城市建设中大面积荷载作用的影响深度探讨

随着工程建设规模的扩大,围海造地、码头堆场、堆载预压等填方工程的面积越来越大,它们都属于大面积荷载问题。在城市建设中,建筑物荷载的累加效应也具有大面积荷载的性质。通过对城市工程建设与大面积荷载关系的揭示,对大面积荷载的特征及其对地面沉降的影响进行初步定义和分析。大面积荷载对变形的影响深度大于一般建筑物的影响深度,但小于按常规方法计算得到的结果。在对发生这种情况的可能原因分析的基础上,对人们所发现的上海地区城市建设与沉降的关系,如建筑密度越大,建筑容积率越高,地面沉降越显著,新区建设较旧城改造沉降效应明显等,给予较好的解释。同时得出,容积率一定的情况下,高层建筑由于密度小,间距大,将会比密集的多层建筑更有利于减小整体地面沉降等结论。有关分析对城市建设规划会有所帮助。

DISCUSSION ON INFLUENCE DEPTH OF LARGE-SCALE LOAD IN URBAN CONSTRUCTION

With the development of construction, such engineering activities as beach reclamation, ore stacking and preloading act are becoming much bigger than before. They will bring large-scale load and related problems. It is the same with the buildings in cities, which also has the characteristics of load with large-scale. It was investigated the relationship between city buildings and large-scale equivalent effeeting load, and discussed primarily its effect on land subsidence. The influence depth of large-scale load is bigger than routine building load, but is smaller than the one calculated by routine methods, whose reason is interpreted. It is found that land subsidence is related to city construction in Shanghai. Bigger subsidence is induced in new area construction than old inhabited area, and bigger building density and bigger volumetric fraction caused bigger subsidence. These phenomena can be well understood according to the paper. As a result, the conclusion is drawn that with smaller density and bigger spacing, a high-rise building will be more useful in reducing land subsidence than a low-rise building, which is thought to be helpful for urban planning.