According to the principle of foundation treatment of collapsible loess, the collapsible loess has low compressibility and high strength under natural humidity, but when it is soaked by water, the strength of the soil decreases significantly. Under the combined action of additional pressure or the additional pressure and the saturated dead weight pressure of the soil, it has the property of sudden subsidence. In THE construction OF COLLAPSIBLE loess area, it is necessary to take treatment measures for building foundation to improve the physical and mechanical properties of soil, reduce or eliminate the collapsible deformation caused by accidental flooding of collapsible yellow soil gene, and ensure the safety and normal use of buildings
Details >The SELECTION OF THE TREATMENT METHOD OF COLLAPSIBLE LOESS FOUNDATION SHOULD be based ON the type OF BUILDING, THE type OF SITE, the thickness OF COLLAPsible loess, the distribution OF COLLAPsible coefficient along the depth, the source of materials and the construction conditions, and through technical and economic analysis, so as to take measures according to local conditions and protect the environment. The common treatment methods of collapsible loess foundation can be selected according to the table.
Details >Silt soil has the characteristics of very low strength, large compressibility, poor water permeability, large thixotropy and rheological property. In the foundation treatment, there will be low bearing capacity, slow growth of strength, easy and uneven deformation after loading, large deformation rate and long stability time, which will have adverse effects on buildings. Therefore, in the foundation treatment, it is necessary to select appropriate foundation treatment technology for silt soil to ensure the quality of the project. The following are five common methods of silt soft soil foundation treatment:
Details >The foundation treatment scheme selection should follow the following principles: 1, must master enough information; 2. Technical rationality; 3. Feasibility of construction technology; 4. Economy; 5, there should be a superstructure - foundation - foundation interaction concept
Details >Weakness is refers to the soft soil ground treatment including silt, silt soil, part of the filling soil, and other miscellaneous fill high compressibility of soil, its engineering properties for high natural moisture content, natural void ratio, high compressibility, permeability coefficient, low shear strength of soil, used in bolus layer method, the method, deep mixing method, compaction grouting method, dynamic compaction method, etc.
Details >The construction plan of foundation pit excavation should comprehensively consider engineering geology and hydrogeology conditions, environmental protection requirements, site conditions, foundation pit plane size, excavation depth, support form, construction method and other factors. The highest water level and tide level should also be considered for the foundation pit near water.
Details >Foundation treatment generally refers to the artificial treatment of foundation in order to improve the bearing capacity of foundation (soil or rock), or improve its deformation property or permeability property, so as to meet the normal use function and durability requirements of buildings under long-term load.
Details >Recently, ding yuan soft foundation by the tianjin science and technology development co., LTD., zhongjian six innings of south China construction co., LTD., sponsored by the "regulations of technology of foundation reinforcement component application" (hereinafter referred to as the "rules") by the fourth working conference and China (tianjin) the second to the firmware can technology theory seminar, in tianjin tianjin lihua grand hotel was held successfully. Shanghai strong foundation, Zhengyuan Construction, South Zhejiang Geology, Tianjin University, Hohai University, Jingye Engineering, Geotechnical Engineering Survey Institute, China Construction Bureau Six, Nanjing Water Conservancy, Beijing Urban Construction and other participating units and individual members of the compilation group attended the meeting.
Details >Dynamic compaction foundation treatment design including effective reinforcement depth determination, interval time, consolidation point arrangement, processing range, etc., before construction should be in the construction site representative on the site to select one or several test areas, trial compaction or experimental construction, determine the design parameters.
Details >The method of dynamic compaction is a method that the heavy hammer of dozens of tons falls freely from the height to forcefully ram the soil. The high quality heavy hammer falls freely at a certain height and has potential energy. When it falls to the ground, compression wave and shear wave are generated to destroy the soil structure, form a closer connection of soil particles, increase the strength of the foundation, reduce the amount of deformation, improve the anti-liquefaction condition of soil, and eliminate the collapsibility of collapsible loess. Ramming can force the uniformity of the treated soil layer to increase.
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