岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
8期
2158-2164,2173
,共8页
孙军杰%田文通%徐舜华%刘琨%王兰民%牛富俊
孫軍傑%田文通%徐舜華%劉琨%王蘭民%牛富俊
손군걸%전문통%서순화%류곤%왕란민%우부준
黄土场地%地震动%残余应变%室内试验%动力沉降%概率性评价
黃土場地%地震動%殘餘應變%室內試驗%動力沉降%概率性評價
황토장지%지진동%잔여응변%실내시험%동력침강%개솔성평개
loess field%ground motion%residual strain%laboratory test%dynamic settlement%probability-based evaluation
天然黄土动残余应变研究主要依赖室内动三轴试验,如何将有限室内试验数据合理地应用于场地动力沉降的定量评价,是岩土地震工程领域中研究涉足尚少的重要科学问题。应用概率统计与蒙特卡洛模拟等非确定性分析方法,借助综合考虑固结应力、结构强度、空间体积特性和地震动荷载等动残余应变关键影响参量的估算模型,提出有效弱化土体物性参量不确定性(离散性与随机性)的场地动力沉降概率性评价的思路与方法。应用结果显示,利用该方法得出的场地动力沉降的概率分布特征,能够反映天然黄土动残余应变的基本认知特点,对明晰地震作用下天然黄土场地精细动力沉降特性以及据此采用适当合理的地基处理方法,具有理论意义与实用价值。
天然黃土動殘餘應變研究主要依賴室內動三軸試驗,如何將有限室內試驗數據閤理地應用于場地動力沉降的定量評價,是巖土地震工程領域中研究涉足尚少的重要科學問題。應用概率統計與矇特卡洛模擬等非確定性分析方法,藉助綜閤攷慮固結應力、結構彊度、空間體積特性和地震動荷載等動殘餘應變關鍵影響參量的估算模型,提齣有效弱化土體物性參量不確定性(離散性與隨機性)的場地動力沉降概率性評價的思路與方法。應用結果顯示,利用該方法得齣的場地動力沉降的概率分佈特徵,能夠反映天然黃土動殘餘應變的基本認知特點,對明晰地震作用下天然黃土場地精細動力沉降特性以及據此採用適噹閤理的地基處理方法,具有理論意義與實用價值。
천연황토동잔여응변연구주요의뢰실내동삼축시험,여하장유한실내시험수거합리지응용우장지동력침강적정량평개,시암토지진공정영역중연구섭족상소적중요과학문제。응용개솔통계여몽특잡락모의등비학정성분석방법,차조종합고필고결응력、결구강도、공간체적특성화지진동하재등동잔여응변관건영향삼량적고산모형,제출유효약화토체물성삼량불학정성(리산성여수궤성)적장지동력침강개솔성평개적사로여방법。응용결과현시,이용해방법득출적장지동력침강적개솔분포특정,능구반영천연황토동잔여응변적기본인지특점,대명석지진작용하천연황토장지정세동력침강특성이급거차채용괄당합리적지기처리방법,구유이론의의여실용개치。
Dynamic triaxial test in laboratory is the main approach to investigate the dynamic residual strain (seismic subsidence) of natural loess under seismic loadings. How to reasonably apply the little test data in laboratory into the quantitative evaluation of dynamic settlement in loess field is one key problem within the practice of geotechnical earthquake engineering. Based on a magnitude estimation model for dynamic residual strain of natural loess, which comprehensively considers the critical influence parameters of the dynamic subsidence, consolidation stress, structure strength, spatial volume property and seismic loadings, the authors propose a probability-based evaluation method for ground settlement of natural loess under seismic loadings by means of theoretical analysis methods of probability statistics and Monte Carlo simulation. For the application of this new probability-based evaluation method, here, we provide one practical case on a typical loess field. The relevant Chi-square test show that frequency features of the four critical parameters influencing dynamic residual strain of natural loess determined by the above-mentioned theoretical model could be described by normal distribution. In order to minimize the uncertainties (scattering and randomness) of physico-mechanical property of the soil, furthermore, Monte Carlo simulation technique is adopted to extend the laboratory data into huge numbers. Then the corresponding huge numbers of dynamic residual strain of natural loess in the case field calculated by the evaluation method could be used to analyze the probability features of dynamic settlement behaviors of the loess ground. According to occurrence probabilities of different magnitude-grades of dynamic settlement, we could acquire the detailed behaviors of dynamic residual strain of natural loess in the target field under seismic loadings. The probability distribution reveals that the quantitative evaluation method reported here can obviously decrease the influence of parameter uncertainty associated with the soil. Meanwhile, those probability characteristics of dynamic settlement in the example field accord with the existing basic-behavior knowledge of dynamic residual strain of natural loess under seismic loadings. These results mean that the probability method could provide a better/reasonable reference not only to understand dynamic settlement behaviors of natural loess ground under seismic loadings, but also to select the proper treatment method for the potentially dangerous ground.