【摘要】 基于现场开展土体液化问题研究势必成为今后土动力学中的一个重要发展方向。目前人工激振下的现场液化试验方法还不够成熟,尚需进一步探索和发展。本文从试验设备组成、场地地震动激励、试坑布置、饱和砂土模型制备、数据测量与采集等5个方面论述该方法中的主要技术问题。研究表明:动力加载系统激励产生的地震动在0~7m/s2;系统工作频率13~15Hz,饱和砂土模型与基础边缘的距离在0.5~2.5m范围内,更适合进行液化试验;应用水沉法现场制备饱和砂土模型,要重点注意试坑防水和尺寸定位的问题;数据测量与采集中要充分考虑对现场液化问题认识不够这一因素的影响,需对数据测量与采集提出附加要求;试验实例初步表明,该方法可行,适合开展液化问题研究。更多还原

【Abstract】 Research on soil liquefaction under in-situ conditions will be an important branch in soil dynamics.At present,in-situ liquefaction test under artificial dynamic loading remains at the research stage;there have been only a few studies.This paper presents a method for in-situ liquefaction test based on a remolded saturated sand model.Many technological problems related to this method are discussed,which include five parts:(1)test apparatus,(2)ground motion stimulation,(3)test pit arrangement,(4)saturated soil model preparation,and(5)data measurement and acquisition.An in-situ liquefaction test using this method was performed in this study.The surface soil acceleration and pore water pressure data indicate that soil liquefaction occurs under artificial dynamic loading.The main points are:(1)A dynamic loading system can simulate strong ground motion with an acceleration from 0to 7m/s2.(2)Under a loading frequency of 13 Hz to 15 Hz,the soil liquefaction test can be performed relatively easily when the distance between the soil model and loading base is 0.5 mto 2.5 m.(3)Measurement positioning and water-proofing are key factors during the preparation of the saturated soil model.(4)More request in data measurement and acquisition should be raised because of little acknowledges for soil liquefaction at site.(5)Experimental results indicate that this technology is practically feasible.Studies on special liquefaction problems can be performed using this method.It also paves the path for further studies on geotechnical in-situ testing techniques under artificial dynamic loading.更多还原