单位文秘网 2021-07-26 08:13:15 点击: 次
收稿日期:20130908
基金项目:国家自然科学基金项目(50978016)
作者简介:黄明利(1969),男,黑龙江双城人,教授,博士研究生导师,工学博士,博士后,Email:huang_mingli@126.com。
摘要:为了能在隧道掌子面或基坑侧壁上直接进行岩土体力学参数的测量,提出了一种在岩土体内沿水平方向钻孔测量其力学参数的原位测试方法,研制了其配套装置,从而避免从地面打孔进行土体力学参数测量的繁琐工序,并对该装置的设计思想和使用方法做了明确具体的介绍。针对该装置的不等压扩孔问题,采用弹性力学的方法给出了该装置测量岩土体力学参数的解析理论依据,并利用数值方法对解析理论做了验证。采用数值模拟方法研究了弹性模型、摩尔库仑模型下多组参数的检测结果。结果表明:该装置的弹性解析理论在较大粘聚力、内摩擦角的岩土体中的检测结果是准确的。该装置可以随理论研究的不断加深而得到广泛的应用。
关键词:岩土体;水平孔;原位测试;力学参数;不等压扩孔;解析理论
中图分类号:TU413文献标志码:A
Measured Device and Theory of Mechanical Parameters in
Horizontal Cavity of Rock and SoilHUANG Mingli, LI Ning
(Tunnel and Underground Engineering Research Center of Ministry of Education,
Beijing Jiaotong University, Beijing 100044, China)Abstract: In order to get the mechanical parameters of rock and soil just only on the surface of tunnels and foundation pits, a new in situ test method for measuring its mechanical parameters along horizontal cavity direction which was used in rock and soil was put forward, and a device supported this method was also researched and designed. So this would avoid the inconvenient working procedure of punching from ground surface to tunnels face. The design cogitation and the manipulation method of the device were also definitely and concretely introduced. The essence of this method was inisotonic cavity expansion problem. For this problem, using the method of elasticity, analytic theory of testing the elastic parameters of rock and soil by this device was given, and there was also a numerical testify for this analytic theory. Finally, this test method was simulated by numerical method which involved several groups of parameters of elastic model and MohrCoulomb model. The results show that it can be concluded that the elastic analytic theory can be used in the rock and soil with high values of cohesive force and internal friction angle. This device can be used in a wider place along with the development of theoretical research.
Key words: rock and soil; horizontal cavity; in situ test; mechanical parameter; inisotonic cavity expansion; analytic theory
0引言
在岩土工程中,岩土体的力学参数对工程结构的变形起主要的影响,目前,获取岩土体力学参数的方法分为室内试验、原位测试2大类。由于室内试验不可避免地对土样产生扰动,并且试样缺乏代表性[1],因此,室内试验得到的参数难以准确反映实际工程中岩土体的性质[2]。沈珠江认为可靠的土质参数只能通过原位测试取得[34]。原位测试又称现场试验,是岩土体保持或基本保持其所处位置与天然结构、湿度和应力状态情况下进行的各种测试[5]。现在常用的原位测试方法主要包括荷载试验、触探试验、剪切试验、侧胀试验、岩体原位应力测试、动力参数测试[6],其中前3种更为常见。
上述常用的原位测试方法的主要缺点就是测试机理不明确,取得参数的方法往往建立在经验和半经验公式基础上[78],另外,测试工序繁琐,机器庞大,费用昂贵。在基坑工程、城市地铁、山岭隧道等岩土工程中,若工程开挖后出现了未知的新土层,则需要测得新土层的原位力学参数,或对注浆后的土体进行效果检验,此时,若使用上述的原位测试方法,则需要从地面打孔至待测土体的位置进行测量,费时,费力,破坏环境。若能直接利用隧道掌子面或基坑侧壁,就可避免从地面打孔的繁琐工序,因此,本文中笔者提出了一种在岩土体内沿水平方向钻孔测量其力学参数的方法,并且研制了其配套装置。
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