(1. 中南大學(xué) 資源與工程安全學(xué)院，長(zhǎng)沙 410083；
2. 成都理工大學(xué) 地質(zhì)災(zāi)害防治和地質(zhì)環(huán)境保護(hù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，成都 610059；
3. 湖南省交通規(guī)劃勘察設(shè)計(jì)院，長(zhǎng)沙 410008；
4. 解放軍理工大學(xué) 國(guó)防工程學(xué)院，南京 210007)
摘 要: 利用響應(yīng)面方法開(kāi)展橫向荷載下斜坡樁的可靠性研究。引入一種考慮斜坡效應(yīng)的新型載荷-位移(p-y)曲線方法模擬斜坡上橫向受荷樁樁-土作用系統(tǒng)，采用斜坡樁樁頂位移和樁身彎矩作為功能準(zhǔn)則，建立樁頂位移失效和樁身最大彎矩兩種失效模式下橫向荷載作用斜坡樁基的可靠性分析方法，利用蒙特卡羅法驗(yàn)證了斜坡地面上橫向受荷樁的可靠性分析方法。討論橫向荷載作用下斜坡樁基可靠性的影響因素。結(jié)果表明，樁頂位移的變異性隨著極限承載因數(shù)(Npu)、50%水平的彈性模量(E50)和水平荷載(H)變異系數(shù)的增加而增加，Npu和無(wú)量綱系數(shù)(λ)的負(fù)相關(guān)關(guān)系使樁頂位移概率密度函數(shù)(PDF)值的分散性降低；相反，Npu和λ的正相關(guān)關(guān)系使樁頂位移的PDF值產(chǎn)生較大變化。對(duì)于地面水平極限承載因數(shù)(Npo)和λ，Npo和λ之間的正相關(guān)關(guān)系和負(fù)相關(guān)關(guān)系均使樁頭位移的PDF值產(chǎn)生較大變化，并且Npo和λ之間的負(fù)相關(guān)關(guān)系會(huì)明顯增加這種變異的響應(yīng)。
關(guān)鍵字: 側(cè)向受荷樁；響應(yīng)面法；概率；可靠性分析
（1. School of Resources and Safety Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,
Chengdu University of Technology, Chengdu 610059, China;
3. Huan Provincial Communications Planning Survey & Design Institute, Changsha 410008, China;
4. College of Defence Engineering, PLA University of Science and Technology, Nanjing 210007, China）
Abstract:Response surface method is used to study the reliability analysis of laterally loaded piles in sloping ground. A development load-displacement (p-y) curve for laterally loaded pile response in sloping ground is used to model the pile-soil system, both the pile head displacement and the maximum bending moment of the piles are used as the performance criteria in this study. The reliability analysis method of the laterally loaded pile in sloping ground under the pile head displacement and the maximum bending moment failure modes is proposed, which is in good agreement with the Monte Carlo method. The influences on the probability index of failure by a number of parameters are discussed. It is shown that the variability of pile head displacement increases with the increase in the coefficients of variation of ultimate bearing capacity factor (Npu), secant elastic modulus at 50% (E50) and level load (H). A negative correlation between Npu and non-dimensional factor (λ) leads to less spread out probability density function (PDF) of the pile head displacement; in contrast, a positive correlation between Npu and λ gives a great variation in the PDF of pile head displacement. As for bearing capacity factor on ground surface (Npo) and λ, both negative and positive correlations between them give a great variation in the PDF of pile head displacement, and a negative correlation will obviously increase the variability of the response.
Key words: laterally loaded pile; response surface method; probability; reliability analysis
