岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2014年
7期
1871-1877
,共7页
鲁先龙%乾增珍%童瑞铭%郑卫锋
魯先龍%乾增珍%童瑞銘%鄭衛鋒
로선룡%건증진%동서명%정위봉
戈壁%扩底基础%归一化荷载-位移曲线%抗拔%双曲线模型
戈壁%擴底基礎%歸一化荷載-位移麯線%抗拔%雙麯線模型
과벽%확저기출%귀일화하재-위이곡선%항발%쌍곡선모형
gobi%belled piers%normalized load-displacement curve%uplift%hyperbolic model
在甘肃和新疆7个戈壁碎石土场地完成了46个扩底掏挖基础抗拔现场试验,分析了基础抗拔荷载-位移曲线的阶段特征,应用L1-L2方法确定了所有基础抗拔承载力和位移。采用归一化荷载-位移双曲线模型对实测荷载-位移曲线进行拟合,得到了各试验基础归一化荷载-位移双曲线模型拟合参数取值及其统计规律,给出了同时考虑抗拔基础极限承载力计算理论模型误差和归一化荷载-位移双曲线模型不确定性时基础荷载和位移的计算方法。结果表明:戈壁碎石土扩底掏挖基础抗拔荷载-位移曲线呈初始弹性直线段、弹塑性曲线过渡段和直线破坏的3阶段变化规律,归一化荷载-位移双曲线模型可较好拟合基础实测荷载-位移曲线,归一化荷载-位移双曲线模型不确定性可转化为该双曲线模型拟合参数的不确定性,基于强度和变形统一的工程设计更有利于工程安全。
在甘肅和新疆7箇戈壁碎石土場地完成瞭46箇擴底掏挖基礎抗拔現場試驗,分析瞭基礎抗拔荷載-位移麯線的階段特徵,應用L1-L2方法確定瞭所有基礎抗拔承載力和位移。採用歸一化荷載-位移雙麯線模型對實測荷載-位移麯線進行擬閤,得到瞭各試驗基礎歸一化荷載-位移雙麯線模型擬閤參數取值及其統計規律,給齣瞭同時攷慮抗拔基礎極限承載力計算理論模型誤差和歸一化荷載-位移雙麯線模型不確定性時基礎荷載和位移的計算方法。結果錶明:戈壁碎石土擴底掏挖基礎抗拔荷載-位移麯線呈初始彈性直線段、彈塑性麯線過渡段和直線破壞的3階段變化規律,歸一化荷載-位移雙麯線模型可較好擬閤基礎實測荷載-位移麯線,歸一化荷載-位移雙麯線模型不確定性可轉化為該雙麯線模型擬閤參數的不確定性,基于彊度和變形統一的工程設計更有利于工程安全。
재감숙화신강7개과벽쇄석토장지완성료46개확저도알기출항발현장시험,분석료기출항발하재-위이곡선적계단특정,응용L1-L2방법학정료소유기출항발승재력화위이。채용귀일화하재-위이쌍곡선모형대실측하재-위이곡선진행의합,득도료각시험기출귀일화하재-위이쌍곡선모형의합삼수취치급기통계규률,급출료동시고필항발기출겁한승재력계산이론모형오차화귀일화하재-위이쌍곡선모형불학정성시기출하재화위이적계산방법。결과표명:과벽쇄석토확저도알기출항발하재-위이곡선정초시탄성직선단、탄소성곡선과도단화직선파배적3계단변화규률,귀일화하재-위이쌍곡선모형가교호의합기출실측하재-위이곡선,귀일화하재-위이쌍곡선모형불학정성가전화위해쌍곡선모형의합삼수적불학정성,기우강도화변형통일적공정설계경유리우공정안전。
The field tests of 46 uplift-loaded belled piers were carried out at 7 gobi gravel sites in Gansu and Xinjiang, respectively. Based on the characteristics of the measured load-displacement curves, the L1-L2 method was used to obtain the ultimate bearing capacities and corresponding displacements. In addition, a normalized hyperbolic equation was applied to fit the measured load-displacement data. Accordingly, the fitting parameters of hyperbolic curve were provided and analyzed. A method was suggested for determining the allowable displacement and corresponding load by considering the uncertainties in the ultimate capacity model and the normalized load-displacement hyperbolic model. The uplift load-displacement curves of belled piers in gobi could be simplified to a generic load-displacement curve with three distinct stages:an initial linear stage, a nonlinear transition stage, and a final linear failure stage. The normalized load-displacement hyperbolic equation could be used effectively to fit the measured load-displacement data. The uncertainty in the normalized load-displacement hyperbolic curve could be studied by the corresponding fitting parameters of hyperbolic curve. The method to determine the allowable displacement and corresponding load would be more safety by considering capacity and displacement together.