公路隧道围岩的区间数组合分类法

公路隧道围岩的分类方法较多,每一种分类方法的结果都是对真实围岩状况的一种估计,通过一定的算法将这些分类结果进行合成,可以使各分类法取长补短,围岩信息得到充分利用。基于上述思路,并考虑到分类标准和被分类隧道围岩物理力学指标均为区间数的实际情况,提出了一种基于区间数的公路隧道围岩组合分类法。为充分利用区间数携带的信息,定义了一种新的区间数距离计算方法,选择能够兼顾各单一分类法之间功能性和协调性要求的加乘混合函数作为围岩分类函数,计算被分类围岩与分类标准各级别之间的分类函数值,最小值对应的类别即为被分类围岩的类别。针对某工程隧道2个典型段围岩的分类问题,在隧道围岩常用的岩芯质量指标ROD法、《公路隧道设计规范》(JTGD70-2004)BQ值法和弹性波速vp法进行分类的基础上,采用本文方法进行组合分类,结果表明:本文方法物理意义明确,计算过程简捷,分类指标稳定,分类结果与单一分类法相比能够更好地反映实际围岩状况,可供公路隧道勘察、设计、施工时参考。

Interval numbers-based integrated classification method for surrounding rock of highway tunnel

There were many methods of classification for surrounding rock of highway tunnel nowadays.The results from any individual method could be assumed as an estimation of the practical situation.Combining these methods by a definite algorithm could enhance the advantages and overcome the disadvantages inherited in them,and the information of the surrounding rock could be used sufficiently in classification as well.Based on the above thought,and considering the situation that the parameters of surrounding rock and the classification standard were stated in the form of interval numbers,a new interval numbers-based integrated classification method for surrounding rock of highway tunnel was proposed.In order to reduce the information loss in calculation process,a new definition of distance between the two interval numbers was given.And a combined algorithm with addition and multiplication was selected as the classification function which could take functionality and coordination of the employed methods into account.By using the function,the value of classification index was calculated.The subject was classified corresponding to the minimum value of classification index.A practical highway tunnel with two typical sections was taken as an example.Firstly,three classification methods,i.e.,rock quality designation system ROD,rock basic quality system BQ and wave velocity vp of the rock were employed to classify the surrounding rock individually.Then the proposed method was used to get the final value classification index.The method was recommended for its clear modeling,tangible physical significance and simple calculations.It was shown that the proposed method was concise,stable and practical.