2020 Vol. 31 No. 5
Abstract：
The prediction of landslide disaster area has always been one of the difficulties in landslide research. The loess landslides in South Jingyang plateau were chosen to establish model of disaster area prediction, by electing height, volume, source area length and width of landslide as the influencing factors, which based on the bat algorithm to optimize calculation for least squares support vector machine in the regularization parameters (γ and σ2). In the meantime, they are compared with mutiple linear regression model. The result shows that the model has better prediction accuracy and effect. It can be used as the basis for disaster prevention and reduction in the area.
The prediction of landslide disaster area has always been one of the difficulties in landslide research. The loess landslides in South Jingyang plateau were chosen to establish model of disaster area prediction, by electing height, volume, source area length and width of landslide as the influencing factors, which based on the bat algorithm to optimize calculation for least squares support vector machine in the regularization parameters (γ and σ2). In the meantime, they are compared with mutiple linear regression model. The result shows that the model has better prediction accuracy and effect. It can be used as the basis for disaster prevention and reduction in the area.
Abstract：
The large-scale soil-rock mixture landslide is a kind of landslide type influenced by many factors such as engineering geological conditions, precipitation and earthquake, it is of great significance to study the causes of landslides and control methods for disaster prevention and mitigation, and for safeguarding the safety of people's lives and property. Based on Jiangdingya Landslide in Zhouqu, the causes and stability of the landslide are analyzed in details by means of historical data investigation, field geological investigation and numerical simulation, the corresponding comprehensive treatment measures are put forward as well. The results show that the topography, loose soil-rock are the internal factors that cause the landslide, while the continuous rainfall and the river erosion on the front edge of the landslide are the external factors that decrease the landslide stability. Based on the analysis of the landslide causes, the deformation of the landslide is effectively controlled by improving the structure of anti-slide pile wall, taking the lead in the application of prefabricated frame support, combined with the slope crack treatment project and other comprehensive treatment measures.The comprehensive treatment measures of the landslide can provide reference for similar high slope engineering and large-scale soil-rock mixture landslide treatment.
The large-scale soil-rock mixture landslide is a kind of landslide type influenced by many factors such as engineering geological conditions, precipitation and earthquake, it is of great significance to study the causes of landslides and control methods for disaster prevention and mitigation, and for safeguarding the safety of people's lives and property. Based on Jiangdingya Landslide in Zhouqu, the causes and stability of the landslide are analyzed in details by means of historical data investigation, field geological investigation and numerical simulation, the corresponding comprehensive treatment measures are put forward as well. The results show that the topography, loose soil-rock are the internal factors that cause the landslide, while the continuous rainfall and the river erosion on the front edge of the landslide are the external factors that decrease the landslide stability. Based on the analysis of the landslide causes, the deformation of the landslide is effectively controlled by improving the structure of anti-slide pile wall, taking the lead in the application of prefabricated frame support, combined with the slope crack treatment project and other comprehensive treatment measures.The comprehensive treatment measures of the landslide can provide reference for similar high slope engineering and large-scale soil-rock mixture landslide treatment.
2020, 31(5): 15-21.
DOI: 10.16031/j.cnki.issn.1003-8035.2020.05.03
Abstract：
Landslide formation, evolution and resurrection have been a hot topic in the field of landslide disaster prevention and mitigation. In the paper, based on analysis of the geological environment background and field survey, remote sensing interpretation, and experimental testing of large-scale landslides in the Jianzha Basin on the upper Yellow River, then taking the Simencun Landslide on the southern bank of the Yellow River in the basin as an example, the deformation process, characteristics of the landslide slip zone soil and accumulated body are discussed, the landslide formation process are reduction and reactive factors determined. Finally, some suggestions for the development and utilization of landslide deposits in the upper reaches of the Yellow River are put forward. It is believed that:(1) The landslide that was the old landslide occurred before 2005, which reactivated by the river-side erosion and artificial irrigation in spring 2018.(2) Comprehensive management of landslides should be combined with land remediation and appropriate irrigation methods should be selected, which is of great significance for landslide disaster prevention and mitigation and landslide body development and utilization in the upper reaches of the Yellow River on the northeastern part of the Tibetan Plateau.
