南京长江二桥南汊桥塔基主要工程地质问题与力学参数的确定

MAIN PROBLEMS AND DETERMINATION OF FOUNDATION STRENGTH OF PIER OF THE SECOND NANJING BRIDGE

Investigation and Survey Bureau of the Changjiang River Water Resources Committee, Wuhan 430010, China

摘要: 南京长江二桥南汊桥塔基主要工程地质问题是岩石的强度问题. 由于塔基岩石为胶结差的砾岩与砂砾岩, 且结构和颗粒不均匀, 勘探中取样极为困难, 加之岩石常规试验的不适宜性, 使得岩石力学强度问题复杂化. 为此勘察期间对塔基岩石工程地质特性进行了较全面的研究, 并结合类似岩石的原位试验对比分析, 确定了符合本大桥的力学参数建议值, 为桩基的优化设计提供了可靠依据.
- 塔基 /
- 岩石强度 /
- 力学参数 /
- 南汊桥
Abstract: The rock strength is one of the main problems related to the pier foundation of the second Nanjing bridge across the Changjiang River. Poor cementation of conglomerate with sandy conglomerate and wide range of gravel diameters make it difficult to sample and to test by the conventional methods. A thorough geological investigation having been carried out and field tests conducted some mechanical parameters are suggested in this paper. Our work has provided a dependable basis for optimization design of the bridge piers.
- pier /
- rock strength /
- mechanical parameter /
- the second Nanjing bridge

图 1 承载力p-变形ω关系曲线

Fig. 1. Variation curves between load-bearing p and deformation ω

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图 2 桩周摩阻力试验压力p与沉降S关系曲线

Fig. 2. Variation curves between loading p and subsidence S shown by pier surface friction test

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表 1 南、北塔墩区岩体风化厚度与实测声波平均值

Table 1. Weathered rock thickness and average sound velocity around south and north pier foundation of the second Nanjing bridge across the Changjiang River

表 2 桩周摩阻力试验成果

Table 2. Results of pier surface friction test

表 3 南汊桥塔基岩石力学参数前、后建议值

Table 3. Original and verified suggested mechanical parameters of pier foundation of the second Nanjing bridge