连拱隧道模型试验中的量测方法应用研究

为准确采集地质力学模型试验中的试验数据,以连拱隧道的模型试验为例,研究采用压力盒、数码图像分析系统、自制沉降板等仪器以及基于图像相关分析的模型试验变形场量测方法,进行应力、应变及变形场的量测。通过对量测结果的分析对比表明,数码图像分析量测技术应用于岩土工程的模型试验,所测变形场规律性好,与试验过程中各种现象拟合好,与对应点沉降板的测量结果很接近,并且与传统方法相比,量测变形场范围广,对模型试验本身基本无扰动和影响;在一定变形范围内,模型试验无需布设任何实际量测标点或描画网格,直接利用数码图像分析方法,是一种简便有效且经济实用的变形场非接触量测方法。多种量测方法的应用实现了真正意义上的连拱隧道三维地质力学模型试验应力及变形场的量测,取得了令人满意的效果。

Study on the Measurement Methods for Model Test of Double-Arch Tunnel

For accurately obtaining the test data of the geo-mechanical model test,as an example in the double-arch tunnel model tests,the technique of measurement is studied in present paper.Applied with earth-pressure cell,digital camera,settlement plate and the method of digital image analysis,the distribution of stress and deformation in the wall rock mass were measured during the tunnel excavation.By analyzing and comparing the test data,the reasonable regularity of the deformation field which is measured by digital image analysis are obtained in the geotechnical engineering model test.The results of measurement agree well with the settlement plate results and the range of the measurement scope is larger.Without any real measurement marker and grid,to a certainty range,the digital image analysis method can measure the deformation field only with the digital camera.The digital image analysis method which has no disturbance and influence to the model test itself is a convenient,effective and economic non-contact measurement method.The deformation field of model test is measured really by using multi-measurement methods and the effect is satisfying.