混合基础型式在高层建筑基础设计中的应用

人们常用的基础类型有天然基础、桩基础、筏板基础以及桩筏基础等.在基础选型时必须考虑建设场地的地质状况、上部结构的类型、施工条件、使用要求,同时还应考虑施工周期,工程投资等综合因素.通过对上述影响基础设计的因素进行分析,探讨混合基础型式在高层建筑基础设计中的实际应用.     

Analysis and Performance of Piled Rafts Designed Using Innovative Criteria

In this paper the main criteria adopted for the design and some aspects of the observed behavior of the piled foundations of a cluster of circular steel tanks are reported. They were designed to store sodium hydroxide, a toxic liquid with a unit weight of 15.1?kN/m3. Shallow foundations would have been safe against a bearing capacity failure, while the predicted settlement was beyond the allowed limit. Accordingly piles were designed to reduce the settlement and improve the overall performance of the foundations. While conventional capacity based design approach led to a total of 160 piles to support the five tanks the settlement based design approach led to a total of 65 piles achieving significant savings on the cost of the project. The settlements of four out of the five tanks were measured and for two out of the five tanks the load sharing among the raft and the piles was also observed. Both the analyses carried out at the design stage and the back-analyses of the observed behavior were based on the interaction factors method as implemented in the computer code NAPRA [Russo (1998), Int. J. Numer. Anal. Methods Geomech., 22(6), 477–493].     

核电站反应堆厂房筏基整体浇筑裂缝控制

以红沿河核电站反应堆厂房筏基整浇为工程实例,对CPR1000堆型核岛反应堆厂房筏基整体一次性浇筑实施进行了介绍,从混凝土原材料、入模温度、应变及温度监测、增设钢筋网等方面对大体积混凝土结构的裂缝控制与预防进行了分析。实践证明,这些措施保证了核岛筏基混凝土整体浇筑的工程质量,为类似工程提供了借鉴。     

某高层建筑筏板基础大体积混凝土施工技术

主要介绍了高层建筑平板筏板基础大体积混凝土施工前的温控计算，以及施工过程中采取的设计构造措施、材料措施、施工措施，并对施工现场混凝土温度进行了测量。     

利用OpenGL技术实现科学计算可视化

利用OpenGL与C＋＋Builder的接口，开发出了三维计算可视化系统，可动态地建模，计算、显示浮筏隔振装置设计的全过程。     

RBFT:基于Raft集群的拜占庭容错共识机制

针对现有联盟链共识机制因可拓展性不足,无法在支持大规模网络的同时满足低时延、高吞吐量和安全性的问题,采用网络分片的思想,提出一种适用于联盟链的带有监督节点的两级共识机制——RBFT。首先对网络节点进行分组,组内采用改进的Raft机制进行共识,然后由每个组内选出的领导者组成网络委员会,网络委员会内部采用PBFT机制进行共识。研究结果表明,在大规模网络环境下,相比PBFT和Raft,RBFT在具备拜占庭容错能力的同时可以保证高共识效率,因而具有更高的扩展性。     

Design Strategies for Piled Rafts Subjected to Nonuniform Vertical Loading

The piled raft is a geotechnical composite construction, consisting of the three elements piles, raft, and soil, which is applied for the foundation of tall buildings in an increasing number. In a parametric study, 259 different piled raft configurations have been analyzed by means of three-dimensional elastoplastic finite element analyses. In the study, the pile positions, the pile number, the pile length, and the raft-soil stiffness ratio as well as the load distribution on the raft has been varied. In the scope of this paper, the results of the parametric study are presented and design strategies for an optimized design of piled rafts subjected to nonuniform vertical loading are discussed.     

Berechnung einer Kombinierten Pfahl‐Plattengründung am Beispiel des Hochhauses “Skyper” in Frankfurt/Main

Am Bespiel des Hochhauses “Skyper” wurden durch den Unterausschuss “Kombinierte Pfahl‐Platten‐ und Pfahlgruppengründungen” des DIN verschiedene Berechnungsverfahren zur Berechnung einer Kombinierten Pfahl‐Plattengründung angewendet. Die Ergebnisse werden verglichen und diskutiert, wobei sich für den vorliegenden Fall herausstellte, dass sowohl numerische Verfahren als auch vereinfachte Verfahren, die auf der Halbraumtheorie basieren, akzeptable Ergebnisse liefern. Für eine Auswahl der geotechnischen Berechnungsverfahren wurden Federmodelle für die Abbildung der Reaktion der Baugrundoberfläche und der Pfähle abgeleitet und mit Ansatz dieser Federmodelle die Fundamentplatte bemessen. Auf dieser Grundlage gibt der Unterausschuss eine Empfehlung zur Anwendung von Berechnungsverfahren. Calculation of a piled raft foundation as a case study for the high rise building “Skyper” in Frankfurt/Main. Various calculation methods were applied on the piled raft foundation of the high rise building ”Skyper“. The results are compared and discussed. Numerical methods as well as simplified methods based on the elastic half space theory lead in the actual case to reasonable results. With the derived subgrade reaction modulus and pile stiffness the raft reinforcement was computed. A recommendation for the application of numerical and simplified methods is given.     

高层住宅基础设计实例

本文详细介绍了该工程的整个基础设计过程 ,针对该场地的地质情况 ,对主楼、地下室车库分别采用了桩基和片筏基础 ,并介绍了基坑支护方案。     

浮筏隔振系统的非共振响应分析

建立了筏架和基础板均为弹性体的浮筏动力学方程,分析了隔振器的非线性刚度对系统动态特性的影响。在线性条件下,通过刚柔耦合软件仿真,验证了建模理论的合理性,并通过功率流方法,对结构能量的传递进行了分析。在非线性条件下,隔振器具有立方非线性的刚度项,利用多尺度法研究系统发生内共振等条件,同时通过数值方法计算分析了系统在单频和多频激励下的非共振响应。研究结果表明:线性和非线性条件下的柔性浮筏隔振系统,其动力学特性区别明显。非线性条件下,筏架的刚柔程度显著地影响系统特性,而线性条件下的低频段,该影响较小。同时非线性条件下的系统存在较为复杂的谐波及倍周期现象。