Experience with construction on long underreamed piles in collapsible soils

Conclusions 1. The noneffectiveness of construction of underreamings in long piles resting on insufficiently dense soils is due to high resistance on their lateral surfaces and small settlements until rupture occurs, as a result of which the tip resistance is not realized.2. The increase in the settlements of bored-cast-in-place piles for long-term soaking under the above-mentioned soil conditions does not depend on the external load applied to them and on the use of underreamings, for all practical purposes, but it is detemined by the laws of development of collapse depressions.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 4, pp. 2–5, July–August, 1990.     

Experience in sinking bored,underreamed piles in the Ukraine

Soil Mechanics and Foundation Engineering -     

扩体锚杆拉拔破坏的数值分析

应用岩土分析软件对竖直抗拔的扩体锚杆进行了数值分析,得到扩体锚杆锚周土的应力变化情况,分析结果表明:随加载力的增大,扩大头部分破坏体范围不断扩大,达到极限承载力后,破坏范围呈帽状且不再扩大。     

桩基础承台间连系梁设计分析

介绍了桩基础承台间连系梁的设计方法，阐述了承台间连接时连系梁的计算方法，指出设计中，在不同的条件下，应采用不同的计算模型，以使其设计更加合理。     

Design of rigid pile frame structure with interaction of piles

Soil Mechanics and Foundation Engineering -     

某住宅楼基础及边坡支护结构设计

结合长沙市某住宅楼基础的设计方案,介绍了护坡桩的设计方法,并在现有边坡边界条件不变的情况下,用住宅楼的部分基础承重桩支护边坡,达到一桩两用的效果,具有参考价值。     

马尾电信机房楼的桩基设计与施工处理

本文结合工程实例介绍设计中预应力管桩及钻孔灌注桩的比较、选用,同时对预应力管桩的两种辅助沉桩法：引孔辅助沉桩法及水冲气举辅助沉桩法进行比较、选用,总结经验,供类似工程参考。     

Design of laterally loaded piles in a nonlinearly deformable bed

Conclusions 1. The computational method that we have proposed makes it possible to study the performance of the "pile-soil" system in the elastoplastic stage and investigate the behavior of piles and pile frames in all stages of loading — right up to failure.2. Allowance for shear strains in the cross section enables us to reflect the stress-strain state of the "pile-soil" system more precisely and provide high serviceability to the pile beds.Astrakhan Technical Institute, RPKh. Far East Scientific-Research Institute for the Design and Planning of Marine Structures. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 4, pp. 9–11, July–August, 1980.     

广西某滑坡双排抗滑桩加固设计

由于施工局部堆载和降雨等不利条件的作用,在场区西侧发育一大型滑坡,局部出现抗滑桩变形破裂迹象,并有进一步发展的趋势。通过几次深入详细的勘察,查明该滑坡的破坏模式。进一步通过参数敏感性分析等手段综合选取滑坡稳定性分析的力学参数。由于计算所得滑坡推力过大,设置一排抗滑桩难以进行有效支挡。采用荷载结构法所得桩身内力分布,设置...     

太原地区钻孔灌注桩设计施工若干问题

通过对工程实例和大量的试桩结果进行分析 ,论述了太原地区钻孔灌注桩的发展过程 ,提出了在灌注桩设计施工中存在的问题并就今后的发展方向进行了展望     

Design and analyses of open-ended pipe piles in cohesionless soils

Large open-ended pipe pile has been found to be advantageous for use in transportation projects. The current design method, however, is not adequately developed. To close this practice gap, this paper first summarized different design methods for open-ended pipe piles in sandy soils. A major factor for all the design codes is to properly account for the formation and effects of soil plug. The comparison indicates that there is a large variation in the base capacity evaluation among different methods due to the complex behaviors of soil plug. To close the knowledge gap, discrete element method (DEM) was used to simulate the soil plugging process and provide insight on the plugging mechanism. The simulation results show that the arching effect significantly increases the internal unit shear resistance along pipe piles. The porosity distribution and particle contact force distribution from DEM model indicate a large stress concentration occurs at the bottom of the soil plug. Besides, nearly 90% of the plug resistance is provided by the bottom half portion of the soil column. The soil-pile friction coefficient has a significant effect on the magnitude of plug resistance, with the major transition occurred for friction coefficient between 0.3 and 0.4.     

利用短桩控制建筑物沉降设计的探讨

对于多层建筑物,在地基承载力强度满足设计要求,而持力层还较软弱,不能满足沉降变形要求时,设置刚性短复合地基,结合褥垫层技术,既提高了地基承载力,又控制了建筑物的沉降变形。通过设计探讨及施工实践,达到了预期的目的。     

承压与抗拔作用于一体的锚桩设计施工技术研究

基于气压沉箱中同时具有防突沉支承力与助沉拉反力的锚桩设计与施工研究,发现锚桩经工况分析以抗拔承载力为主控,并可根据所处边界条件与常规应用的不同,对规范中确定设计桩长和桩径的公式进行合理调整,同时考虑节省投资,引入桩底后注浆与桩侧后注浆技术。在施工过程中通过自主开发的自动控制装置控制沉箱,使锚桩承压与抗拔承载作用于一体,很好做到了防突沉与助沉控制一体化,可供相关借鉴参考。     

基坑围护排桩与地下室外墙相结合的“桩墙合一”的设计与分析

"桩墙合一"技术考虑基坑围护桩与地下室外墙共同作用作为正常使用阶段的地下室侧壁挡土结构,可减薄地下室外墙的厚度、减少基坑面积,有利于节约工程造价,节能降耗,具有良好的社会经济效益。通过工程应用考虑了"桩墙合一"技术的防水、传力构造等,并通过基坑开挖阶段、正常使用阶段、抗震等多工况进行"桩墙合一"的强度与耐久性设计计算,可作为今后类似工程设计的参考。