高地震烈度軟土預(yù)應(yīng)力管樁(PHC)樁基礎(chǔ)的抗震特性研究
發(fā)布時(shí)間:2019-03-14 08:20
【摘要】:針對(duì)高地震烈度、軟土強(qiáng)度等影響預(yù)應(yīng)力混凝土管樁(PHC)抗震性能的技術(shù)難題,展開(kāi)結(jié)構(gòu)性能試驗(yàn)、振動(dòng)臺(tái)試驗(yàn)、現(xiàn)場(chǎng)試驗(yàn)、理論分析及仿真模擬xO究,在樁身彎矩變化規(guī)律、樁土變形機(jī)理、抗震穩(wěn)定性與變形控制方法、壓彎破壞特性與質(zhì)量檢測(cè)等方面取得了突破。為預(yù)應(yīng)力混凝土管樁(PHC)抗震性能的經(jīng)濟(jì)合理設(shè)計(jì)、施工提供了科學(xué)依據(jù),為在高地震烈度區(qū)(場(chǎng)地類別為Ⅲ、Ⅳ類)預(yù)應(yīng)力混凝土管樁(PHC)基礎(chǔ)的安全使用提供了有力保障。本文主要: 1.證明了在水平力荷載作用正常使用狀態(tài)下預(yù)應(yīng)力混凝土管樁(PHC)的破壞形態(tài)是壓彎破壞,而不是剪切破壞,預(yù)應(yīng)力混凝土管樁(PHC)的抗剪破壞滯后于彎曲破壞。 2.確定了在各工況中預(yù)應(yīng)力混凝土管樁(PHC)樁身彎矩最大值的產(chǎn)生位置約為距離樁頂5~6倍的樁徑,反推原型(PHC500-AB100)發(fā)現(xiàn),在El-centro地震波作用下,樁身在El-0.2g波時(shí)尚未發(fā)生危險(xiǎn)截面的破壞,但是到El-0.3g、El-0.4g時(shí)樁身最大彎矩值都超過(guò)了規(guī)范中規(guī)定的極限彎矩值,該危險(xiǎn)截面直接決定了樁身是否處于正常工作狀態(tài),此處是預(yù)應(yīng)力混凝土管樁在抗震設(shè)計(jì)時(shí)的危險(xiǎn)截面。 3.建立并驗(yàn)證了預(yù)應(yīng)力混凝土管樁(PHC)時(shí)程分析的數(shù)值模型,仿真計(jì)算表明最大彎矩值出現(xiàn)在5倍的樁徑處,已造成預(yù)應(yīng)力混凝土管樁(PHC)的開(kāi)裂,其值已經(jīng)接近或超過(guò)預(yù)應(yīng)力混凝土管樁(PHC)的極限彎矩值。 4.在高地震烈度軟土地基中軟弱夾層的存在會(huì)增大地表位移,使樁土相對(duì)位移增加;管樁在軟弱土體中的運(yùn)動(dòng)表現(xiàn)為剪切型特性,土體越軟,樁體的水平相對(duì)位移越大。 5.為了保證預(yù)應(yīng)力混凝土管樁(PHC)在高地震烈度(場(chǎng)地類別為Ⅲ、Ⅳ類)的安全與穩(wěn)定,,首次提出了豎向承載力設(shè)計(jì)抗彎強(qiáng)度校核的設(shè)計(jì)原則;xO究發(fā)現(xiàn)通過(guò)抗彎強(qiáng)度校核的管樁基礎(chǔ)抗震設(shè)計(jì),可以排除地震風(fēng)險(xiǎn)隱患,這個(gè)原則推廣應(yīng)用后大大提高建筑物的安全性。
[Abstract]:Aiming at the technical problems affecting the seismic performance of prestressed concrete tubular pile (PHC), such as high seismic intensity and soft soil strength, the structural performance test, shaking table test, field test, theoretical analysis and simulation of xO are carried out. Some breakthroughs have been made in such aspects as the variation of pile bending moment, deformation mechanism of pile-soil, seismic stability and deformation control method, compression and bending failure characteristics and quality detection, etc. This paper provides a scientific basis for the economic and reasonable design and construction of (PHC) seismic performance of prestressed concrete pipe pile, and provides a scientific basis for the high seismic intensity area (site type 鈪
本文編號(hào):2439815
[Abstract]:Aiming at the technical problems affecting the seismic performance of prestressed concrete tubular pile (PHC), such as high seismic intensity and soft soil strength, the structural performance test, shaking table test, field test, theoretical analysis and simulation of xO are carried out. Some breakthroughs have been made in such aspects as the variation of pile bending moment, deformation mechanism of pile-soil, seismic stability and deformation control method, compression and bending failure characteristics and quality detection, etc. This paper provides a scientific basis for the economic and reasonable design and construction of (PHC) seismic performance of prestressed concrete pipe pile, and provides a scientific basis for the high seismic intensity area (site type 鈪
本文編號(hào):2439815
本文鏈接:http://www.sikaile.net/kejilunwen/sgjslw/2439815.html
最近更新
教材專著