连通双岩溶洞穴系统强迫流示踪实验与洞穴体积计算方法

Forced Convection Tracing Experiment and Volume Calculation of Dual Karst Caves Connected

通过两个相互连通但体积不等、形状不同的洞穴按不同体积比和不同连通通道宽度的系列示踪实验,得到了连通双岩溶洞穴的强迫流示踪曲线模型,并提出了洞穴体积计算方法.分别在大、小洞穴中所获得的强迫流示踪曲线,其浓度达到稳定前的最后浓度变化段,前者长度短,坡度缓,后者长度长,坡度陡.当钻孔揭露与大洞穴连通的小洞穴时,可通过强迫流示踪曲线识别连通双岩溶洞穴与封闭孤立洞穴;连通双岩溶洞穴总体积计算的相对误差很小,说明所提出的总体积计算方法是可行的.但只有当钻孔揭露与大洞穴连通的小洞穴时,才可以通过示踪曲线单独计算各洞穴的体积.

The forced convection tracer curve model and the volume calculation method of connected dual Karst caves was obtained from those tracing experiments in two connected curves by changing the volume ratio of the two caves and the channel width. From the forced convection tracer curves gained in the big cave and the small one,the former has longer length and gentler slope and the latter has shorter one and steeper one before the tracer concentration becomes stable. When it is a small drilling-revealed subsurface cave connecting a big one,this method can identify the dual connected caves and isolated cave by the forced convection tracer curve;The relative error of the total volume of the two connected Karst caves is very small,which can indicate that the method of calculating the total volume is feasible. But only when the small drilling-revealed cave connected a big one,the method of calculating the volume of each cave through the tracer curve can be used.