不同结构形式的后期热液充填裂隙花岗岩常温下物理力学性质研究  

Study on physical and mechanical properties of fracture granite filled with hydrothermal fluid with different types at room temperature

作　　者：石晓巅 武治盛 冯子军[1,2] 惠峥 赵阳升[1,2] SHI Xiaodian;WU Zhisheng;FENG Zijun;HUI Zheng;ZHAO Yangsheng(Key Laboratory of In-situ Modified Mining Ministry of Education,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China;Department of Mining Engineering,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,山西太原030024 [2]太原理工大学采矿工程系,山西太原030024

出　　处：《岩石力学与工程学报》2021年第1期147-157,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(U1810104,11772213)。

摘　　要：在干热岩开采的实际工程中,利用岩体结构面作为热交换通道将减小工程投入,并获得更好的工程效果。而在实际中花岗岩体中的结构面通常被热液充填,形成后期热液充填花岗岩体。研究后期热液填充裂隙花岗岩体的物理力学性质对实际地热开发中建设人工储留层具有重要指导意义。利用后期热液填充裂隙花岗岩体制备不同结构形式试样,在常温下对4种结构形式(上下结构、左右结构、母岩、充填体)的花岗岩试样进行纵波波速检测试验、抗压强度试验和对5种结构形式(边界充填体、母岩、充填体、左右结构、边界母岩)的花岗岩试样进行抗拉强度试验、渗透率测定试验。试验结果表明:(1)常温下4种结构形式的试样中,纵波传播速度vP大小关系为:上下结构、左右结构>母岩>充填体。在10 MPa围压下,4种花岗岩岩样峰值强度?c均值大小关系为:上下结构>左右结构>充填体>母岩,在相同围压下,5种花岗岩岩样渗透率k的大小关系为:充填体>母岩>边界充填体>左右结构花岗岩>边界母岩。在热液充填后,胶结面处花岗岩的孔隙度、渗透率减小,纵波波速、抗压强度增大;(2)在热液充填过程中,胶结面处母岩矿物颗粒发生熔蚀,且热液进入母岩孔隙裂隙,热液冷却结晶后对胶结面处的"黏合"和"愈合"作用是胶结面处花岗岩物理力学性质发生改变的原因。(3)常温下5种花岗岩岩样抗拉强度?t均值大小关系为:母岩>边界母岩>左右结构>边界充填体>充填体,后期热液充填裂隙花岗岩体中,充填体成为岩体的抗拉薄弱处,因此在"断层模式"的地热开发中,可对充填体处进行人工压裂建造人工储留层,大大节省其建造成本。In the practical engineering of dry hot rock mining,using rock discontinuities as heat exchange channels will reduce the project investment and obtain better engineering effect.In practice,rock discontinuous structural planes in granite mass are usually filled by hydrothermal fluid,forming fracture granite filled with hydrothermal fluid.Therefore,studies on the physical and mechanical properties of fracture granite filled with hydrothermal fluid are of great significance for the construction of artificial reservoir in the actual geothermal development.In this paper,the samples with different structural types are prepared from the later hydrothermal fluid filled fractured granite mass,and at room temperature,P-wave velocity and compressive strength tests on four structural types(up-down structure,left-right structure,parent rock and filling)of granite samples,and tensile strength and permeability tests on five structural types of granite samples(boundary filling,parent rock,filling,left-right structure and boundary parent rock),were performed.The results show that,at room temperature,P-wave velocity of up-down and left-right structures is the largest,followed by mother rock and filling body,that under 10 MPa confining pressure,the average value of the compressive peak strength?c from large to small is up-down structure,left-right structure,filling and parent rock,and that under the same confining pressure,the permeability k of five types of granite samples from maximum to minimum is filling,parent rock,boundary filling,left-right structural granite and boundary parent rock.After hydrothermal filling,the porosity and the permeability at the cementation surface decrease while the P-wave velocity and the compressive strength increase.The parent rock mineral particles at the cementation surface melt and the hydrothermal fluid enters into the fissures or pores of the parent rock in the process of hydrothermal filling,and after the hydrothermal cooling and crystallization,the"adhesion"and"healing"of the cementation surf

关 键 词：岩石力学 裂隙花岗岩 热液充填 纵波波速 渗透率 力学性质 干热岩 

分 类 号：TU45[建筑科学—岩土工程]