岩溶地面塌陷三机理理论及其应用

Three-Mechanism Theory(TMT)of karst ground collapse and its application

为了给岩溶地面塌陷预测、监测、防治和应急措施提供理论依据,全面总结了岩溶地面塌陷的发育规律,认为岩溶、土体和诱发因素是岩溶地面塌陷的三要素。岩溶为土体丧失提供通道和储藏空间。土的工程地质性质决定了土体塌陷方式:"黏土块"坍塌、砂颗粒漏失、软弱土流失;土体塌陷方式决定了土体塌陷机理;据土体塌陷方式提出了由"土洞型塌陷""沙漏型塌陷"和"泥流型塌陷"构成的岩溶地面塌陷三机理理论:黏性土和密实砂性土层中,在外力作用下,土洞顶板拱效应失效而产生的地面塌陷现象称为土洞型塌陷;由于诱发因素的触发导致可溶岩上方松散砂层中砂颗粒漏失而产生的地面塌陷现象称为沙漏型塌陷;可溶岩上方软弱土体在外力作用下向可溶岩中流失而产生的地面塌陷现象称为泥流型塌陷。三机理理论关注土体塌陷方式,既解释了岩溶地面塌陷现象,更回答了土体"如何塌"的问题。诱发因素是塌陷的外部影响因素,不是塌陷机理的构成要素;诱发因素产生作用力;作用力改变土颗粒运动状态,使土颗粒由"静止→运动",土体由"稳定→塌陷"。依据三机理理论,提出了岩溶地面塌陷综合地质预测方法,建立了基于三个塌陷机理的土体塌陷确定性预测模型,系统总结了岩溶地面塌陷监测、防治和应急措施方法,形成了从理论到实践的、完整的岩溶地面塌陷思想体系。

In order to provide theoretical basis for the prediction,monitoring,prevention and emergency response of karst ground collapse,the development law of karst ground collapse is summarized.It is considered that the soil body,karst and inducing factors are the three elements leading to karst ground collapse.Karst provides passage and storage space for the failed soil body.The geotechnical properties of soil determine the ways of soil collapse:"clay block"collapse,sand particle leakage and soft soil loss.According to the mode of soil collapse,the Three-Mecha‐nism Theory of(TMT)of karst ground collapse,which is composed of"soil cave type collapse","hourglass type col‐lapse"and"mud flow type collapse",is put forward here.In cohesive soil and dense sandy soil layers,under the ac‐tion of the external force,the ground collapse caused by the failure of soil cave roof is called soil cave collapse.The ground collapse caused by the leakage of sand particles in the loose sand layer above the soluble rock is called hour‐glass collapse.The surface collapse caused by the loss of soft soil above the soluble rock to the soluble rock under the action of external force is called mudflow collapse.The TMT focuses on the way of soil collapse,which not on‐ly explains the phenomenon of karst ground collapse,but also answers the question of"how to collapse".The induc‐ing factors are the external influencing factors of ground subsidence,not the constituent elements of collapse mecha‐nism.Inducing factors produce acting force,which changes the movement state of soil particles,making the soil par‐ticles from“static”to“moving”,and the soil mass from“stability”to“collapse”.According to the TMT,a com‐prehensive geological prediction method of karst ground collapse is proposed,and a deterministic prediction model of soil collapse based on three collapse mechanisms is established.The monitoring,prevention and emergency mea‐sures of karst ground collapse are systematically summarized,and a complete karst ground collapse ideological sys‐tem from theory to practice is formed.