深圳罗湖断裂带构造活动性研究及对工程的影响

发布时间：2018-06-12 22:51

本文选题：罗湖断裂带 + 构造活动性　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：罗湖断裂带位于深圳断裂带的西南段,主要由一系列北东向断层和少量北西向断层组成。分析前人研究成果发现,对深圳断裂带的构造活动主要存在两点争议:一是断裂带内的构造变形机制划分太笼统,没有具体细分;二是断裂带构造活动的时限存在分歧,特别是脆性变形活动的时限。通过对春风隧道复杂断裂带构造特征的研究和分析,运用3Dmine软件建立春风隧道复杂断裂带的三维展布图,在结合K-Ar法、ESR法和14C法等测年的基础上,探讨了罗湖断裂带的构造活动性,进而分析了断裂构造对春风隧道工程的影响。主要的结论有以下几点:(1)通过对钻孔的构造解析,综合分析断裂的运动学要素及伴生构造特征,认为罗湖断裂带在早期韧性变形的基础上,至少叠加了两期脆性变形。K-Ar法伊利石断层泥测年确定了后两期脆性变形活动的时代分别为晚白垩世末期-早古新世初期,始新世中期;ESR法测年结果限定了罗湖断裂带的最后一次明显构造活动的上限,为发生在中更新世中期。(2)砾石层上部或者含砾砂层上部有机质14C测年为晚更新世中期,砾石层顶底界面在不同地段深度虽有差异,但是总体都呈连续缓波状变化趋势,没有发生明显的突变,表明自砾石层沉积之后,构造活动很微弱,地壳稳定性较好,断层没有明显的活动痕迹。(3)依据断裂构造活动性研究,证明罗湖断裂带没有明显的应力、能量集中现象,自中更新世中期以来其活动明显减弱,不存在断层突发性活动的可能,区域稳定较好,断裂带本身活动性对春风隧道工程没有影响。(4)断层破碎带分析表明,春风隧道开挖至断层破碎带时,由于破碎带本身稳定性较差,突然的应力释放使围岩结构更加松散,稳定性加速降低,隧道可能发生隧道突水和垮塌工程事故,在某些地段还可能引发地表沉降。
[Abstract]:The Luohu fault zone is located in the southwest section of the Shenzhen fault zone, mainly composed of a series of north-east faults and a small number of North West faults. The results of previous studies have found that there are two main controversies in the tectonic activity of the Shenzhen fault zone: first, the structural deformation mechanism in the fault zone is divided into too general and no specific subdivision, and two is the fault zone structure. The time limit of the activity is different, especially the time limit of the brittle deformation activity. Through the study and analysis of the structural characteristics of the complex fault zone in the spring wind tunnel, the three-dimensional distribution map of the complex fault zone of the spring wind tunnel is established by 3Dmine software. On the basis of the K-Ar, ESR and 14C methods, the structural activity of the fault zone is discussed. The main conclusions are as follows: (1) by analyzing the structure of the borehole, analyzing the kinematic elements of the fracture and the characteristics of the associated structure, it is considered that the Luohu fault zone, on the basis of early ductile deformation, at least superimposed the two phase brittle deformation.K-Ar method of illite fault mud measurement. The period of the latter two periods of brittle deformation was determined in the late Late Cretaceous early Palaeocene epoch and the middle Eocene, and the results of ESR dating limited the upper limit of the last obvious tectonic activity in the Luohu fault zone, which occurred at the middle of the Middle Pleistocene. (2) the 14C dating of the upper or the upper gravel layer of the gravel layer was late renewal. In the middle of the world, the top and bottom interface of the gravel layer is different in different depth, but the trend of continuous slow wave changes in the whole, and there is no obvious mutation. It shows that the tectonic activity is very weak after the gravel layer deposition, the stability of the crust is good, and the fault has no obvious trace of activity. (3) according to the activity of fracture structure, it is proved that Luohu There is no obvious stress and energy concentration in the fault zone. Since mid Pleistocene, its activity has been weakened obviously, there is no possibility of fault sudden activity, the regional stability is better, the activity of the fault zone has no effect on the spring wind tunnel project. (4) fault fracture zone analysis shows that when the spring wind tunnel is excavated to the fault zone, it is broken. The stability of the belt itself is poor, the sudden stress release makes the surrounding rock structure more loose, the stability acceleration decreases, tunnel water inrush and collapse may occur in tunnel, and the surface settlement may also be triggered in some sections.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P542.3;P642

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