Landslide formation, evolution and resurrection have been a hot topic in the field of landslide disaster prevention and mitigation. In the paper, based on analysis of the geological environment background and field survey, remote sensing interpretation, and experimental testing of large-scale landslides in the Jianzha Basin on the upper Yellow River, then taking the Simencun Landslide on the southern bank of the Yellow River in the basin as an example, the deformation process, characteristics of the landslide slip zone soil and accumulated body are discussed, the landslide formation process are reduction and reactive factors determined. Finally, some suggestions for the development and utilization of landslide deposits in the upper reaches of the Yellow River are put forward. It is believed that:(1) The landslide that was the old landslide occurred before 2005, which reactivated by the river-side erosion and artificial irrigation in spring 2018.(2) Comprehensive management of landslides should be combined with land remediation and appropriate irrigation methods should be selected, which is of great significance for landslide disaster prevention and mitigation and landslide body development and utilization in the upper reaches of the Yellow River on the northeastern part of the Tibetan Plateau.
2020, 31(5): 22-31.
DOI: 10.16031/j.cnki.issn.1003-8035.2020.05.04
Abstract：
It is an important task to predict and prevent debris flow and its impacted areas in advance. In this paper, RS and GIS technology were adopted to predict the potential debris flow. Taking advantage of the spatial resolution of domestic high-resolution images, using NNDiffuse and Gram-Schmidt methods to realize the fusion of remote sensing images into research data, combining with support vector machine (SVM) and dynamic clustering based on soil brightness index (ISODATA), the natural surface coverage and human impact area of debris flow formation region are identified and extracted, and then the formation region of debris flow is predicted by using the spatial and attribute relationship of hidden gully and catchment. The experiment shows that different fusion methods will affect the result of debris flow extraction. NNDiffuse fusion method has the best overall effect in this paper; SVM method has the best effect, the prior knowledge has the significance in the prediction of forming region, ISODATA method without prior knowledge has better performance in the identification and prediction of debris flow, there is potential application prospect in the future.
It is an important task to predict and prevent debris flow and its impacted areas in advance. In this paper, RS and GIS technology were adopted to predict the potential debris flow. Taking advantage of the spatial resolution of domestic high-resolution images, using NNDiffuse and Gram-Schmidt methods to realize the fusion of remote sensing images into research data, combining with support vector machine (SVM) and dynamic clustering based on soil brightness index (ISODATA), the natural surface coverage and human impact area of debris flow formation region are identified and extracted, and then the formation region of debris flow is predicted by using the spatial and attribute relationship of hidden gully and catchment. The experiment shows that different fusion methods will affect the result of debris flow extraction. NNDiffuse fusion method has the best overall effect in this paper; SVM method has the best effect, the prior knowledge has the significance in the prediction of forming region, ISODATA method without prior knowledge has better performance in the identification and prediction of debris flow, there is potential application prospect in the future.
Abstract：
Debris flow is a common geological hazard in mountainous areas. In order to quantitatively study the sensitivity of disaster-causing factors of debris flow and determine the weight coefficient of each hazard factors. The field investigation, mathematical statistics and analytic hierarchy process were used to study qualitatively and quantitative weights of hazard-causing factors in Longxi River Basin. The results show that:(1) the qualitative analysis between the occurrence of debris flow disasters and the susceptibility factors of hazards are as follows:the watershed area is less than 1 km2, the height difference is within 200 to 400 m, the distance from the fault is 0 to 2 km, and the slope of the slope is 30°~50°, the lithology is sandstone, the vertical ratio drops between 400‰ to 600‰, etc., the occurrence of debris flow disasters is well relevance to its main disaster-causing.(2) Four primary factors, including historical factor, topographic factor, geological factor and rainfall factor, as well as 14 secondary factors, such as watershed area, elevation, relative elevation difference, longitudinal slope ratio and stratigraphic lithology, are selected to establish the analytic hierarchy process model and the calculation judgment matrix. Obtains the weight value of disaster-causing factors on debris flow occurrence, which indicates that the four factors of rainfall, watershed area, stratigraphic lithology, and aspect ratio are the most sensitive to debris flow occurrence. This conclusion provides some data reference significance for the susceptibility, risk, and risk assessment of debris flow in the region.
