铁道建筑
鐵道建築
철도건축
RAILWAY ENGINEERING
2015年
8期
27-31
,共5页
张文学%陈壮%刘龙%许成顺
張文學%陳壯%劉龍%許成順
장문학%진장%류룡%허성순
桩基%沉降%溶洞%线溶率
樁基%沉降%溶洞%線溶率
장기%침강%용동%선용솔
Pile foundation%Subsidence%Karst cave%Linear karst ratio
新建铁路客运专线设计时速多为300 km以上,对桥梁桩基沉降量要求极高。全面分析岩溶区溶洞对桩基沉降的影响,准确预测岩溶区桩基的沉降量是铁路客运专线桥梁基础设计的难题。以郑徐铁路客运专线徐州特大桥岩溶区桩基工程为依托,通过建立桩基和溶洞地基有限元模型,系统分析了溶洞参数对桩基沉降的影响规律,并对比了不同注浆加固方案对岩溶区桩基沉降的控制效果。结果表明:溶洞顶板厚度、桩尖至岩溶层间岩土层厚度、溶洞尺寸大小及竖向线溶率均对桩基沉降有影响。其中,桩尖至岩溶层间岩土层厚度和溶洞顶板厚度对注浆加固效果影响较大,应根据具体情况进行分析以确定合理的注浆加固方案。
新建鐵路客運專線設計時速多為300 km以上,對橋樑樁基沉降量要求極高。全麵分析巖溶區溶洞對樁基沉降的影響,準確預測巖溶區樁基的沉降量是鐵路客運專線橋樑基礎設計的難題。以鄭徐鐵路客運專線徐州特大橋巖溶區樁基工程為依託,通過建立樁基和溶洞地基有限元模型,繫統分析瞭溶洞參數對樁基沉降的影響規律,併對比瞭不同註漿加固方案對巖溶區樁基沉降的控製效果。結果錶明:溶洞頂闆厚度、樁尖至巖溶層間巖土層厚度、溶洞呎吋大小及豎嚮線溶率均對樁基沉降有影響。其中,樁尖至巖溶層間巖土層厚度和溶洞頂闆厚度對註漿加固效果影響較大,應根據具體情況進行分析以確定閤理的註漿加固方案。
신건철로객운전선설계시속다위300 km이상,대교량장기침강량요구겁고。전면분석암용구용동대장기침강적영향,준학예측암용구장기적침강량시철로객운전선교량기출설계적난제。이정서철로객운전선서주특대교암용구장기공정위의탁,통과건립장기화용동지기유한원모형,계통분석료용동삼수대장기침강적영향규률,병대비료불동주장가고방안대암용구장기침강적공제효과。결과표명:용동정판후도、장첨지암용층간암토층후도、용동척촌대소급수향선용솔균대장기침강유영향。기중,장첨지암용층간암토층후도화용동정판후도대주장가고효과영향교대,응근거구체정황진행분석이학정합리적주장가고방안。
As most of the newly constructed passenger-dedicated railway lines operate at 300 km/h or above, foundation subsidence of bridge piles stands as a critical challenge. T herefore,how to thoroughly analyze the influence of karst cave to pile subsidence,and how to predict pile subsidence in an accurate manner stand as two difficult tasks to the foundation design for passenger-dedicated railway bridge. T he paper takes the pile foundation of Xuzhou super-long bridge on Zhengzhou-Xuzhou passenger-dedicated railway line as the study object,and builds finite-element model for the analysis of pile foundation and karst-cave foundation accordingly. It looks into the karst parameters and its influence on foundation subsidence,and gives the comparative results of different grouting schemes. T he results indicate that relevant factors include thickness of head lining,thickness of rock-soil layer ( from pile tip to karst layer ) ,cave dimension and linear karst ratio in vertical direction. It needs to be noted that comparatively,the first two exert the greatest influence on grouting results,therefore the grouting scheme applied shall be based on concrete conditions.