缓倾岩层洞穴系统发育模式的模拟试验

SIMULATION TEST OF MODEL FOR DEVELOPMENT OF CAVE SYSTEM IN GENTLY DIPPING-ROCKS

为模拟洞穴系统的发生、演化及分布规律。对缓倾岩层(倾角<15°)裂隙疏散或密集及多层或单层含水层结构的模型所做的溶蚀试验表明:均匀介质含水层在平面上洞穴发育呈不均匀状况,剖面上以浅饱水带及承压含水层顶板附近洞穴较发育;在裂隙不发育或不贯通时洞穴发育受层面裂隙控制;在缓倾岩层中,洞穴发育循反倾向的方向逐渐减弱。

A model made of homogeneously mixed gypsum,salt and water as a medium similar to that of various geological and hydrogeological structures set in a special test tank which is desi- gned to be a system for water supply runoff and drain was simulated to reveal the formation, evalution and the regularities of distribution cave system and to observe karstification in a water-saturated zone. A preliminary result of the model of gentl dipping strata(dip angle<15°)with dense and sparse cracks and multilayer aquifers or singlelayer aquifer structure shows that the homo- genic aquifer on plane provides a nonuniform condition for developing caves,which are more developed near the top of confined aquifer and in shallow water-satarated zone on the profile. Cave development is controlled by cracks on bedding plane when the cracks did not be deve- loped or connected in the rock formation.The karstification decreases gradually in an antidip deriction when a rock formation lies at a gentle dip angle.