岩土离心模型试验软接触式微型土压计研制及性能评价  

Development and performance evaluation of a soft-contact earth pressure transducer for geotechnical centrifuge modeling

作　　者：王永志[1,2] 杨阳 徐光明[3] 汤兆光 张雪东[4] 孙锐 周燕国[5] WANG Yongzhi;YANG Yang;XU Guangming;TANG Zhaoguang;ZHANG Xuedong;SUN Rui;ZHOU Yanguo(Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Disaster Mitigation,Ministry of Emergency Management,Harbin150080,China;Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210024,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Institute of Geotechnical Engineering,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]中国地震局工程力学研究所地震工程与工程振动重点实验室,黑龙江哈尔滨150080 [2]地震灾害防治应急管理部重点实验室,黑龙江哈尔滨150080 [3]南京水利科学研究院岩土工程研究所,江苏南京210024 [4]中国水利水电科学研究院,北京100038 [5]浙江大学岩土工程研究所,浙江杭州310058

出　　处：《岩土工程学报》2024年第8期1655-1664,共10页Chinese Journal of Geotechnical Engineering

基　　金：中国地震局工程力学研究所基本科研业务费专项项目(2023B08);国家自然科学基金项目(52278374,519786131);黑龙江省自然科学基金项目(LH2023E019)。

摘　　要：微型土压计是岩土离心模型试验的重要测量技术之一。为解决刚性土压计测量中拱效应、尺寸效应、厚径比等经典误差问题及提升频响速率和精度,尝试开发了一种全新软接触式微型土压计ESP-II,介绍了其技术创新和设计方法。以两种国际代表性土压计为参考,设计开展一系列离心模型试验,对其感应精度、速率和适用性进行评价。主要结论:①逐级加载离心加速度5g~50g试验下,各深度ESP-II和两种参考传感器测试结果与理论值的平均误差分别为5.16%,6.70%,4.85%,三者沿深度拟合K_(0)优度系数R^(2)均≥0.9893。②脉冲荷载试验中ESP-II最大响应时间约7.8 ms,略优于两种参考传感器,具有良好的频响速率。③不同幅值正弦、地震等动荷载试验下,3种传感器测得土压力均呈一致增量趋势,K_(0)约由0.43~0.45增至0.51~0.56,与既有规律认识吻合。④离心机下降卸荷过程中,ESP-II测得时程表现良好连续性和光滑性,反映软接触式设计有利于保障土体与传感器良好接触和稳定响应。研究成果,初步证明了软接触式土压计适应于静、动力离心试验需求,具有重要价值与应用前景。The miniature earth pressure transducer is one of the key testing tools in geotechnical centrifuge modeling.Aiming at solving the classical problems such as arching effects,size effects and thickness-diameter ratio in the measurement of rigid transducers,and improving the frequency response rate and induction accuracy,a soft-contact pressure transducer ESP-II is developed,and its innovations and design methods are introduced.Taking two internationally representative earth pressure transducers as reference,a series of centrifugal model tests are designed and carried out to evaluate its accuracy,frequency response and applicability.The main conclusions are as follows:(1)In the static centrifugal acceleration tests spinning up from 5g to 50g,the difference between the theoretical values and the test results of ESP-II and the two reference transducers at each depth is small,and the average deviations are 5.16%,6.70%and 4.85%,respectively.The coefficient R^(2) of the three curves K_(0) fitted along the depth is≥0.9893.(2)In the pulse load tests,the maximum response time of ESP-II is about 7.8 ms,which is slightly better than that of the two reference transducers and has a satisfactory frequency response.(3)In the dynamic load tests of sine and seismic with different amplitudes,the incremental trend of earth pressure measured by the three transducers is basically consistent.The variation range of K_(0) increases from 0.43~0.45 before the seismic to 0.51~0.56 after the seismic, which is consistent with the existing theory. (4) Atthe decelerating stage of the centrifuge, the good continuity and smoothness of the time history measured by the ESP-II, whichreflects the soft-contact design, is conducive to ensuring good contact and stable response between the soil and the transducer.The research results have preliminarily proved that the developed soft-contact transducer ESP-II satisfies the requirements ofstatic and dynamic centrifugal tests, with significant application value and immense potential.

关 键 词：岩土离心模型试验 微型土压计 设计方法 软接触式 性能评价 

分 类 号：TU432[建筑科学—岩土工程]