(1.廣州市建筑科學(xué)研究所，廣州 510030;
2.中南工業(yè)大學(xué)，長沙 410083)
摘 要: 根據(jù)靜力學(xué)理論提出了分層非均勻土質(zhì)、變截面和非均質(zhì)樁身的復(fù)雜樁土系統(tǒng)在外荷載作用下，樁身位移滿足的微分方程和邊界條件，推導(dǎo)了線彈性和彈塑性條件下的微分方程解析解。在已知樁土力學(xué)參數(shù)的條件下，可以計(jì)算不同樁頂沉降下對應(yīng)的荷載大小與樁身相應(yīng)的內(nèi)力、摩擦阻力和端承力大小，以及樁底的位移值；也可根據(jù)實(shí)測的若干個(gè)靜荷試樁數(shù)據(jù)，通過作理論計(jì)算與實(shí)測曲線擬合分析處理，確定樁土系統(tǒng)的力學(xué)參數(shù)，然后進(jìn)一步分析樁的受力機(jī)理。工程樁靜荷試驗(yàn)和內(nèi)力測試研究結(jié)果表明，理論分析的樁底位移和實(shí)際試驗(yàn)的殘余沉降值比較吻合，計(jì)算的樁身內(nèi)力與實(shí)測內(nèi)力對應(yīng)性較好，特別是利用4000kN的靜荷載試驗(yàn)結(jié)果進(jìn)行反演擬合處理求得的樁土系統(tǒng)特性參數(shù)，推算外荷載為5200 kN 對應(yīng)的樁頂沉降值和樁底位移值，與實(shí)際5200kN靜荷載試驗(yàn)的結(jié)果很相近。
關(guān)鍵字: 樁基 分布參數(shù) 正反演問題 承載力 沉降
（1.Guangzhou Institute of Building Sciences, Guangzhou 510030
2.Central South University of Technology, Changsha 410083）
Abstract:On the basis of mechanics theory, differential equations and boundary conditions of pile displacement were put forward for the complicate pile-soil system with non-homogeneous soil and change in pile section and modulus under load on pile top. The corresponding solution was obtained under the condition of linear elasticity and elastoplasticity. With the known condition of mechanics parameters of pile-soil system, the corresponding load, the internal force along the pile axis, the frictional resistance and the bearing capacity settlement of the pile can be computed according to the settlement at pile top. On the other hand, the mechanics parameters of pile-so il system can be determined by matching the theoretical curve of load-settlement and test curve with the data of normal load test, and then the mechanism of pile performance under load can also be analysed. The comparison between theoretical research results and pile test data of load and internal force showed that calculated settlement at pile bottom well matches the residual settlement during loading test and the internal force calculated is much close to the test results . Especilly, comparing with the loading test result of 5200 kN, it can be successful to applying the parameters of pile-soil system which are analysed by matching the load ing test result of 4000 kN to compute the settlements on both top and bottom of pile under acted load of 5200 kN on pile top.
Key words: plie distribution parameter direct and inverse problem bearing capacity settlement
