Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in ex...Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in extent. Furthermore, due to the different heights of mountains and the lengths of tunnels, the locations of the unfavorable geological sections cannot be fully determined before construction, which increases the risk of water inrush and mud gushing. Based on numerous cases of water inrush and mud gushing in railway tunnels, the paper tries to classify water inrush and mud gushing in railway tunnels in view of the conditions of the surrounding rocks and meteorological factors associated with tunnel excavation. In addition, the causes of water inrush and mud gushing in combination of macroand micromechanisms are summarized, and site-specifc treatment method is put forward. The treatment methods include choosing a method of advance geological forecast according to risk degrees of different sections in the tunnel, determining the items of predictions, and choosing the appropriate methods, i.e. draining-oriented method, blocking-oriented method or draining-and-blocking method. The treatment technologies of railway water inrush and mud gushing are also summarized, including energy relief and pressure relief technology, advance grouting technology, and advance jet grouting technology associated with their key technical features and applicable conditions. The results in terms of treatment methods can provide reference to the prevention and treatment of tunnel water inrush and mud gushing.展开更多
This paper presents a case study of water inrush and mud burst occurring in a migmatite tunnel to study its formation mechanisms. The geological investigation and mineralogical analysis showed that water inrush and mu...This paper presents a case study of water inrush and mud burst occurring in a migmatite tunnel to study its formation mechanisms. The geological investigation and mineralogical analysis showed that water inrush and mud burst in the migmatite was closely related to the component of the host rock. High content of soluble minerals,e.g.,calcite and dolomite,would make the migmatite rock prone to be fragmentized,isintegrated and eventually form different sorts of connected or semi-connected veins. The field exploration revealed most cavities in the magmatite tunnel were eroded by groundwater and formed large interconnected networks. The two faults and the dike in the magmatite tunnel became the preferred paths and provided great convenience for plenty of precipitation and mud slurry. Due to high water pressure and blast disturbance,the cavities can soon connect each other as well as all sorts of veins,forming a complex ground channel for water inrush and mud burst. To estimate the potential occurrenceof water inrush and mud burst,the water bursting coefficient was employed. The results showed the water bursting coefficient of the magmatite tunnel was much bigger than the threshold values and it can be used to explain the accident of water inrush and mud burst occurring in the magmatite tunnel.展开更多
Mud and water inrush in tunnel is a common problem in the construction process. Nowadays, the research and classification on this are mostly focused on karst situations. According to the characteristics of the surroun...Mud and water inrush in tunnel is a common problem in the construction process. Nowadays, the research and classification on this are mostly focused on karst situations. According to the characteristics of the surrounding rock and damage forms of the tunnel in the studied area, the author analyzed the geological and structural characteristics of mud and water inrush in tunnel and obtained their construction type. Meanwhile, the advanced water detection under the complex geological conditions was studied by using induced polarization method, transient electromagnetic method and three-dimensional seismic method, it can be concluded that the water-rich fracture zone exists within the detection range with a risk of large mud and water inrush disaster. The concrete construction treatment measures are put forward:①cement-water glass binary slurry is selected as the material for ground and hole grouting, its advantage is that the gel time can be controlled, and it has certain grout ability in the strata with large permeability coeffcient, which is conducive to excavate construction immediately after grouting.②applying the mature retrograde grouting construction can reduce grouting time and improve the excavation efficiency.展开更多
With the rapid development of the transportation industry in China,the number and scale of tunnel construction are increasing.Tunneling through fault zones and other complex geological environments is becoming more an...With the rapid development of the transportation industry in China,the number and scale of tunnel construction are increasing.Tunneling through fault zones and other complex geological environments is becoming more and more common.In the construction of highway tunnels,due to the special geographical environment and complex geological conditions,mud and water inrush often occur in the tunnel.Water inrush disasters pose a major risk to the construction of highway tunnels and affect the normal construction of highway tunnels.This paper combines the engineering background of the tunnel mud and water inrush accidents,carries out evaluation on the accident treatment measures and the treatment efficiency,and summarizes the main concerns in the construction process and the technical guidelines for dealing with the tunnel mud and water inrush.展开更多
