长螺旋钻孔压灌空心桩(夹芯桩)成桩技术研究

RESEARCH ON PILE-FORMING TECHNOLOGY OF LONG SPIRAL DRILLING PRESS-GROUTING AND IRRIGATION HOLLOW PILE(SANDWICH PILE)

长螺旋钻孔空心桩(夹芯桩)是-种新型变截面现浇混凝土复合桩体。由于砂石混合泥浆对新浇混凝土筒壁进行了有效护壁,拔管后则形成连续施工的夹芯桩;后沉管扩大了原桩径,提高了单桩承载力;就地利用余土制成砂石混合泥浆回灌,节约了混凝土、减少了余上外运和污染;因单桩承载力增大,原多桩受力承台下的桩数量将减少,其承合体量相应缩小等。其结构合理、综合效益显著。

Long spiral drilling press-grouting and irrigation hollow pile(sandwich pile)is a new type of cast-in-place concrete composite pile with variable section.Due to the sand and stone mixed mud has effectively protected the wall of the newly casted concrete cylinder,the sandwich pile which is continuous construction is formed after the pipe is pulled out.The rear-sinking pipe enlarges the pile diameter and improves the bearing capacity of single pile.In-place use of redundant soil to make mixed sand and stone mud is refilled into the pipe.It saves concrete and reduces the transport of redundant soil to the outside and pollution.Because the bearing capacity of single pile increases,the number of piles under the bearing cap of the original pile will be decreased,correspondingly its pile cap volume decreased and so on.Its structure is reasonable and its comprehensive benefit is dramatic.