CAJ | 학술논문

利用微型钢管桩托换支撑既有建筑，下方开挖土方施工地下室是一种既有建筑地下增层的有效方法。但随着钢管四周土方的开挖，钢管稳定性会降低。文章对位于济南商埠区的济南某医院地下增层工程进行了设计，并对钢管稳定性的保证措施进行了研究。结果表明：每向下开挖一定深度需在钢管间设置拉结支撑杆件，钢管两侧挖土的高差应控制在1.5 m 之内，以减少钢管承担的土压力；钢管桩插入钻孔后，需要在孔壁与钢管间高压注浆，形成对钢管的约束和嵌固；钢管的计算长度系数应根据桩顶的约束情况、桩身露出地面的自由长度、桩的入土长度、桩侧和桩底的土质等条件综合确定；钢管受压稳定性系数为0.814，压应力为46.4 N/ mm2，远小于强度设计值215 N/ mm2。
이용미형강관장탁환지탱기유건축，하방개알토방시공지하실시일충기유건축지하증층적유효방법。단수착강관사주토방적개알，강관은정성회강저。문장대위우제남상부구적제남모의원지하증층공정진행료설계，병대강관은정성적보증조시진행료연구。결과표명：매향하개알일정심도수재강관간설치랍결지탱간건，강관량측알토적고차응공제재1.5 m 지내，이감소강관승담적토압력；강관장삽입찬공후，수요재공벽여강관간고압주장，형성대강관적약속화감고；강관적계산장도계수응근거장정적약속정황、장신로출지면적자유장도、장적입토장도、장측화장저적토질등조건종합학정；강관수압은정성계수위0.814，압응력위46.4 N/ mm2，원소우강도설계치215 N/ mm2。
Steel tubular pile underpinning technology is an effective method to develop underground space in retrofitting existing buildings. The stability of the pile under compressed load decreased after the soil around the pile dug. In this paper,the adding basement of Jinan Skin Disease Hospital in commercial port was designed and the stability of the steel tubular piles was studied. The measures of keeping the stability of piles include:installing structural connect components among the piles after certain depth soil dug,limiting the surmount of soil in 1. 5m beside the piles to decrease the soil pressure on the pile,casting cement paste into the gap between the tube and soil after steel tube is inserted in the drill hole. The effective length factor for stability calculation should be based on restricted ability of the pile top edge,free length,pile depth in soil,side and base resistance of pile. The effective length factor for pile stability calculation is 0. 814. The compressive stress of pile is 46. 4 N/ mm2 ,less than the design stress of 215 N/ mm2 .