This paper presents a risk evaluation model of water and mud inrush for tunnel excavation in karst areas.The factors affecting the probabilities of water and mud inrush in karst tunnels are investigated to define the ...This paper presents a risk evaluation model of water and mud inrush for tunnel excavation in karst areas.The factors affecting the probabilities of water and mud inrush in karst tunnels are investigated to define the dangerousness of this geological disaster.The losses that are caused by water and mud inrush are taken into consideration to account for its harmfulness.Then a risk evaluation model based on the dangerousness-harmfulness evaluation indicator system is constructed,which is more convincing in comparison with the traditional methods.The catastrophe theory is used to evaluate the risk level of water and mud inrush and it has great advantage in handling problems involving discontinuous catastrophe processes.To validate the proposed approach,the Qiyueshan tunnel of Yichang-Wanzhou Railway is taken as an example in which four target segments are evaluated using the risk evaluation model.Finally,the evaluation results are compared with the excavation data,which shows that the risk levels predicted by the proposed approach are in good agreements with that observed in engineering.In conclusion,the catastrophe theory-based risk evaluation model is an efficient and effective approach for water and mud inrush in karst tunnels.展开更多
Phosphorus (P) transported in runoff from broiler production areas is a potential source for nutrient enrichment of local surface waters. Capturing nutrients prior to runoff leaving the production area could reduce th...Phosphorus (P) transported in runoff from broiler production areas is a potential source for nutrient enrichment of local surface waters. Capturing nutrients prior to runoff leaving the production area could reduce the risk of transport. Commercially available systems for nitrogen (N) and P removal from stormwater are available but too expensive for widespread adoption on small, privately owned farms. The P adsorption capacities and hydraulic conductivities of locally-sourced iron red mud (RM) and aluminum water treatment residual (WT) were determined for potential on-farm treatment use. The byproducts were air-dried and separated into ≤2-, ≤6-, and ≤12.5-mm particle size fractions. Saturated hydraulic conductivity (HC) was determined for each particle-size fraction and results evaluated for the material’s ability to transmit a 25-year, 30-min rainfall of 6.6 cm. While the HC of ≤6-mm particles of each byproduct did not differ (p > 0.05;4.1 and 4.6 cm·min<sup>-1</sup>), for ≤12.5-mm particles it was greater (p > 0.05) for WT than RM (15.4 and 8.0 cm·min<sup>-1</sup>, respectively). However, all byproduct size fractions transmitted flow sufficiently to accommodate the baseline storm. Phosphorous adsorption maxima of ≤2-mm fraction for RM and WT were 25 and 10 g·P·kg<sup>-1</sup>, respectively. Using a solution containing 6 mg·P·L<sup>-1</sup>, rep-resenting the measured runoff-P concentration from areas adjacent to poultry house ventilation fans, the ≤2-mm fraction of RM removed 98% of added P and WT 84%. The ≤6-mm fraction of RM and WT removed 56% and 57% of added P, respectively, while the ≤12.5-mm fraction adsorbed only 28% and 10%. Results indicate the potential use of low-cost RM and WT byproducts to sequester P in runoff prior to P leaving poultry farm production areas.展开更多
A common issue with filters designed to remove nutrients from runoff is their reduced effectiveness in high-flow conditions. To overcome this challenge, it was determined that nutrient removal from broiler-house fan d...A common issue with filters designed to remove nutrients from runoff is their reduced effectiveness in high-flow conditions. To overcome this challenge, it was determined that nutrient removal from broiler-house fan dust could be more effective if nutrient removal was conducted at the nutrient source. The objective of this study was to evaluate the effectiveness of containment trays (CTs) holding locally sourced by-products installed adjacent to broiler house fans at the University of Arkansas Savoy broiler production facility to capture nutrients released from dust during rainfall over four years (2013 to 2017). By-products used were locally sourced, iron-based red mud (RM) generated during the manufacture of steel belts for tires and alum-based drinking water treatment residual (WTR), where both materials have large phosphorus (P) sorption capacities. Four-year mean annual concentrations of dissolved P of through-flow from RM CTs were consistently below 0.7 mg·L-1 and below 1.6 mg·L-1 for WTR CT through-flow. This equated to an average 11- and 4-fold decrease for RM and WTR, relative to concentrations in runoff from same-sized plots adjacent to sidewall fans, demonstrating their potential to trap P at the source and decrease P runoff to nearby flowing waters. While there was no significant decline in RM or WTR effective-ness over the four-year study, further work needs to be conducted to determine the lifespan of CTs. Use of RM and WTR in CTs at poultry broiler production facilities, along with their subsequent land application, has the potential to reduce the amount of by-product materials that are currently landfilled.展开更多
