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摘  要

現(xiàn)澆混凝土薄壁管樁（簡稱PCC樁）是由河海大學(xué)巖土工程科學(xué)研究所研發(fā)的一種新型樁型。鋼纖維混凝土是在普通混凝土中摻入不定向分布的鋼纖維以增強(qiáng)混凝土力學(xué)性能的新型復(fù)合材料。本文采用鋼纖維混凝土材料和PCC樁型，通過模型試驗探究定向鋼纖維PCC樁的水平承載特性，本文的主要工作和結(jié)論包括： 

1、設(shè)計了定向鋼纖維PCC樁模型試驗方案，利用通電螺線圈內(nèi)產(chǎn)生單向磁場的原理，制作了定向鋼纖維PCC模型樁。結(jié)果表明：通過通電線圈護(hù)筒，可以將混凝土中隨機(jī)分布的纖維實現(xiàn)定向分布，為實際工程中實現(xiàn)定向鋼纖維PCC樁提供了技術(shù)思路。

2、開展了定向鋼纖維PCC樁水平承載特性試驗，得到樁頂水平位移—荷載曲線和樁頂水平位移梯度—荷載曲線，確定了單樁的水平承載力。

3、通過控制摻量和定向兩個參數(shù)，開展多組對比試驗。試驗結(jié)果表明：在相同摻量下，定向鋼纖維PCC樁比不定向纖維PCC樁水平承載力提高10%~20%；在一定摻量范圍內(nèi)，定向鋼纖維PCC樁的水平承載力隨鋼纖維摻入量增加而提高。

關(guān)鍵詞： 定向鋼纖維；PCC樁；水平承載；模型試驗研究 

         

ABSTRACT

The cast-in-situ concrete thin-wall pipe pile (simple named PCC) is a new type of pile, developed by the Research Institute of Geotechnical Engineering of Hohai University. Steel fiber concrete is a new composite material which is incorporated into non-oriented steel fiber in normal concrete, in order to enhance mechanical properties of concrete. It’s the material of steel fiber concrete and the type of PCC pile that are used in this paper. The behaviors of the oriented steel fiber reinforced PCC pile, which subjected to lateral load have been studied in the physical model test. The main contents and conclusions are as follow：

1、Designing model test of oriented steel fiber reinforced PCC pile is used to instruct making the model of oriented steel fiber reinforced PCC pile. It’s made on the basis of principle that energizing solenoid produces oriented magnetic field. The results show that: it’s the oriented magnetic field produced by energizing solenoid that makes  the idea come true, which is that the steel fiber becomes oriented in the concrete. It provides technical ideas on oriented steel fiber reinforced PCC pile used in engineering practice.

2、The purpose of developing test study, which is on behaviors of oriented steel fiber reinforced PCC pile under lateral load, is to draw the curve of  and the curve of  , determining horizontal bearing capacity of single pile. 

3、By controlling two parameters of mixing amount and orientation, multiple sets of comparative tests have been carried out. As the test results show, the horizontal bearing capacity of oriented steel fiber reinforced PCC pile has increased by 10% to 20%, compared with non-oriented steel fiber reinforced PCC pile at the same mixing amount. In certain extent of mixing amount, horizontal bearing capacity of oriented steel fiber reinforced PCC pile will be increased with the addition of mixing amount.

Key words: oriented steel fiber；Cast-in-situ concrete thin-wall pipe pile；lateral load；model test study