摘要
【目的】四川盆地东南部灰岩陡高边坡十分发育,研究其地貌演化规律有助于推动防灾减灾学科的发展。【方法】以南川金佛山甄子岩为例,用地貌学方法分析了该地区地貌演化过程。【结果】甄子岩地貌具有阶梯状层状地貌特征,存在两级显著的夷平面,两级陡崖短期内局部后退,较长时间尺度表现为两级陡崖平行后退。由软、硬岩性组合的的两级陡崖上发育了大量的危岩,由于多因素影响,侧向卸荷、软、硬岩组合及外力地质作用使甄子岩陡崖上危岩体形成具有3种典型结构面,即水平状原生结构面、顶部坡肩卸荷拉裂面及底部软、硬岩界面的拉裂面,使危岩体具有类砌体结构面特征,其破坏具有塔状压裂座溃破坏、板状倾倒式破坏及塑流-拉裂破坏3种典型破坏模式。新构造运动、长江水系归并重组的过程中对川东南的地貌进行了明显的改造,在外力地质作用下加剧陡崖边坡的演化。【结论】研究成果为进一步研究灰岩陡崖演化的力学机制提供重要的科学依据。
[Purposes]The steep slopes of limestone in the southeastern part of the Sichuan Basin are well developed.Studying the laws of the evolution of the landforms will help promote the development of disaster prevention and reduction disciplines.[Methods]Taking the Zhenziyan Nanchuan as an example,the geomorphological method was used to analyze the evolution process of the geomorphology in this area.[Findings]The Zhenziyan landscape has the characteristics of stair-like layered geomorphology and two significant levels of planation surface.The two-step cliffs are partially retreated within a short period of time,and the long-time scales show that the two cliffs recede in parallel.The cliff that combination of soft and hard rock of the Zhenziyan is formed with a large number of perilous rocks.Due to the multi-factor influence,lateral unloading,combination of soft and hard rocks and external geological geology can make the perilous rock mass of the Zhenziyan steep cliff form three typical structural planes.The three typical structural planes,that is the level-like primary structural plane,the top slope shoulder unloading tensile fracture plane and the bottom soft and hard rock interface fracture surface.They make the perilous rock have the characteristics of masonry-like structural plane,fracturing pedestal collapse,plate pouring failure and plastic flow-fracture failure three typical failure modes.Neotectonic movement,the merger and reorganization of the Yangtze River water system in the process of transformation of the landscape of southeastern Sichuan has been significantly transformed.The evolution of cliff is being aggravated by exogenic geological process.[Conclusions]The research results provide important scientific basis for further study of the mechanical mechanism of the evolution of steep cliffs in limestone.
作者
唐红梅
张旭晨
王林峰
沈吉贵
TANG Hongmei;ZHANG Xuchen;WANG Linfeng;SHEN Jigui(Institute of Geotechnical Engineering,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《重庆师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2018年第5期54-62,共9页
Journal of Chongqing Normal University:Natural Science
基金
国家自然科学基金(No.51378521
No.51678097)
关键词
地貌演化
川东南灰岩地区
陡高边坡
危岩
landform evolution
limestone area in southeastern Sichuan
steep and high slope
perilous rock
