Ground ◽  
Freeze Thaw ◽  
Long Term Performance ◽  
Term Performance

This project is aiming at the high water content clay in seasonally frozen ground region, based on the expressway program in Heilongjiang province. By applying laboratory test, field test, field monitoring and theoretical analysis, research has been proposed to understand the deformation law and long-term performance of high water content clay subgrade in freeze-thaw condition. From the comparison test of soil and soil treated with lime, road properties of high water content clay has been found out. It is a very necessary and effective method using lime to treat the high water content clay in subgrade construction. Laboratory freeze-thaw experiments uncover the strength weakening law of soil treated with lime. With theoretical analysis and numerical calculation, the interaction between clayey subgrade and pavement structure layer under effect of vehicle dynamic load is analyzed. According to this result, control standards of subgrade frost heave in seasonally frozen ground region and subgrade resilience modulus in spring have been proposed.

scholarly journals Strength and Leaching Behavior of Contaminated Mining Sludge at High Water Content Stabilized with Lime Activated GGBS

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6524
Author(s):  
Traore Abdoul Fatah ◽  
Rongjun Zhang ◽  
Xiaosong Huang ◽  
Junjie Zheng ◽  
Yu Miao ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Water Content ◽  
Experimental Tests ◽  
High Water ◽  
Aluminum Silicate ◽  
High Water Content ◽  
Strength Development ◽  
Efficient Technology ◽  
The Stability ◽  
Mining Sludge

Sludge management is one of the major challenges in mining activities. The direct disposal of contaminated mining sludge can bring severe damages to the environment and community. Solidification/stabilization (S/S) is a very efficient technology for the treatment of contaminated mining sludge because it improves the stability of sludge dumping sites and reduces the leachability of contaminants. Very few studies investigate the S/S of mining sludge, especially with high water content. This paper investigated the effectiveness of S/S for the treatment of mining sludge at high water content by using quick lime (CaO) activated ground granulated blast furnace slag (GGBS) in comparison to ordinary Portland cement (OPC). To evaluate the mechanical, leaching, and microstructural behavior of CMS at high water content stabilized by lime-activated GGBS and OPC, a series of laboratory experimental tests were performed. Experimental results indicated that increasing the dosage of binder led to increased strength and decreased leachability of the heavy metal. In contrast, an increase in the water content of the mixture resulted in a decrease in compressive strength and an increase in the leachability of heavy metals. On the other hand, lime-activated GGBS mixes had substantially better performance than OPC mixes in the aspect of strength development of treated mining sludge and showed comparable capability of heavy metal stabilization compared to OPC. The microstructural tests revealed the formation of different hydration products such as calcium silicate hydrate, calcium aluminum silicate hydrate, ettringite, hydrotalcite, and heavy metal complexes in CG and OPC mixes.

scholarly journals Investigation of the Optimal Layout of the Roadway in Closely Spaced Ultra-Thick Coal Seams Mining with Remaining Coal Pillars

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Bin Zhao ◽  
Le Gao ◽  
Xianghui Tian ◽  
Yingyu Sun
Keyword(s):  
Stress Reduction ◽  
Site Investigation ◽  
High Water ◽  
High Water Content ◽  
Thick Coal Seam ◽  
Working Face ◽  
Mining Safety ◽  
Coal Pillars ◽  
The Stability ◽  
Seam Mining

The reasonable layout of the roadway in closely spaced, ultra-thick coal seam mining is of great significance to mining safety. Based on the research background of repeated roof leaks in the process of repairing the return air roadway in working face No. 30503 in the Tashan Coal Mine, theoretical analysis, in situ engineering testing, and numerical simulation were jointly adopted to evaluate the stability of the return air roadway under two schemes of repairing the original return air roadway and excavating a new return air roadway. The results show that the vertical mining-induced fissure above the roadway will cause severe damage to the roadway due to the influence of working-face mining when restoration of the roadway excavation is adopted. When choosing to excavate a new return air roadway, the new return air roadway just staggers the vertical cracks located in the top slab of the original return air roadway, putting the roadway in a state of stress reduction, making the roadway itself more stable and conducive to support. Therefore, the new air return tunnel was selected to establish the working face. To ensure safety of the working face during the mining of the original return air roadway, the original return air roadway was filled with high water content materials. Site investigation data show that this material plays a cushioning role in the filling section of the original return air roadway during the mining of the 30503 working face, and the deformation of the new return air roadway during the filling section crossing the original return roadway is stable and well controlled.

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