空(kong)(kong)心(xin)(xin)方樁(zhuang)(zhuang)是一(yi)種(zhong)結合預(yu)應(ying)力管樁(zhuang)(zhuang)和(he)預(yu)制方樁(zhuang)(zhuang)二者的優(you)點(dian)(dian),同時克(ke)服(fu)了其(qi)大(da)部分缺點(dian)(dian)的新型(xing)樁(zhuang)(zhuang)型(xing),現國(guo)際上(如美國(guo)、日本等(deng))已大(da)力開(kai)始推(tui)廣使用.按混(hun)(hun)凝(ning)土(tu)(tu)的等(deng)級強(qiang)度(du)及混(hun)(hun)凝(ning)土(tu)(tu)承(cheng)載面(mian)的大(da)小(xiao)可分為(wei)(wei)(wei)KFZ、HKFZ、TKFZ,分別為(wei)(wei)(wei)預(yu)應(ying)力混(hun)(hun)凝(ning)土(tu)(tu)空(kong)(kong)心(xin)(xin)方樁(zhuang)(zhuang)(KFZ)、預(yu)應(ying)力高強(qiang)混(hun)(hun)凝(ning)土(tu)(tu)空(kong)(kong)心(xin)(xin)方樁(zhuang)(zhuang)(HKFZ)、預(yu)應(ying)力混(hun)(hun)凝(ning)土(tu)(tu)薄壁空(kong)(kong)心(xin)(xin)方樁(zhuang)(zhuang)(TKFZ),其(qi)中TKFZ主要(yao)用于(yu)摩擦樁(zhuang)(zhuang)為(wei)(wei)(wei)主的地質,而HKFZ主要(yao)適合于(yu)承(cheng)載力要(yao)求(qiu)較高或(huo)有高耐(nai)腐蝕要(yao)求(qiu)的地質情況,KFZ與TKFZ的混(hun)(hun)凝(ning)土(tu)(tu)強(qiang)度(du)等(deng)級為(wei)(wei)(wei)C60,HKFZ的混(hun)(hun)凝(ning)土(tu)(tu)強(qiang)度(du)等(deng)級為(wei)(wei)(wei)C80.空(kong)(kong)心(xin)(xin)方樁(zhuang)(zhuang)的外邊長主要(yao)有250*250---1000*1000,以每50為(wei)(wei)(wei)增量.相對于(yu)其(qi)它樁(zhuang)(zhuang)型(xing),特別是預(yu)應(ying)力混(hun)(hun)凝(ning)土(tu)(tu)管樁(zhuang)(zhuang)而言,其(qi)突出(chu)的優(you)點(dian)(dian)在(zai): 
    同截面混凝土(tu)下方樁外表(biao)面積大于管(guan)樁,且成方型(xing)或多邊角型(xing)的外形,在土(tu)層中樁體周邊土(tu)與土(tu)的休止角比(bi)圓型(xing)的摩阻(zu)系(xi)數(shu)要大得多.這就意味(wei)著空心方樁比(bi)管(guan)樁在同等地質條件下能獲得更大的承載(zai)力,為工程省下大量的基礎資金。