Debris flow is a common geological hazard in mountainous areas. In order to quantitatively study the sensitivity of disaster-causing factors of debris flow and determine the weight coefficient of each hazard factors. The field investigation, mathematical statistics and analytic hierarchy process were used to study qualitatively and quantitative weights of hazard-causing factors in Longxi River Basin. The results show that:(1) the qualitative analysis between the occurrence of debris flow disasters and the susceptibility factors of hazards are as follows:the watershed area is less than 1 km2, the height difference is within 200 to 400 m, the distance from the fault is 0 to 2 km, and the slope of the slope is 30°~50°, the lithology is sandstone, the vertical ratio drops between 400‰ to 600‰, etc., the occurrence of debris flow disasters is well relevance to its main disaster-causing.(2) Four primary factors, including historical factor, topographic factor, geological factor and rainfall factor, as well as 14 secondary factors, such as watershed area, elevation, relative elevation difference, longitudinal slope ratio and stratigraphic lithology, are selected to establish the analytic hierarchy process model and the calculation judgment matrix. Obtains the weight value of disaster-causing factors on debris flow occurrence, which indicates that the four factors of rainfall, watershed area, stratigraphic lithology, and aspect ratio are the most sensitive to debris flow occurrence. This conclusion provides some data reference significance for the susceptibility, risk, and risk assessment of debris flow in the region.
2020, 31(5): 40-47.
DOI: 10.16031/j.cnki.issn.1003-8035.2020.05.06
Abstract：
In order to study the influence of excavation and house building on slope stablity, this paper analyzes the distribution and disaster models of geological disasters in the area of Luniao Town, Yuhang District, Zhejiang Province, and generalizes four types of slope models. The finite element limit equilibrium method is used to simulate the variation of stress, strain distribution and safety factor after the slope excavation, and then the threshold value of the excavation footage at the time of instability can be obtained through fitting the relationship between slope excavation footage and slope safety factor by the function curve. The result shows that:(1) Under natural conditiond the potential instability zone of the slope is located at the slope crest, and the probability of instability near the slope is higher than the other part of the slope. (2) When the slope is excavated, the slope and the excavation footage will jointly affect the slope stability, and the effect of the slope is greater than the excavation footage. (3) The error analysis shows that the threshold error of the slope with slope less than 20° is larger, and the threshold error of the slope with slope greater than 20° is smaller.
In order to study the influence of excavation and house building on slope stablity, this paper analyzes the distribution and disaster models of geological disasters in the area of Luniao Town, Yuhang District, Zhejiang Province, and generalizes four types of slope models. The finite element limit equilibrium method is used to simulate the variation of stress, strain distribution and safety factor after the slope excavation, and then the threshold value of the excavation footage at the time of instability can be obtained through fitting the relationship between slope excavation footage and slope safety factor by the function curve. The result shows that:(1) Under natural conditiond the potential instability zone of the slope is located at the slope crest, and the probability of instability near the slope is higher than the other part of the slope. (2) When the slope is excavated, the slope and the excavation footage will jointly affect the slope stability, and the effect of the slope is greater than the excavation footage. (3) The error analysis shows that the threshold error of the slope with slope less than 20° is larger, and the threshold error of the slope with slope greater than 20° is smaller.
Abstract：
Boyang town from Tongdao County is located in the prone area of geological disasters in Tongdao County. It is also one of the towns with the largest number of potential geological hazards and the largest number of threats. On the basis of analyzing the development characteristics of geological disasters in this area, taking Loutuan Landslide as the research object, this paper analyzes the spatial form, material composition and deformation characteristics of the landslide, adopts the limit equilibrium method, selects the broken line sliding model, calculates its stability under two different working conditions, and finally evaluates the stability of the landslide. It is concluded that under condition 1, it is basically stable, and under condition 2, it is under stable unstable. It is proposed that the measures for the treatment of Loutuan landslide include anti slide pile engineering, surface water interception and drainage engineering and slope ecological engineering. The research results will provide basis and reference for the treatment of this landslide.
Boyang town from Tongdao County is located in the prone area of geological disasters in Tongdao County. It is also one of the towns with the largest number of potential geological hazards and the largest number of threats. On the basis of analyzing the development characteristics of geological disasters in this area, taking Loutuan Landslide as the research object, this paper analyzes the spatial form, material composition and deformation characteristics of the landslide, adopts the limit equilibrium method, selects the broken line sliding model, calculates its stability under two different working conditions, and finally evaluates the stability of the landslide. It is concluded that under condition 1, it is basically stable, and under condition 2, it is under stable unstable. It is proposed that the measures for the treatment of Loutuan landslide include anti slide pile engineering, surface water interception and drainage engineering and slope ecological engineering. The research results will provide basis and reference for the treatment of this landslide.
