Different Loading Methods In The Application Of The Composite Foundation Static Load Test

At present, foundation bearing force detection method has a lot of, like static load test, dynamic load test, vane shear test, static cone penetration test, field shear test, standard penetration test and rock mass in situ stress measurement etc.. Each test method is different from the foundation type and the foundation is different. In the detection of force bearing capacity of composite foundation, at present the most popular, the most intuitive, most reliable to is a static load test, because the test process and actual foundation compressive stress are basically the same, can accurately detect foundation bearing capacity of the true level. So in specification standard "(GB 50021- 2001) investigation of geotechnical engineering", the code for design of building foundation [2](GB 50007-2011), the rock soil static load test procedures in the "[3](YS 5118-2000) and so on have been listed for foundation bearing force detection of the recommended method.For the static load test, according to the length of each level of load duration, and foundation settlement under different load stability, is divided into settlement relatively stable method(slow) and settlement of non stable method(rapid method). In the detection of foundation bearing capacity, in some foreign countries maintain load method with relatively relaxed standards, lasting at least 1 hour, settlement of the relative stability of the standard is more relaxed, equivalent to China’s current rapid method. In the relevant codes of our country, it is generally recommended to adopt the slow method, only in the region of regional experience, with the slow method to adopt the fast method.The slow speed method is a waste of time and manpower.. The detection of a detection process often lasts from 1 to 2 days, and in actual engineering, it not only increases the economic costs, but also easily lead to some unnecessary errors.. And fast method because each load only need to maintain 1 hours, the general detection process in about 12 hours, easy to engineering operation. And in the actual operation, most of the operators also choose to adopt the fast method, and did not strictly follow the requirements of the slow method.Whether quick method can replace the slow method, this is a problem that has been studied and explored in the industry.. Firstly relevant norms, theory and practice, settlement of four aspects of the relationship between size and duration of compression curve of, the rapid method instead of slow method of feasibility analysis, it is concluded that the positive results. And combined with engineering example study in lime soil pile composite foundation foundation bearing force detection in fast and slow method of detection data, p-s curve analysis, summed up to modify the method for rapid method for the slow method. Through the regression analysis, the regression equation of the differential settlement difference between fast and slow method and the load value is established, and the settlement of the fast method under different loads is amended as the settlement of the slow method under different loads..Through this comparative study, it shows that the empirical formula can be used in the detection of lime soil pile composite foundation bearing capacity of foundation, rapid correction is slow. This will greatly shorten the bearing capacity of the detection time, and bring obvious economic and social benefits. It is hoped that this conclusion can bring reference and convenience for the relevant personnel in the future detection.