Experimental Research on Simulation Material for Water-Resisting Soil Layer in Mining Physical Simulation

This paper focuses on the failure mechanism of a water-resisting soil layer with both coal excavation and seepage effect. Being taken the simulation principle of fluid-solid coupling as the research basis, we have established a new kind of experimental material for fluid-solid physical simulation (FPS). The material adopts river sand and clay as the aggregates, besides engine oil and low-temperature grease that are used as the gelatinizing agents. According to the relevant property testing on the experimental material, the mechanical parameters and seepage parameters of the material totally match the parameters of the soil layer, which satisfy requirements of the fluid-solid coupling experiment. Simultaneously, we have solved abundant material property problems, such as the material disintegration with water and visuality of water seepage in the simulation. Next, we have built up the FPS model to simulate coal excavation under water-bearing strata with the specific material. The results indicated that in the FPS, movement and failure mechanism of the water-resisting soil layer agree with the in-situ monitoring results. In addition, the revolution law of a mining-induced crack is also fitting the actual data. The mechanism of submarine seepage and its parameters on the material and the prototype are similar. All research results would be necessary for controlling mining-induced destroying of clay water-resisting property. Meanwhile, the model demonstrates that selection of the material and coupling parameters is valid. Finally, we can alter the material matching to obtain the layer materials with various characteristics, which would be applied in extensive experiments for studying soil layer failure and seepage simulation.

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Detecting the landslide vulnerability in the epicentre of Wenchuan Earthquake via SBAS-InSAR method

10.5194/egusphere-egu2020-3907 ◽

2020 ◽

Author(s):

Wenjiang Zhang

Keyword(s):

Wenchuan Earthquake ◽

Soil Layer ◽

In Situ Monitoring ◽

Ground Subsidence ◽

In Situ Observation ◽

Interferometric Synthetic Aperture Radar ◽

Multi Temporal ◽

Sbas Insar ◽

River Valleys

Valleys in the epicentre of Wenchuan Earthquake (Sichuan Province, China) are severely subjected to landside risks partially due to the persistent influences of the serious earthquake in 2008. Without enough regionally in-situ monitoring measures, the method of multi-temporal, differential interferometric synthetic aperture radar (D-InSAR) provides an efficient to monitor the surface subsidence and thus the landslide vulnerability. In this&#160;study,&#160;we used the Sentinel Satellite Images (2015-2018) to extract the subsidence information along river valleys near the Wenchuan Earth epicentre, which was well validated by the in-situ observation of one GPS station (RSME=1.6 cm, p<0.01). Our results showed the persistent ground subsidence (1.5 mm yr-1, p<0.01) at many places, which was also related to terrain aspect besides to the well-proved conditions of slope, vegetation cover and soil layer. This fact that implied the terrain aspect should be taken into accounts in landside vulnerability analyses, because precipitation is locally more abundant in windward places. Results emphasized the higher vulnerability of landslide in summer, which could be attributed to more precipitation during summer in the study area. Our study extracted over 100-km valleys (and especially ~50 places) with high landslide vulnerability (subsidence rate > 1.20 mm yr-1), which should be paid high-prior careful attentions so as to avoid potential geological disasters.

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Study on the Settlement Correction Coefficient in Seawall Engineering Based on In Situ Monitoring Data

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.170-173.2195 ◽

2012 ◽

Vol 170-173 ◽

pp. 2195-2199

Author(s):

Jiong Qi Yu ◽

Shen Qiu Han ◽

Xiong Wei Wu

Keyword(s):

In Situ Monitoring ◽

Monitoring Data ◽

Correction Coefficient ◽

The Real ◽

Site Monitoring ◽

Total Settlement ◽

Systematic Selection ◽

Selection Of

The selection of the settlement correction coefficient is difficult in the design of seawall engineering. Two cases were enumerated, the settlement correction coefficients were back calculated using in situ monitoring data. The settlement correction coefficients derived from site monitoring fitted total settlement ranged between 1.94 and 2.78. They are much larger than 1.3 applied in design in two cases, and they exceed the recommended range of 1.2 to 1.8. The results indicate that the settlement correction coefficient given in design is lack of a scientific and systematic selection basis and it can hardly reach the real settlement of seawall engineering. The job of in situ monitoring is a good guidance to the selection of the settlement correction coefficient for similar projects in this area.