Abstract：
Karst ground collapse in the study area are serious, the geological environment conditions are extremely complicated, the thickness of the Quaternary cover soil layer is large, the silty clay layer is developed at the bottom, and the hidden bedrock is the Hutian group limestone, caves and fault fracture zones are developed. The size of a single cave is usually very large, and the connectivity between the caves are good. The karst ground subsidence occurred with the disturbance of the silty clay layer or the sand soil layer and the formation of the soil hole. According to the characteristics of the double layer structure of the overlying layer in the studying area, the ground subsidence and the development of the soil hole could be divided into the sub-structure collapse mode of "under-adhesive sand" and the multi-structure collapse mode of "under-adhesive sand and soft soil". The collapse mechanism of karst collapse in subsidence area is mainly mechanical penetration, and the collapse development has experienced four stages. It is suggested that underground construction activities and pumping and arranging groundwater in a certain area in the exploration area is inappropriate. So as to avoid changes in groundwater dynamic conditions and reoccurrence of karst ground collapse.
Karst ground collapse in the study area are serious, the geological environment conditions are extremely complicated, the thickness of the Quaternary cover soil layer is large, the silty clay layer is developed at the bottom, and the hidden bedrock is the Hutian group limestone, caves and fault fracture zones are developed. The size of a single cave is usually very large, and the connectivity between the caves are good. The karst ground subsidence occurred with the disturbance of the silty clay layer or the sand soil layer and the formation of the soil hole. According to the characteristics of the double layer structure of the overlying layer in the studying area, the ground subsidence and the development of the soil hole could be divided into the sub-structure collapse mode of "under-adhesive sand" and the multi-structure collapse mode of "under-adhesive sand and soft soil". The collapse mechanism of karst collapse in subsidence area is mainly mechanical penetration, and the collapse development has experienced four stages. It is suggested that underground construction activities and pumping and arranging groundwater in a certain area in the exploration area is inappropriate. So as to avoid changes in groundwater dynamic conditions and reoccurrence of karst ground collapse.
Abstract：
Early warning of rock mass failure has always been an important research subject of mining disaster prevention. To improve the accuracy and reliability of early warning on rock mass failure, a comprehensive early warning method is proposed in this paper based on the Cusp catastrophe theory and D-S fusion evidence theory.Firstly, two independent early warning criteria were obtained by establishing the Cusp catastrophe analysis model and the D-S fusion evidence model. The following step was to form a comprehensive early warning criterion with two former criteria on the basis of risk matrix. Finally, the warning effect of the three warning methods mentioned above was tested by actual microseism data in the mine.The results show that:the cusp catastrophe model is less effective for early warning of rock mass failure and the D-S fusion evidence model is less robust, while the comprehensive early warning model has a higher accuracy and a better robustness.The accuracy and reliability of the early warning for rock mass failure is significantly improved.
Early warning of rock mass failure has always been an important research subject of mining disaster prevention. To improve the accuracy and reliability of early warning on rock mass failure, a comprehensive early warning method is proposed in this paper based on the Cusp catastrophe theory and D-S fusion evidence theory.Firstly, two independent early warning criteria were obtained by establishing the Cusp catastrophe analysis model and the D-S fusion evidence model. The following step was to form a comprehensive early warning criterion with two former criteria on the basis of risk matrix. Finally, the warning effect of the three warning methods mentioned above was tested by actual microseism data in the mine.The results show that:the cusp catastrophe model is less effective for early warning of rock mass failure and the D-S fusion evidence model is less robust, while the comprehensive early warning model has a higher accuracy and a better robustness.The accuracy and reliability of the early warning for rock mass failure is significantly improved.
