OU组合型板桩在下穿地道基坑中的应用

OU组合型板桩即指将钢管桩和U形拉森板桩通过平面和立面组合形成的新桩型。与传统拉森钢板桩相比,其具有更大的刚度,可以支护的基坑深度更大。以浙江舟山地区某下穿地道的深基坑工程为例,对比分析了OU组合型板桩与型钢水泥土搅拌墙(SMW工法)的优缺点,并简要介绍了OU组合型板桩支护结构的计算方法。实践结果表明,对于地层复杂、开挖深度大于7 m的下穿地道基坑工程,OU组合型板桩支护结构的经济性和施工工期均优于型钢水泥土搅拌墙。

OU组合型板桩在地道基坑中的施工关键技术

结合工程实际,介绍了OU组合型板桩的关键施工技术,包括钢管桩加工、锁扣加工、打桩架设计、沉桩与拔桩工艺等。与传统钢板桩支护相比,OU组合型板桩具有抗弯刚度大、钢管桩长度调整灵活的特点,特别是对于开挖深度7~10m的地道式基坑,更具有性价比突出、施工工期短的优点。

OU组合型板桩支护的实用计算方法

OU组合型板桩在平面布置和立面布置上均不同于传统的等截面等长度钢板桩,无法采用传统钢板桩的计算方法进行其支护结构计算,故需要根据其特点,找出新的方法。基于此,介绍了OU组合型板桩支护的实用计算方法,并在浙江舟山地区某下穿地道深基坑中得到了实证。

OU组合型板桩围护的三维有限元分析

OU组合型板桩是指采用钢管桩(O型)和U型钢板桩通过平面组合和长短组合形成的新型板桩墙。针对某公路下穿地道的OU组合型板桩支护基坑,采用3D有限元软件对如下组合进行了数值模拟计算:1) O型桩与U型桩按O-U-O,O-U-U-O和O-U-U-U-O形式的平面组合;2) O型桩与U型桩按O-U-O的等长度组合和不等长度组合。计算得到O型桩和U型长度组合及平面组合下基坑变形的规律性认识。针对某实际下穿地道工程,有限元分析结果和实测结果进行了对比分析,论证了OU组合型板桩应用于公路下穿地道基坑的可行性。

静压线组合型板生产球墨铸铁管件工艺实践

根据静压线组合型板在实际生产球墨铸铁管件中遇到的问题,对比分析静压线组合模具生产的优缺点,并对组合模具生产过程中出现粘砂、缩孔、气孔和冷隔缺陷问题,提出有效的工艺改进措施。

Analytical model for ultimate loading capacities of continuous composite slabs with profiled steel sheets

Composite slabs with profiled steel sheet are widely applied in practical structures now. Plenty of literatures can be available about simply supported composite slabs with single span. However, continuous slabs always exist in high-rise building structures. In order to obtain the ultimate loading capacity of continuous composite slabs, the full scale test on slab specimens with high cost need to be carried out. This paper presented an analytical model for calculating the ultimate loading capacity of continuous composite slabs. Only the small-scale slide block test needed to be carried out for determining some mechanical parameters, resulting in less cost, compared with the conventional m-k test method. Various load conditions and parameters were considered in the analytical model. The comparison between test results and predicted results showed that the proposed method had enough precision. Furthermore, the simplified method was also proposed for practical design.