大型数控拉拔试验系统的研制及应用

Development and application of large scale numerical control pullout test system

跟踪国内外研发现状,结合交通部西部膨胀土项目的开展,研制了CS-LB01大型数控土工合成材料拉拔试验系统。该系统具有试件尺寸大、可采用恒力或恒速两种控制方式实现土工合成材料在不同填料中的拉拔试验、较真实模拟实际工况的特点。加载方式也因上下箱体顶(底)面设置气囊并辅以稳压伺服控制系统、设法消除填土受上下盒侧壁的摩阻影响而更加科学合理。此外,采用高精度拉力和位移传感器、自行开发数据采集分析系统并配套填料压实和起吊辅助设备,使整个系统的人工智能化水平大大提高。试验表明,该系统能较好模拟土工格栅在膨胀土中的工作状态,准确提供筋土界面间的受力、变形及变化规律,从而方便试验参数的采集及对土中加筋作用机理的研究。

Aiming at the present situation of research and development of pullout test apparatus used to study the interaction between geosynethetic and soil at home and abroad, a large-scale pullout test system called CS-LB01 had been developed by Changsha University of Science and Technology combined with the expansive soil research project sponsored by the West Project Construction Office of Ministry of Communications of China. The characteristics of the test system were as follows： large scale sample can be tested; two test control methods including constant force control and speed control were alternated in the pullout tests on different soil samples and geosynethetic; the field condition were simulated. In addition, the loading method became more reasonable because air bags were set up on the surfaces and bottom of the box combining with the servo control loading system, and the influence of friction between test sample and both sides of box was eliminated. Furthermore, the test system was greatly improved by adopting high-precision force and displacement transducers and self-developed data acquisition system as compact and portable equipments. It was shown that the test system could be well used to simulate the realistic condition of reinforced expansive soil with geogrid, and to monitor the stress, deformation and the interaction between the soil and geogrid, then the acquisition of test parameters and the study on the reinforcing mechanism became more convenient.