Abstract：
A large number of geological disasters caused by the Jiuzhaigou 7.0 earthquake caused great damage to the landscape, ecology and infrastructure in Jiuzhaigou scenic area. The disasters along the scenic roads were frequent, the roads were severely damaged, and many were interrupted. Due to the extremely complicated terrain and geological conditions, the road section between the Wuhuahai and Xiongmaohai is most damaged. Reconstruction and other engineering activities in ecologically sensitive areas such as Jiuzhaigou can not meet the needs of the evaluation of engineering schemes by geological disaster assessment alone. At the same time, the interaction between engineering activities, geological disasters and ecology must be considered. This article for the first time combined with the geological disaster risk assessment, established the ecological risk assessment criteria for ecologically sensitive areas. Based on both of the disaster assessment and ecological risk assessment, the road restoration and reconstruction plan of Laohuzui road section in Jiuzhaigou was evaluated and demonstrated. The road restoration and reconstruction plan was finalized.
A large number of geological disasters caused by the Jiuzhaigou 7.0 earthquake caused great damage to the landscape, ecology and infrastructure in Jiuzhaigou scenic area. The disasters along the scenic roads were frequent, the roads were severely damaged, and many were interrupted. Due to the extremely complicated terrain and geological conditions, the road section between the Wuhuahai and Xiongmaohai is most damaged. Reconstruction and other engineering activities in ecologically sensitive areas such as Jiuzhaigou can not meet the needs of the evaluation of engineering schemes by geological disaster assessment alone. At the same time, the interaction between engineering activities, geological disasters and ecology must be considered. This article for the first time combined with the geological disaster risk assessment, established the ecological risk assessment criteria for ecologically sensitive areas. Based on both of the disaster assessment and ecological risk assessment, the road restoration and reconstruction plan of Laohuzui road section in Jiuzhaigou was evaluated and demonstrated. The road restoration and reconstruction plan was finalized.
2020, 31(5): 79-87.
DOI: 10.16031/j.cnki.issn.1003-8035.2020.05.11
Abstract：
In order to determine the seismic active earth pressure on cantilever retaining walls, five potential failure modes of the backfill are provided considering the possible locations of the assumed planar back of the walls. Based on the potential failure mechanisms, formulas of the earth pressure on the planar back are derived in light of the quasi-static method and upper bound theory of the kinematical limit analysis, which can reflect various influence factors including properties of the backfill, dip angle of the filling surface, length of base slab with heel, wall height, as well as horizontal and vertical seismic impact factors. Most of the influence factors are nonlinearly linked with the earth pressure except for cohesion of the backfill and vertical seismic impact factor. Analysis results of some examples show that overturning and translating factors of safety of the wall determined via the earth pressure by the proposed method are both slightly higher than those by the Mononobe-Okabe mehtod in most practical cases, and the analysis model of the assumed wallback starting exactly from the bottom of the wall heel is relatively marginally unsafe if there is the second failure surface in the backfill. The seismic active earth pressure obtained by the failure mode with vertically assumed wall back is relatively minimum, but the corresponding two factors of safety are not certainly maximum.
In order to determine the seismic active earth pressure on cantilever retaining walls, five potential failure modes of the backfill are provided considering the possible locations of the assumed planar back of the walls. Based on the potential failure mechanisms, formulas of the earth pressure on the planar back are derived in light of the quasi-static method and upper bound theory of the kinematical limit analysis, which can reflect various influence factors including properties of the backfill, dip angle of the filling surface, length of base slab with heel, wall height, as well as horizontal and vertical seismic impact factors. Most of the influence factors are nonlinearly linked with the earth pressure except for cohesion of the backfill and vertical seismic impact factor. Analysis results of some examples show that overturning and translating factors of safety of the wall determined via the earth pressure by the proposed method are both slightly higher than those by the Mononobe-Okabe mehtod in most practical cases, and the analysis model of the assumed wallback starting exactly from the bottom of the wall heel is relatively marginally unsafe if there is the second failure surface in the backfill. The seismic active earth pressure obtained by the failure mode with vertically assumed wall back is relatively minimum, but the corresponding two factors of safety are not certainly maximum.