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In situ monitoring of high-temperature degraded engine oil condition with microsensors

Sensors and Actuators B Chemical ◽

10.1016/0925-4005(93)01168-4 ◽

1994 ◽

Vol 20 (1) ◽

pp. 49-54 ◽

Cited By ~ 15

Author(s):

Han-Sheng Lee ◽

Simon S. Wang ◽

Donald J. Smolenski ◽

Michael B. Viola ◽

Edward E. Klusendorf

Keyword(s):

High Temperature ◽

In Situ Monitoring ◽

Engine Oil

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Subsidence Prediction of Overburden Strata and Ground Surface in Shallow Coal Seam Mining

10.21203/rs.3.rs-393197/v1 ◽

2021 ◽

Author(s):

Jian Cao ◽

Qingxiang Huang ◽

Lingfei Guo

Keyword(s):

Coal Seam ◽

Physical Simulation ◽

Soil Layer ◽

Ground Surface ◽

In Situ Observation ◽

Key Stratum ◽

Shallow Coal Seam ◽

Seam Mining ◽

Overburden Strata

Abstract Shallow coal seam with thick soil layer is widely reserved in the Jurassic Coalfield, Western China, mining-induced subsidence represents complex characteristics. Combining with physical simulation, theoretical analysis and in-situ observation, the overburden strata structure in dip direction were revealed, and the subsidence prediction models were established, based on this, the subsidence equations of overburden strata and ground surface were proposed. The results show that after shallow coal seam mining, based on the subsidence and movement characteristics, the overburden strata structure can be divided into three zones, which are "boundary pillar F-shape zone" (BPZ), "trapezoid goaf zone" (TGZ) and "coal pillar inverted trapezoidal zone" (CPZ). The subsidence of overburden strata depends on the key stratum, while the subsidence of soil layer depends on the bedrock subsidence basin, which is between the bedrock and thick soil layer. The bedrock subsidence is mainly related to mining height and bulking coefficient in TGZ, while it is mainly affected by mining height and distribution load on the key stratum in BPZ and CPZ. According to physical simulation and theoretical model, the maximum surface subsidence of No.1–2 seam mining in Ningtiaota coal mine are 1.1m and 1.07m respectively, which is basically consistence with the result of in-situ observation (1.2m).

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Subsidence prediction of overburden strata and ground surface in shallow coal seam mining

Scientific Reports ◽

10.1038/s41598-021-98520-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jian Cao ◽

Qingxiang Huang ◽

Lingfei Guo

Keyword(s):

Coal Seam ◽

Physical Simulation ◽

Soil Layer ◽

Ground Surface ◽

In Situ Observation ◽

Key Stratum ◽

Shallow Coal Seam ◽

Seam Mining ◽

Overburden Strata

AbstractShallow coal seam with thick soil layer is widely reserved in the Jurassic Coalfield, Western China, mining-induced subsidence represents complex characteristics. Combining with physical simulation, theoretical analysis and in-situ observation, the overburden strata structure in dip direction were revealed, and the subsidence prediction models were established, based on this, the subsidence equations of overburden strata and ground surface were proposed. The results show that after shallow coal seam mining, based on the subsidence and movement characteristics, the overburden strata structure can be divided into three zones, which are "boundary pillar F-shape zone" (BPZ), "trapezoid goaf zone" (TGZ) and "coal pillar inverted trapezoidal zone" (CPZ). The subsidence of overburden strata depends on the key stratum, while the subsidence of soil layer depends on the bedrock subsidence basin, which is between the bedrock and thick soil layer. The bedrock subsidence is mainly related to mining height and bulking coefficient in TGZ, while it is mainly affected by mining height and distribution load on the key stratum in BPZ and CPZ. According to physical simulation and theoretical model, the maximum surface subsidence of No.1-2 seam mining in Ningtiaota coal mine are 1.1 m and 1.07 m respectively, which is basically consistence with the result of in-situ observation (1.2 m).

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