岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2014年
2期
390-395
,共6页
土力学%土工离心机%地裂缝扩展%隐伏断层%胶结黏土
土力學%土工離心機%地裂縫擴展%隱伏斷層%膠結黏土
토역학%토공리심궤%지렬봉확전%은복단층%효결점토
soil mechanics%geotechnical centrifuge%fault rupture propagation%pre-existing fracture%cemented clay
基岩断层错动而引起的上覆土体变形会对地表以及地下结构物造成破坏。上覆土体的胶结特性和隐伏断层的存在,使得断层错动的变形机制更为复杂。采用滤纸技术模拟隐伏断层,通过2组离心机试验研究胶结土体中正断层裂缝的扩展机制及伴随的孔压变化规律。对土体的变形分析和孔隙水压力的监测加深了对地裂缝的认识。研究发现,正断层错动引起胶结黏土的变形机制为受弯变形。隐伏断层使得土体受弯区变小、土体破坏程度加剧。胶结黏土受弯形成的地裂缝分为张拉裂缝和剪切裂缝,这些地裂缝的发展为超孔压的消散提供了优势路径。
基巖斷層錯動而引起的上覆土體變形會對地錶以及地下結構物造成破壞。上覆土體的膠結特性和隱伏斷層的存在,使得斷層錯動的變形機製更為複雜。採用濾紙技術模擬隱伏斷層,通過2組離心機試驗研究膠結土體中正斷層裂縫的擴展機製及伴隨的孔壓變化規律。對土體的變形分析和孔隙水壓力的鑑測加深瞭對地裂縫的認識。研究髮現,正斷層錯動引起膠結黏土的變形機製為受彎變形。隱伏斷層使得土體受彎區變小、土體破壞程度加劇。膠結黏土受彎形成的地裂縫分為張拉裂縫和剪切裂縫,這些地裂縫的髮展為超孔壓的消散提供瞭優勢路徑。
기암단층착동이인기적상복토체변형회대지표이급지하결구물조성파배。상복토체적효결특성화은복단층적존재,사득단층착동적변형궤제경위복잡。채용려지기술모의은복단층,통과2조리심궤시험연구효결토체중정단층렬봉적확전궤제급반수적공압변화규률。대토체적변형분석화공극수압력적감측가심료대지렬봉적인식。연구발현,정단층착동인기효결점토적변형궤제위수만변형。은복단층사득토체수만구변소、토체파배정도가극。효결점토수만형성적지렬봉분위장랍렬봉화전절렬봉,저사지렬봉적발전위초공압적소산제공료우세로경。
It is well-recognized that normal fault dislocation may cause severe damages to buildings and underground structures during earthquake. Understanding of deformation mechanisms of overlying soil becomes even more challenging in cemented soils with pre-existing fracture. Two groups of centrifuge tests were conducted to investigate deformation mechanism and variation of pore pressure during normal fault propagation in cemented clay. A filter paper technique was adopted to simulate the effects of a pre-existing fracture. A bending deformation mechanism was identified in cemented clay with and without the pre-existing fracture. Although the area of bending zone was reduced,the extent of damage was increased by the presence of pre-existing fracture. Observed fault ruptures could be characterized as tension cracks and shearing cracks. These ruptures provide preferential paths for dissipation of excess pore pressures generated during normal fault propagation.