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超声波波速测试作为一种无损检测已经广泛应用到岩土工程行业,该测试方法也是获得岩土体物理力学参数的有效方法.目前鲜有关于冻土的声波测试的技术和方法的报导,已有的冻土声波测试都是在垂直方向上忽略换能器的质量并在常温下快速测试声波通过时间,难以满足测试精度.鉴此,在购置常温声波测试主机的基础上,充分考虑冻土对温度敏感的特性、换能器在水平方向的测试以及土样与换能器之间的耦合程度,设计了一种适用于多种类型的冻土超声波换能器支架和恒温箱的测试系统,恒温箱意在提供适合不同温度下土体的测试环境(-30℃~+30℃),换能器支架可供低温、提供多种尺寸冻土试样的横波和纵波的测试平台.为避免垂直测试中换能器和土样自身对测试的影响,除了支架提供水平测试平台外,在调节换能器与土样接触距离的螺杆顶端放置应变片测试冻土样与换能器之间的接触程度以提高冻土声波波速的测试精度.利用该测试系统对不同负温下冻土样品进行测试,数据结果证明了该测试系统的实用性和良好的测试精度.
As a kind of nondestructive testing, ultrasonic wave velocity testing has been widely applied to geotechnical engineering, and the testing method is also an effective method to get physical and mechanical parameters of rock and soil mass. There are few reports on the techniques and methods of acoustic testing of frozen soils Of the frozen soil acoustic testing are to ignore the transducer in the vertical direction of the quality and rapid testing at room temperature, the sound wave through time, it is difficult to meet the test accuracy. In view of this, in the purchase of the host room temperature sonic test, taking full account of the permafrost Temperature-sensitive characteristics of the transducer in the horizontal direction of the test and the degree of soil and the coupling between the transducer designed a suitable for a variety of types of frozen soil ultrasonic transducer bracket and incubator test system, The thermostat is intended to provide a test environment suitable for soil at different temperatures (-30 ° C to + 30 ° C) and a transducer support for cryogenic temperatures, providing a test platform for both S-wave and P- In the vertical test, the impact of the transducer and the soil itself on the test, in addition to the support provided horizontal test platform, placed in the top of the screw to adjust the distance between the transducer and the soil sample strain gauge test frozen The contact degree between soil sample and transducer is increased to improve the testing accuracy of the sound wave velocity of frozen soil.Using the test system to test frozen soil samples with different negative temperature, the data prove the practicability and good test of the test system Accuracy.