The complicated rock structures and the stability of surrounding rocks of the underground powerhouse were the key rock mechanical problems in Shuibuya hydropower station.In order to overcome the related rock mechanica...The complicated rock structures and the stability of surrounding rocks of the underground powerhouse were the key rock mechanical problems in Shuibuya hydropower station.In order to overcome the related rock mechanical problems encountered during its construction,a comprehensive research was carried out for the underground powerhouse in Shuibuya hydropower station based on a detailed geological survey.It covers the investigations on the initial in-situ stress distribution features,rock mechanical properties,engineering rock mass classifications by different methods,numerical modeling for stability and support analysis,proper measures for rock excavation and support.The results show that the rock excavations of the underground powerhouse under the given geological conditions can be controlled effectively.Some measures,suggested by the designers,are proved to be rational and effective.These measures mainly consist of:(1) the soft rock replacements by concrete in local area below the crane beam,(2) the shotcrete and reinforcement by rock bolts and anchor cables in surrounding rocks,and (3) 2 m concrete placement on the rock bench between adjacent tailrace tubes.The engineering practice shows that the treated surrounding rocks have a good overall stability.The deformation behaviors observed by safety equipments are within the designing limits.The research conclusions on the related rock mechanical problems,prior to the underground powerhouse excavations,are reliable.展开更多
There are fundamentally two different communication media in wireless underground sensor networks. The first of these is a solid medium where the sensor nodes are buried underground and wirelessly transmit data from u...There are fundamentally two different communication media in wireless underground sensor networks. The first of these is a solid medium where the sensor nodes are buried underground and wirelessly transmit data from underground to aboveground. The second is an underground medium such as tunnel, cave etc. and the data is transmitted from underground to the aboveground through partially solid medium. The quality of communication is greatly influenced by the humidity of the soil in both environments. The placement of wireless underground sensor nodes at hard-to-reach locations makes energy efficient work compulsory. In this paper, rule based collector station selection scheme is proposed for lossless data transmission in underground sensor networks. In order for sensor nodes to transmit energy-efficient lossless data, rulebased selection operations are carried out with the help of fuzzy logic. The proposed wireless underground sensor network is simulated using Riverbed software, and fuzzy logic-based selection scheme is implemented utilizing Matlab software. In order to evaluate the performance of the sensor network;the parameters of delay, throughput and energy consumption are investigated. Examining performance evaluation results, it is seen that average delay and maximum throughput are accomplished in the proposed underground sensor network. Under these conditions, it has been shown that the most appropriate collector station selection decision is made with the aim of minimizing energy consumption.展开更多
Compared with the space on the ground,if there is a fire in the urban complex underground space,the loss will be greatly harmful.In addition,the complex underground space is usually connected with other large space ar...Compared with the space on the ground,if there is a fire in the urban complex underground space,the loss will be greatly harmful.In addition,the complex underground space is usually connected with other large space areas and densely populated.Once a fire occurs in the complex underground space,it will cause huge property losses and casualties.In order to reduce the risk of fire,it is necessary to deeply understand the development rules and characteristics of fire in the complex underground space of the city.This article has mainly carried on the following work:(I)A particularly complex model of the multi‐storey subway station was built.On this basis,three groups of comparative experiments were conducted to study the effects of fire power,fire location and smoke control system on fire development,and the conclusion that fire location is the most important factor for fire development was obtained;(II)In order to explore the entire space fire and the local space fire,CFD(Computational Fluid Dynamics)is used to build a large‐size fire model and a small‐size fire model respectively;(III)Multiple detector data as temperature slices were built,and it is expected to make full use of the simulation data to deduce the important index of fire location in the early stage of fire.All of the works in this paper will provide reference experimental data for the prevention and firefighting of a sudden fire in the complex underground space.展开更多