为探究隧道穿越第三系半成岩富水段时引发的涌水突泥、冒顶等地质灾害机制,依托云南临清高速公路王家寨隧道,通过室内力学试验和模糊层次分析法,对第三系半成岩力学特性、作用机制及涌水突泥灾害风险进行分析。研究表明:1)王家寨隧道第...为探究隧道穿越第三系半成岩富水段时引发的涌水突泥、冒顶等地质灾害机制,依托云南临清高速公路王家寨隧道,通过室内力学试验和模糊层次分析法,对第三系半成岩力学特性、作用机制及涌水突泥灾害风险进行分析。研究表明:1)王家寨隧道第三系半成岩遇水软化特性明显,随着含水率增加其黏聚力先增后减,内摩擦角不断减小,含水率为18%时黏聚力与内摩擦角分别为12.53 k Pa和7.35°,围岩逐渐失稳。2)软弱的第三系半成岩、高地下水量及隧道开挖扰动为王家寨隧道第三系半成岩富水段发生涌水突泥灾害的主要影响因素。3)王家寨隧道第三系半成岩段可按工程地质条件、水文地质条件划分为A、B、C、D 4段,各段涌水突泥灾害风险由大到小排序为B段=C段>A段>D段,其中评估的A段涌泥量与实际涌泥量较为吻合。展开更多
文摘Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in extent. Furthermore, due to the different heights of mountains and the lengths of tunnels, the locations of the unfavorable geological sections cannot be fully determined before construction, which increases the risk of water inrush and mud gushing. Based on numerous cases of water inrush and mud gushing in railway tunnels, the paper tries to classify water inrush and mud gushing in railway tunnels in view of the conditions of the surrounding rocks and meteorological factors associated with tunnel excavation. In addition, the causes of water inrush and mud gushing in combination of macroand micromechanisms are summarized, and site-specifc treatment method is put forward. The treatment methods include choosing a method of advance geological forecast according to risk degrees of different sections in the tunnel, determining the items of predictions, and choosing the appropriate methods, i.e. draining-oriented method, blocking-oriented method or draining-and-blocking method. The treatment technologies of railway water inrush and mud gushing are also summarized, including energy relief and pressure relief technology, advance grouting technology, and advance jet grouting technology associated with their key technical features and applicable conditions. The results in terms of treatment methods can provide reference to the prevention and treatment of tunnel water inrush and mud gushing.
基金support of the National Natural Science Foundation of China (Grant Nos.51379007,41130742)the support of the Chinese Fundamental Research (973)Program through the Grant No.2013CB036006
文摘This paper presents a case study of water inrush and mud burst occurring in a migmatite tunnel to study its formation mechanisms. The geological investigation and mineralogical analysis showed that water inrush and mud burst in the migmatite was closely related to the component of the host rock. High content of soluble minerals,e.g.,calcite and dolomite,would make the migmatite rock prone to be fragmentized,isintegrated and eventually form different sorts of connected or semi-connected veins. The field exploration revealed most cavities in the magmatite tunnel were eroded by groundwater and formed large interconnected networks. The two faults and the dike in the magmatite tunnel became the preferred paths and provided great convenience for plenty of precipitation and mud slurry. Due to high water pressure and blast disturbance,the cavities can soon connect each other as well as all sorts of veins,forming a complex ground channel for water inrush and mud burst. To estimate the potential occurrenceof water inrush and mud burst,the water bursting coefficient was employed. The results showed the water bursting coefficient of the magmatite tunnel was much bigger than the threshold values and it can be used to explain the accident of water inrush and mud burst occurring in the magmatite tunnel.
基金Supported by Project of China Railway 21 Bureau Group Co.,Ltd.(No.XJD20170815007)
文摘Mud and water inrush in tunnel is a common problem in the construction process. Nowadays, the research and classification on this are mostly focused on karst situations. According to the characteristics of the surrounding rock and damage forms of the tunnel in the studied area, the author analyzed the geological and structural characteristics of mud and water inrush in tunnel and obtained their construction type. Meanwhile, the advanced water detection under the complex geological conditions was studied by using induced polarization method, transient electromagnetic method and three-dimensional seismic method, it can be concluded that the water-rich fracture zone exists within the detection range with a risk of large mud and water inrush disaster. The concrete construction treatment measures are put forward:①cement-water glass binary slurry is selected as the material for ground and hole grouting, its advantage is that the gel time can be controlled, and it has certain grout ability in the strata with large permeability coeffcient, which is conducive to excavate construction immediately after grouting.②applying the mature retrograde grouting construction can reduce grouting time and improve the excavation efficiency.
文摘With the rapid development of the transportation industry in China,the number and scale of tunnel construction are increasing.Tunneling through fault zones and other complex geological environments is becoming more and more common.In the construction of highway tunnels,due to the special geographical environment and complex geological conditions,mud and water inrush often occur in the tunnel.Water inrush disasters pose a major risk to the construction of highway tunnels and affect the normal construction of highway tunnels.This paper combines the engineering background of the tunnel mud and water inrush accidents,carries out evaluation on the accident treatment measures and the treatment efficiency,and summarizes the main concerns in the construction process and the technical guidelines for dealing with the tunnel mud and water inrush.