Abstract：
The quantity and scale of construction waste slopes increase rapidly with the development of urban construction, causing much concern on the prevention and control of construction waste slopes. The construction waste slope engineering is affected by artificial layering and the uncertainty of properties of the layered soil. To handle this problem, a multi-objective optimization design method of sliding resistant components in construction waste slopes is proposed. With this method, pre-construction of sliding resistant components at the bottom of the landfill is adopted. Consider the influence of different reinforcement strength on the estimated failure loss of construction waste slopes, the failure loss, stable security and the construction cost of construction waste slopes are selected as design objects. Based on the multi-objective optimization theory, the Pareto front is determined. Through calculating the knee point on this Pareto front, an optimal design of the sliding resistant components is derived. The method proposed herein is applied in a construction waste slope in Shenzhen and the result indicates that two groups of the sliding resistant components with 3 m and the 5 m are pre-constructed at the front of the slope to reinforce the landfill. With adopting the presented design, the stability, failure loss and reinforcement cost of the slope can be optimally balanced.
The quantity and scale of construction waste slopes increase rapidly with the development of urban construction, causing much concern on the prevention and control of construction waste slopes. The construction waste slope engineering is affected by artificial layering and the uncertainty of properties of the layered soil. To handle this problem, a multi-objective optimization design method of sliding resistant components in construction waste slopes is proposed. With this method, pre-construction of sliding resistant components at the bottom of the landfill is adopted. Consider the influence of different reinforcement strength on the estimated failure loss of construction waste slopes, the failure loss, stable security and the construction cost of construction waste slopes are selected as design objects. Based on the multi-objective optimization theory, the Pareto front is determined. Through calculating the knee point on this Pareto front, an optimal design of the sliding resistant components is derived. The method proposed herein is applied in a construction waste slope in Shenzhen and the result indicates that two groups of the sliding resistant components with 3 m and the 5 m are pre-constructed at the front of the slope to reinforce the landfill. With adopting the presented design, the stability, failure loss and reinforcement cost of the slope can be optimally balanced.
Abstract：
In order to further improve the safety of the shallow overburden and eccentric pressure section of the tunnel portal during earthquake, based on a railway tunnel portal section project, the seismic effect of two kinds of surrounding rock grouting anti-seismic measures were studied by using the finite difference numerical calculation software, and the influence of two kinds of anti-seismic measures of contact grouting and interval grouting on the displacement and internal force of the tunnel lining structure is compared and analyzed. After the contact grouting is adopted in the surrounding rock, the results show that the lateral and longitudinal displacements of the secondary lining structure are reduced by 86.7% and 38.1% respectively, the axial force and bending moment are reduced by 45.12% and 64.20% on average, and the minimum safety factor is increased by 61.36% on average; after interval grouting, the lateral and longitudinal displacements of the secondary lining structure are reduced by 49.3% and 23.8% respectively, the axial force and bending moment are reduced by 39.42% and 44.90% on average, and the minimum safety factor is increased by 43.11% on average. The anti-seismic effect of contact grouting is better than that of interval grouting. The research results can provide reference for the development of anti-seismic technology of tunnel portal section.
In order to further improve the safety of the shallow overburden and eccentric pressure section of the tunnel portal during earthquake, based on a railway tunnel portal section project, the seismic effect of two kinds of surrounding rock grouting anti-seismic measures were studied by using the finite difference numerical calculation software, and the influence of two kinds of anti-seismic measures of contact grouting and interval grouting on the displacement and internal force of the tunnel lining structure is compared and analyzed. After the contact grouting is adopted in the surrounding rock, the results show that the lateral and longitudinal displacements of the secondary lining structure are reduced by 86.7% and 38.1% respectively, the axial force and bending moment are reduced by 45.12% and 64.20% on average, and the minimum safety factor is increased by 61.36% on average; after interval grouting, the lateral and longitudinal displacements of the secondary lining structure are reduced by 49.3% and 23.8% respectively, the axial force and bending moment are reduced by 39.42% and 44.90% on average, and the minimum safety factor is increased by 43.11% on average. The anti-seismic effect of contact grouting is better than that of interval grouting. The research results can provide reference for the development of anti-seismic technology of tunnel portal section.
Abstract：
Taking the construction of ZKxx3 hole in the first stage of grouting reconstruction of no. 2 coal-ornite aquifer in north well 9400 dongpang mine as an example, this paper introduces in detail the construction design, drilling technology and main technical measures of directional drilling for horizontal branch hole. Practice proved that the directional drilling technology as much as possible to probe into the ordovician limestone aquifer fault and collapse column structure of the area of the water channel and rich water, advance grouting filling the upper ordovician limestone dissolution gaps and cracks, jig faults and tectonic weak section, expand the reinforcement area, to realize the local management to the ground area management by underground coal floor Mr Grey water disasters, from the advanced detection to dig governance before, met the area ahead of the prevention and control of water disasters objectives in time and space, has achieved remarkable economic and environmental effects.
