scholarly journals Development characteristic and formation mechanism analysis of collapse sinkholes in Wugaishan town, Chenzhou city, Hunan province, China

2021 ◽  
Author(s):  
Zongyuan Pan ◽  
Xuejun Chen ◽  
Xin Yang ◽  
Yu Song ◽  
Rulong Ban ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Groundwater Level ◽  
Strong Relationship ◽  
Bottom Layer ◽  
Hunan Province ◽  
Mechanism Analysis ◽  
Zonal Distribution ◽  
Collapse Sinkhole ◽  
Unconsolidated Material ◽  
Overburden Material

Abstract The cover collapse sinkholes occurred and concentrated in Wugaishan town, Chen zhou city since 1996. The results are combined with results of site investigation, geophysical prospecting and in situ groundwater monitoring data, allowing the development characteristics and formation mechanism of surficial collapse incidents to be summarized. Collapse sinkholes are significantly active in recent years and mostly develop in the rainy season ranging from April to June and generally show a zonal distribution along the topography of study area from SW to NE. 92.31 % of total collapse events occurred in the thickness of overburden material ranged from 0 to 15 m, which indicated that overlying material less than 15 m was easier to collapse. The results show that collapse sinkholes have strong relationship with characteristic of overburden material, which sharply decrease in internal physical and mechanical property of bottom layer. Furthermore, substantial cavities formed within bedrock are the best transport channels and storage spaces for the unconsolidated material, especially under the condition of dynamic undulation of groundwater level. The formation mechanism of collapse sinkhole is divided into three types: infiltration erosion, coupling air implosion with vacuum cavitation and saturation erosion. Each formation mechanism is related to changes of groundwater level. When groundwater level rose above the soil-bedrock interface, saturated subsoil were easier to disintegrate into small particles and migrate downward as the vertical seepage of groundwater. The hydraulic gradient increased and became the predominant factor for the development of soil cavity as groundwater level dropped below the soil-bedrock interface. Moreover, when groundwater level sharply surged up at the relative sealed environment, the upward erosion roof of cavity would be more likely to collapse by the entrapped air blasting.

scholarly journals The custom making of hierarchical micro/nanoscaled titanium phosphate coatings and their formation mechanism analysis

RSC Advances ◽  
2019 ◽  
Vol 9 (70) ◽  
pp. 41311-41318 ◽  
Author(s):  
Bianyun Cai ◽  
Nan Jiang ◽  
Peijie Tan ◽  
Yi Hou ◽  
Yubao Li ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Titanium Phosphate ◽  
Mechanism Analysis ◽  
Phosphate Coatings ◽  
Surface Morphologies

In this study, a series of hierarchical micro/nanoscaled titanium phosphate (TiP) coatings possessing various surface morphologies were successfully fabricated on titanium (Ti) discs.

Formation mechanism analysis of irrigation-induced retrogressive loess landslides

CATENA ◽  
2020 ◽  
Vol 195 ◽  
pp. 104441 ◽  
Author(s):  
Baoqin Lian ◽  
Jianbing Peng ◽  
Hongbin Zhan ◽  
Qiangbing Huang ◽  
Xingang Wang ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Mechanism Analysis ◽  
Loess Landslides

scholarly journals GEOPHYSICAL INVESTIGATIONS OF A POTENTIAL LANDSLIDE AREA IN MAYOON, HUNZA DISTRICT, GILGIT-BALTISTAN, PAKISTAN

2021 ◽  
Vol 36 (3) ◽  
pp. 127-141
Author(s):  
Qasim ur Rehman ◽  
Waqas Ahmed ◽  
Muhammad Waseem ◽  
Sarfraz Khan ◽  
Asam Farid ◽  
...  
Keyword(s):  
Slip Rate ◽  
Bottom Layer ◽  
Earthquake Activity ◽  
Earthquake Hazards ◽  
Ground Acceleration ◽  
Non Invasive ◽  
Unconsolidated Material ◽  
Geophysical Investigations ◽  
Ground Penetrating ◽  
Gilgit Baltistan

The Mayoon landslide in the Hunza District is a slowly developed, non-catastrophic landslide that has gained its importance in the last few years after its rapid activation and fast slip rate. The area is characterized by high earthquake hazards (zone 3 with a peak ground acceleration value of 2.4–3.2 m/s2) by the Building Code of Pakistan due to frequent earth quakes. The past high earthquake activity in the area has displaced the foliated rocks towards the south and is responsible for opening the bedrock joints. The head and body of the landslide are covered by unconsolidated material and have fractures of varying lengths and widths. The non-invasive geophysical techniques, including Ground Penetrating Radar (GPR) and Electrical Resistivity Soundings (ERS), are deployed to evaluate the Mayoon landslide subsurface. The subsurface is interpreted into a two-layer model. Bright reflectors and highly variable resistivity characterize the top layer (Layer-1). This layer is associated with a loose, highly heterogeneous, fragmented material deposited under glacial settings over the existing bedrock. Hyperbolic reflections and intermediate resistivity characterize the bottom layer (Layer-2). This layer is associated with foliated metamorphic bedrock. The hyperbolic reflections show faults/fractures within the bedrock. The extension of these fractures/faults with depth is uncertain due to decay in the GPR signal with depth. The intermediate resistivity shows the bedrock is weathered and foliated. Reflections within Layer-1 have disrupted directly above the fractures/faults suggesting a possible movement. A bright reflection between the two layers highlights the presence of the debonded surface. Loose material within Layer-1 coupled with debonding possesses a significant hazard to generate a landslide under unfavourable conditions, such as an intense rainstorm or earthquake activity.

Formation Mechanism Analysis of Shear‐Induced Microgel Filaments during Microfluidic Gelation

2020 ◽  
pp. 2000586
Author(s):  
Shuhei Fukushima ◽  
Yuriko Takayama ◽  
Eri Nasuno ◽  
Yasuko Yanagida ◽  
Norihiro Kato
Keyword(s):  
Formation Mechanism ◽  
Mechanism Analysis

Models of Subsidence Sinkhole in Soils around Reservoirs

2014 ◽  
Vol 1065-1069 ◽  
pp. 575-579 ◽  
Author(s):  
Fu Wei Jiang ◽  
Ming Tang Lei ◽  
Jian Ling Dai ◽  
Long Jia ◽  
Yuan Bin Wu ◽  
...  
Keyword(s):  
Surface Water ◽  
Water Level ◽  
Formation Mechanism ◽  
Groundwater Level ◽  
General Mechanism ◽  
Karst Region ◽  
Groundwater Dynamic

The paper represents the models of subsidence sinkhole in soils around reservoirs in karst region. There are three essential conditions of the formation, such as cavity-fissure, overlying soils and groundwater dynamic. It leads to subsidence sinkhole based on three conditions when reservoirs change the underground hydrodynamics with regulating water. With the change of the surface water level controlled by reservoirs, the groundwater level alters, meaning to break the initial balance of sinkhole formation mechanism. Five models are established to describe the general mechanism change of groundwater hydrodynamic in this paper.

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