基金Project(51378510)supported by National Natural Science Foundation of China。
文摘This paper presents a risk evaluation model of water and mud inrush for tunnel excavation in karst areas.The factors affecting the probabilities of water and mud inrush in karst tunnels are investigated to define the dangerousness of this geological disaster.The losses that are caused by water and mud inrush are taken into consideration to account for its harmfulness.Then a risk evaluation model based on the dangerousness-harmfulness evaluation indicator system is constructed,which is more convincing in comparison with the traditional methods.The catastrophe theory is used to evaluate the risk level of water and mud inrush and it has great advantage in handling problems involving discontinuous catastrophe processes.To validate the proposed approach,the Qiyueshan tunnel of Yichang-Wanzhou Railway is taken as an example in which four target segments are evaluated using the risk evaluation model.Finally,the evaluation results are compared with the excavation data,which shows that the risk levels predicted by the proposed approach are in good agreements with that observed in engineering.In conclusion,the catastrophe theory-based risk evaluation model is an efficient and effective approach for water and mud inrush in karst tunnels.
文摘Phosphorus (P) transported in runoff from broiler production areas is a potential source for nutrient enrichment of local surface waters. Capturing nutrients prior to runoff leaving the production area could reduce the risk of transport. Commercially available systems for nitrogen (N) and P removal from stormwater are available but too expensive for widespread adoption on small, privately owned farms. The P adsorption capacities and hydraulic conductivities of locally-sourced iron red mud (RM) and aluminum water treatment residual (WT) were determined for potential on-farm treatment use. The byproducts were air-dried and separated into ≤2-, ≤6-, and ≤12.5-mm particle size fractions. Saturated hydraulic conductivity (HC) was determined for each particle-size fraction and results evaluated for the material’s ability to transmit a 25-year, 30-min rainfall of 6.6 cm. While the HC of ≤6-mm particles of each byproduct did not differ (p > 0.05;4.1 and 4.6 cm·min<sup>-1</sup>), for ≤12.5-mm particles it was greater (p > 0.05) for WT than RM (15.4 and 8.0 cm·min<sup>-1</sup>, respectively). However, all byproduct size fractions transmitted flow sufficiently to accommodate the baseline storm. Phosphorous adsorption maxima of ≤2-mm fraction for RM and WT were 25 and 10 g·P·kg<sup>-1</sup>, respectively. Using a solution containing 6 mg·P·L<sup>-1</sup>, rep-resenting the measured runoff-P concentration from areas adjacent to poultry house ventilation fans, the ≤2-mm fraction of RM removed 98% of added P and WT 84%. The ≤6-mm fraction of RM and WT removed 56% and 57% of added P, respectively, while the ≤12.5-mm fraction adsorbed only 28% and 10%. Results indicate the potential use of low-cost RM and WT byproducts to sequester P in runoff prior to P leaving poultry farm production areas.
文摘A common issue with filters designed to remove nutrients from runoff is their reduced effectiveness in high-flow conditions. To overcome this challenge, it was determined that nutrient removal from broiler-house fan dust could be more effective if nutrient removal was conducted at the nutrient source. The objective of this study was to evaluate the effectiveness of containment trays (CTs) holding locally sourced by-products installed adjacent to broiler house fans at the University of Arkansas Savoy broiler production facility to capture nutrients released from dust during rainfall over four years (2013 to 2017). By-products used were locally sourced, iron-based red mud (RM) generated during the manufacture of steel belts for tires and alum-based drinking water treatment residual (WTR), where both materials have large phosphorus (P) sorption capacities. Four-year mean annual concentrations of dissolved P of through-flow from RM CTs were consistently below 0.7 mg·L-1 and below 1.6 mg·L-1 for WTR CT through-flow. This equated to an average 11- and 4-fold decrease for RM and WTR, relative to concentrations in runoff from same-sized plots adjacent to sidewall fans, demonstrating their potential to trap P at the source and decrease P runoff to nearby flowing waters. While there was no significant decline in RM or WTR effective-ness over the four-year study, further work needs to be conducted to determine the lifespan of CTs. Use of RM and WTR in CTs at poultry broiler production facilities, along with their subsequent land application, has the potential to reduce the amount of by-product materials that are currently landfilled.
文摘为探究隧道穿越第三系半成岩富水段时引发的涌水突泥、冒顶等地质灾害机制,依托云南临清高速公路王家寨隧道,通过室内力学试验和模糊层次分析法,对第三系半成岩力学特性、作用机制及涌水突泥灾害风险进行分析。研究表明:1)王家寨隧道第三系半成岩遇水软化特性明显,随着含水率增加其黏聚力先增后减,内摩擦角不断减小,含水率为18%时黏聚力与内摩擦角分别为12.53 k Pa和7.35°,围岩逐渐失稳。2)软弱的第三系半成岩、高地下水量及隧道开挖扰动为王家寨隧道第三系半成岩富水段发生涌水突泥灾害的主要影响因素。3)王家寨隧道第三系半成岩段可按工程地质条件、水文地质条件划分为A、B、C、D 4段,各段涌水突泥灾害风险由大到小排序为B段=C段>A段>D段,其中评估的A段涌泥量与实际涌泥量较为吻合。