Taking the construction of ZKxx3 hole in the first stage of grouting reconstruction of no. 2 coal-ornite aquifer in north well 9400 dongpang mine as an example, this paper introduces in detail the construction design, drilling technology and main technical measures of directional drilling for horizontal branch hole. Practice proved that the directional drilling technology as much as possible to probe into the ordovician limestone aquifer fault and collapse column structure of the area of the water channel and rich water, advance grouting filling the upper ordovician limestone dissolution gaps and cracks, jig faults and tectonic weak section, expand the reinforcement area, to realize the local management to the ground area management by underground coal floor Mr Grey water disasters, from the advanced detection to dig governance before, met the area ahead of the prevention and control of water disasters objectives in time and space, has achieved remarkable economic and environmental effects.
2020, 31(5): 112-116.
DOI: 10.16031/j.cnki.issn.1003-8035.2020.05.15
Abstract：
Due to the special geological environment conditions, the development of geological disasters in our province, coupled with economic growth, urban expansion, rainfall increase and other factors in recent years, the number of geological disasters and economic losses are on the rise, so geological disaster prevention and control is particularly necessary. In order to fully understand the relationship between geological disaster prevention investment and social economic development, this paper analyzes and studies the current situation of geological disaster, geological disaster prevention and control investment and economic development data in recent ten years, establishes the overall income function under the fixed economic investment, and holds that although the geological disaster prevention and control effect in Qinghai Province is good in recent years, from the overall point of view, the geological disaster prevention investment in Qinghai Province is low and fails to reach the best profit point. Therefore, the relevant departments should pay attention to the prevention and control of geological disasters while taking into account the economic development. With the economic growth, appropriate adjustment of prevention input can not only effectively control the loss of geological disasters, but also guarantee other social benefits.
Due to the special geological environment conditions, the development of geological disasters in our province, coupled with economic growth, urban expansion, rainfall increase and other factors in recent years, the number of geological disasters and economic losses are on the rise, so geological disaster prevention and control is particularly necessary. In order to fully understand the relationship between geological disaster prevention investment and social economic development, this paper analyzes and studies the current situation of geological disaster, geological disaster prevention and control investment and economic development data in recent ten years, establishes the overall income function under the fixed economic investment, and holds that although the geological disaster prevention and control effect in Qinghai Province is good in recent years, from the overall point of view, the geological disaster prevention investment in Qinghai Province is low and fails to reach the best profit point. Therefore, the relevant departments should pay attention to the prevention and control of geological disasters while taking into account the economic development. With the economic growth, appropriate adjustment of prevention input can not only effectively control the loss of geological disasters, but also guarantee other social benefits.
Abstract：
This paper analyzes the storage and access requirements of massive spatio-temporal monitoring data in the Guizhou Povince gelogical disaster monitoring equipment operation mintenance sheduling platform, and proposes a solution to solve the problems of storage capacity and access efficiency in traditional database when dealing with massive operation and maintenance scheduling data. Based on the design of time series database, the Guizhou Povince gelogical disaster monitoring equipment operation maintenance sheduling platform has been upgraded and reconstructed.
This paper analyzes the storage and access requirements of massive spatio-temporal monitoring data in the Guizhou Povince gelogical disaster monitoring equipment operation mintenance sheduling platform, and proposes a solution to solve the problems of storage capacity and access efficiency in traditional database when dealing with massive operation and maintenance scheduling data. Based on the design of time series database, the Guizhou Povince gelogical disaster monitoring equipment operation maintenance sheduling platform has been upgraded and reconstructed.
2020, 31(5): 123-132.