POI是“Point of Interest”的缩写。每个POI包含四方面信息,名称、类别、坐标、分类,文章拟通过对地面空间和地下空间两个维度的用地构成、建筑类型与使用功能的研究分析,尝试探索基于POI的旧城核心区地铁站出入口设置的量化设计方法...POI是“Point of Interest”的缩写。每个POI包含四方面信息,名称、类别、坐标、分类,文章拟通过对地面空间和地下空间两个维度的用地构成、建筑类型与使用功能的研究分析,尝试探索基于POI的旧城核心区地铁站出入口设置的量化设计方法。文章通过文献研读、类比分析等研究手段,对国内外地铁站出入口设置进行了梳理与分析,弥补了旧城核心区地铁站出入口量化设置研究的理论空白,为国内类似项目提供了一定的设计研究素材。展开更多
基金Supported by the National Key Technology R&D Program of China (2008BAB29B01)
文摘The complicated rock structures and the stability of surrounding rocks of the underground powerhouse were the key rock mechanical problems in Shuibuya hydropower station.In order to overcome the related rock mechanical problems encountered during its construction,a comprehensive research was carried out for the underground powerhouse in Shuibuya hydropower station based on a detailed geological survey.It covers the investigations on the initial in-situ stress distribution features,rock mechanical properties,engineering rock mass classifications by different methods,numerical modeling for stability and support analysis,proper measures for rock excavation and support.The results show that the rock excavations of the underground powerhouse under the given geological conditions can be controlled effectively.Some measures,suggested by the designers,are proved to be rational and effective.These measures mainly consist of:(1) the soft rock replacements by concrete in local area below the crane beam,(2) the shotcrete and reinforcement by rock bolts and anchor cables in surrounding rocks,and (3) 2 m concrete placement on the rock bench between adjacent tailrace tubes.The engineering practice shows that the treated surrounding rocks have a good overall stability.The deformation behaviors observed by safety equipments are within the designing limits.The research conclusions on the related rock mechanical problems,prior to the underground powerhouse excavations,are reliable.
文摘There are fundamentally two different communication media in wireless underground sensor networks. The first of these is a solid medium where the sensor nodes are buried underground and wirelessly transmit data from underground to aboveground. The second is an underground medium such as tunnel, cave etc. and the data is transmitted from underground to the aboveground through partially solid medium. The quality of communication is greatly influenced by the humidity of the soil in both environments. The placement of wireless underground sensor nodes at hard-to-reach locations makes energy efficient work compulsory. In this paper, rule based collector station selection scheme is proposed for lossless data transmission in underground sensor networks. In order for sensor nodes to transmit energy-efficient lossless data, rulebased selection operations are carried out with the help of fuzzy logic. The proposed wireless underground sensor network is simulated using Riverbed software, and fuzzy logic-based selection scheme is implemented utilizing Matlab software. In order to evaluate the performance of the sensor network;the parameters of delay, throughput and energy consumption are investigated. Examining performance evaluation results, it is seen that average delay and maximum throughput are accomplished in the proposed underground sensor network. Under these conditions, it has been shown that the most appropriate collector station selection decision is made with the aim of minimizing energy consumption.
基金supported by Shenzhen Science and Technology Innovation Commission(NO.KCXFZ20211020163402004).
文摘Compared with the space on the ground,if there is a fire in the urban complex underground space,the loss will be greatly harmful.In addition,the complex underground space is usually connected with other large space areas and densely populated.Once a fire occurs in the complex underground space,it will cause huge property losses and casualties.In order to reduce the risk of fire,it is necessary to deeply understand the development rules and characteristics of fire in the complex underground space of the city.This article has mainly carried on the following work:(I)A particularly complex model of the multi‐storey subway station was built.On this basis,three groups of comparative experiments were conducted to study the effects of fire power,fire location and smoke control system on fire development,and the conclusion that fire location is the most important factor for fire development was obtained;(II)In order to explore the entire space fire and the local space fire,CFD(Computational Fluid Dynamics)is used to build a large‐size fire model and a small‐size fire model respectively;(III)Multiple detector data as temperature slices were built,and it is expected to make full use of the simulation data to deduce the important index of fire location in the early stage of fire.All of the works in this paper will provide reference experimental data for the prevention and firefighting of a sudden fire in the complex underground space.
文摘POI是“Point of Interest”的缩写。每个POI包含四方面信息,名称、类别、坐标、分类,文章拟通过对地面空间和地下空间两个维度的用地构成、建筑类型与使用功能的研究分析,尝试探索基于POI的旧城核心区地铁站出入口设置的量化设计方法。文章通过文献研读、类比分析等研究手段,对国内外地铁站出入口设置进行了梳理与分析,弥补了旧城核心区地铁站出入口量化设置研究的理论空白,为国内类似项目提供了一定的设计研究素材。
