Qingdao foundation settlement


1. What isQingdao foundation settlement

1 Introduction

Foundation settlement refers to the settlement of foundation caused by foundation compaction under the action of additional stress. Excessive settlement, especially uneven settlement, will lead to inclined cracks and abnormal use of the building.

2.Qingdao foundation settlementclassification

The settlement of building foundation under long-term load can be divided into initial settlement (or instantaneous settlement), primary consolidation settlement (consolidation settlement) and secondary consolidation settlement.

Initial settlement

Initial settlement is also called instantaneous settlement, which refers to the settlement in saturated soft soil when the pore water is not drained. The soil will deform only if it does not deform. This kind of deformation is usually called shear deformation and is calculated by elastic deformation. For saturated soft soil foundations, especially warehouses and oil tanks, the initial settlement caused by the load should be estimated. High-rise buildings with large temporary or live loads.

Primary consolidation settlement

The primary consolidation settlement refers to the settlement of the external load over time in the process of removing the pore water of the foundation soil after the load is applied to the foundation. It starts from the time the load acts on the foundation, reaches the maximum value of the pore water pressure caused by the load, and it disappears completely. The secondary consolidation settlement is the main component of the foundation settlement. The second consolidation settlement can be carried out before the consolidation settlement is stable. Only after the primary consolidation is completed (the degree of consolidation reaches 100%), can it be regarded as secondary consolidation settlement.

Secondary consolidation settlement

Under normal circumstances, the settlement of the secondary consolidation is much smaller than that of the primary consolidation and can be ignored. However, when very soft clay soils, such as silt, silt, especially organic matter containing humus, or deep-layer highly compressible soils, the secondary consolidation settlement can be ignored. When the pressure increase is low, the secondary consolidation settlement It will be the main part of the total settlement, which needs to be paid attention to.