DOI: 10.16031/j.cnki.issn.1003-8035.2020.05.17
Abstract：
In-situ stress testing of eight boreholes by hydraulic fracturing was carried out at the active fault zone of Xianglushan Tunnel engineering area of water diversion project in central Yunnan. The results show that the horizontal tectonic stress plays a dominant role in engineering area. The stress regimes in Longpan-Qiaohou Fault and Lijiang-Jianchuan Fault area are of strike-slip faulting. The stress regimes in west branch and south segment of Heqing-Eryuan Fault area are strike-slip and reverse faulting, respectively. From the standpoint of stress accumulation, the measured maximum principal stresses at most test points of the three active faults within the detection range do not exceed the thresholds that cause the slipping instability of the fault. There is a difference between the dominant direction NNE-NE of the measured maximum horizontal principal stresses obtained by in-situ stress test and the NEE direction of the principal compressive stress of the current tectonic stress field obtained from the inversion of focal mechanismin this area, indicating that the measured in-situ stresses have been influenced to a certain extent by fault activities. Taking account of multiple index parameters of active fault deformation and mechanical properties, the Fuzzy-Grey comprehensive evaluation of the influence of active faults shows that the influence of Longpan-Qiaohou fault on tunnel engineering is weak and Lijiang-Jianchuan Fault is the strongest, which should arouse more attention.
In-situ stress testing of eight boreholes by hydraulic fracturing was carried out at the active fault zone of Xianglushan Tunnel engineering area of water diversion project in central Yunnan. The results show that the horizontal tectonic stress plays a dominant role in engineering area. The stress regimes in Longpan-Qiaohou Fault and Lijiang-Jianchuan Fault area are of strike-slip faulting. The stress regimes in west branch and south segment of Heqing-Eryuan Fault area are strike-slip and reverse faulting, respectively. From the standpoint of stress accumulation, the measured maximum principal stresses at most test points of the three active faults within the detection range do not exceed the thresholds that cause the slipping instability of the fault. There is a difference between the dominant direction NNE-NE of the measured maximum horizontal principal stresses obtained by in-situ stress test and the NEE direction of the principal compressive stress of the current tectonic stress field obtained from the inversion of focal mechanismin this area, indicating that the measured in-situ stresses have been influenced to a certain extent by fault activities. Taking account of multiple index parameters of active fault deformation and mechanical properties, the Fuzzy-Grey comprehensive evaluation of the influence of active faults shows that the influence of Longpan-Qiaohou fault on tunnel engineering is weak and Lijiang-Jianchuan Fault is the strongest, which should arouse more attention.
2020, 31(5): 133-140.
DOI: 10.16031/j.cnki.issn.1003-8035.2020.05.18
Abstract：
In order to study the influence of joints to the mechanical characteristics of rock mass and the evolution of instability damage, by using anchoring through joint rock PFC2D doing indoor shear test and numerical simulation method, studying the anchoring through joint rock mass under different joint angle shear performance of the mechanism of behaviour and failure mode, the result shows that:(1)with joint angle changing, it presents different failure modes through joint rock samples, and anchor through joint shear strength of rock mass and the shear displacement curve is not a linear growth, but a trend of "double hump".(2)During the shear test of the anchorage system, the contact azimuth angle of jointed surface particles changes in a certain extent, mainly in the vicinity of the anchor rod and the joint inclination angle.(3)During the shear test the anchorage system, it will generate cracks in the anchorage system due to the fracture of the interparticle bonding bond. The fewer the number of cracks are, the higher the shear strength is. The cracks include tensile crack and shear crack, and the number of tensile crack is much larger than the shear crack's.The results can be used to predict the actual failure mode and evaluate the stability of rock mass engineering.
In order to study the influence of joints to the mechanical characteristics of rock mass and the evolution of instability damage, by using anchoring through joint rock PFC2D doing indoor shear test and numerical simulation method, studying the anchoring through joint rock mass under different joint angle shear performance of the mechanism of behaviour and failure mode, the result shows that:(1)with joint angle changing, it presents different failure modes through joint rock samples, and anchor through joint shear strength of rock mass and the shear displacement curve is not a linear growth, but a trend of "double hump".(2)During the shear test of the anchorage system, the contact azimuth angle of jointed surface particles changes in a certain extent, mainly in the vicinity of the anchor rod and the joint inclination angle.(3)During the shear test the anchorage system, it will generate cracks in the anchorage system due to the fracture of the interparticle bonding bond. The fewer the number of cracks are, the higher the shear strength is. The cracks include tensile crack and shear crack, and the number of tensile crack is much larger than the shear crack's.The results can be used to predict the actual failure mode and evaluate the stability of rock mass engineering.
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