摘要
含水层内水压以能量的形式传递,其传递速率远大于水质点的迁移速率,水压传递速率对高压水体下工程安全施工及灾害预测预报具有重要意义。以无黏性土承压含水层为研究对象,通过理论分析、数值模拟、现场试验及室内物理模型试验等方法对水压传递速率变化规律进行探讨。结果表明:含水层中水压变化传递具有明显的滞后性,传递速率并不是无限大或接近声速,且存在随传递距离增加逐渐衰减的现象,水压径向传递的滞后时间t与水压传递距离r呈二次幂函数关系;稳定边界压力水头越大,在承压含水层中同等水压变量的传递速率越快,渗透系数越大水压传递速率越快;当渗透系数一定时,水压传递滞后时间与传播距离的拟合系数C随边界稳定压力水头的增加呈一阶指数函数减小;现场试验表明,边界稳定压力水头差异性不大时,在传输距离较远的条件下,其水压传递平均速率基本相当;室内试验表明,瞬态脉冲水压力随传递距离增加,波形发生明显变异,峰值压力逐渐减小、脉冲压力波波长变大、峰值压力传递速率减小,随传输距离的增加其传递速率呈指数函数衰减,说明瞬态脉冲水压力能量随传输距离增加快速衰减;瞬态脉冲压力值越大其初始阶段的传递速率越快,但随传输距离的增加其传递速率衰减幅度更大。研究成果对水压传递速率变化规律的影响机制及其应用于地下工程突水灾害预测及防治具有重要的理论及实践指导意义。
The water pressure in aquifers is transmitted as energy,with a transmission rate much higher than the migration rate of water particles.The water-pressure transmission rate holds great significance for the safe construction and disaster forecast and prediction of underground engineering under high-pressure water aquifers and bodies.Focusing on the confined aquifers bearing no cohesive soil,this study explored the law governing the changes in the water-pressure transmission rate through theoretical analysis,numerical simulations,field experiments,and laboratory physical model tests.Key findings are as follows:(1)The transmission of water-pressure changes in the aquifers exhibited noticeable hysteresis.The transmission rate was not infinitely high or close to the speed of sound,being subjected to gradual decay with increasing transmission distance.For the radial transmission of the water pressure,there was a quadratic function relationship between the lag time t and the distance r.(2)A higher stable-boundary hydraulic head corresponded to a higher transmission rate under the same water pressure in the confined aquifers,and a greater permeability coefficient was associated with a higher water-pressure transmission rate.(3)Under a certain permeability coefficient,the fitting coefficient C between the lag time and distance of the water-pressure transmission decreased exponentially with an increase in the stable-boundary hydraulic head.(4)Field tests show that when the stable-boundary hydraulic head differed slightly,the average water-pressure transmission rate roughly remained the same in the case of a long transmission distance.(5)As indicated by laboratory tests,with an increase in the transmission distance,the transient pulse water pressure exhibited significant variations in waveforms,a gradual decrease in the peak pressure,prolonged wavelength of pulse pressure waves,and a decrease in the transmission rate of the peak pressure.The transmission rate of the transient pulse water pressure decreased exponentially wit
作者
王文学
王柏森
高艳卫
吴冰
聂天宇
WANG Wenxue;WANG Bosen;GAO Yanwei;WU Bing;NIE Tianyu(Henan Province Key Laboratory of Rock and Soil Mechanics and Structural Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450045,China;Key Laboratory of Xinjiang Coal Bearing Resources Exploration and Exploitation,Urumqi 830023,China;Henan Provincial International Joint Laboratory for Landslide Flow Monitoring and Early Warning,North China University of Water Resources and Electric Power,Zhengzhou 450045,China;China Aerospace Planning and Design Group Co.,Ltd.,Beijing 102627,China)
出处
《煤田地质与勘探》
EI
CAS
CSCD
北大核心
2024年第3期79-88,共10页
Coal Geology & Exploration
基金
国家自然科学基金项目(41602298)
河南省高等学校重点科研项目(22A170013)
河南省本科高校青年骨干教师培养计划项目(2023GGJS67)。
关键词
无黏性土
承压含水层
水压力传递速率
滞后效应
压力传导系数
衰减规律
cohesionless soil
confined aquifer
water pressure transmission rate
hysteresis effect
coefficient of pressure conductivity
decay law
