水科学与工程技术
水科學與工程技術
수과학여공정기술
WATER SCIENCES AND ENGINEERING TECHNOLOGY
2015年
2期
1-4,5
,共5页
粉土围坝%干湿循环%波浪荷载%抗剪强度%孔隙水压力%有效应力
粉土圍壩%榦濕循環%波浪荷載%抗剪彊度%孔隙水壓力%有效應力
분토위패%간습순배%파랑하재%항전강도%공극수압력%유효응력
silt dam%cyclic wetting-drying%wave load%shear strength%pore water pressure%effective stress
为揭示动水荷载作用下粉土围坝力学参数的变化规律,通过室内试验和数值模拟,分别研究了干湿循环及风浪影响下粉土围坝的力学响应。结果表明:原状粉土在经历2次以上干湿循环后,抗剪强度显著降低,且随干湿循环次数的增加,降低幅度逐渐减小;在周期性波浪荷载作用下,粉土围坝迎水坡产生震荡超孔隙水压力,且随时间动态累积,有效应力降低严重;孔隙水压力增大到一定值后将趋于稳定,孔压稳定时间随波浪周期的增大而增大。该结论的得出为天然粉土坝坡的短期和长期稳定性评价、揭示粉土围坝滑坡机理以及建立坝坡坍塌预测模型奠定了理论基础。
為揭示動水荷載作用下粉土圍壩力學參數的變化規律,通過室內試驗和數值模擬,分彆研究瞭榦濕循環及風浪影響下粉土圍壩的力學響應。結果錶明:原狀粉土在經歷2次以上榦濕循環後,抗剪彊度顯著降低,且隨榦濕循環次數的增加,降低幅度逐漸減小;在週期性波浪荷載作用下,粉土圍壩迎水坡產生震盪超孔隙水壓力,且隨時間動態纍積,有效應力降低嚴重;孔隙水壓力增大到一定值後將趨于穩定,孔壓穩定時間隨波浪週期的增大而增大。該結論的得齣為天然粉土壩坡的短期和長期穩定性評價、揭示粉土圍壩滑坡機理以及建立壩坡坍塌預測模型奠定瞭理論基礎。
위게시동수하재작용하분토위패역학삼수적변화규률,통과실내시험화수치모의,분별연구료간습순배급풍랑영향하분토위패적역학향응。결과표명:원상분토재경력2차이상간습순배후,항전강도현저강저,차수간습순배차수적증가,강저폭도축점감소;재주기성파랑하재작용하,분토위패영수파산생진탕초공극수압력,차수시간동태루적,유효응력강저엄중;공극수압력증대도일정치후장추우은정,공압은정시간수파랑주기적증대이증대。해결론적득출위천연분토패파적단기화장기은정성평개、게시분토위패활파궤리이급건립패파담탑예측모형전정료이론기출。
In order to reveal the change ru le of mechanical parameters of silt dam under hydrodynamic load, mechanical response of silt dam under cyclic wetting-drying and stormy waves was studied respectively through laboratory test and numerical simulation. The results showed that shear strength of undisturbed silt decreased significantly after more than 2 times of cyclic wetting-drying, and the decreasing amplitude decreased gradually with the increase of cycle number. Excess pore water pressure of silt dam upstream slope oscillated under wave load and accumulated dynamically with time, which led to decrease of effective stress seriously. The pore water pressure would tend to be stable when it increased to a certain value. The pore pressure stabilization time increased as the wave period increased. This conclusion established the theoretical foundation for stability evaluation of natural silt dam slope in short term and long-term, revealing landslide mechanism of silt dam and prediction model establishment of dam slope collapse.