| At present,rock-socketed piles have been widely used in various important constructions,water conservancy projects and bridge engineering.However,due to different geological conditions,unstable quality of concrete and diversity of construction technology,high ultimate bearing capacity of rock-socketed piles and failure of test piles,the bearing behavior of rock-socketed piles is still not completely clear.People have different understanding of the bearing behavior of rock-socketed piles,and different regions have different understanding of the bearing behavior of rock-socketed piles.There are great differences in the calculation of bearing capacity and displacement between national codes.Although there are many studies on rock-socketed piles at home and abroad,due to the historical limitations and engineering conditions,high-quality rock-socketed piles with complete test data are rare,which greatly limits the development of rock-socketed pile theory.Because the bearing capacity and failure mechanism of piles and shallow foundations are different,the calculation of bearing capacity is also different,and the calculation results are naturally very different.When designing rock-socketed pile,rock-socketed piles are usually designed as ordinary piles,however,this design method cannot make full use of the side and end resistance of pile foundation,nor can it improve the cost performance.In this paper,through the combination of numerical simulation and test,the stress of rock-socketed piles in Hunhe Bridge under horizontal load and the design depth of rock-socketed piles are studied.The numerical analysis method is a powerful means to analyze the complex rock-socketed pile problem by means of computer solving mathematical calculation.The field load test is the most stable and direct method to study the stress mechanism of rock-socketed pile and to obtain the characteristic value characteristics of bearing capacity of pile foundation.Through a large number of literature,engineering data,the design and construction technology of embedded rock piles at home and abroad was investigated,and the geological conditions of the Hunhe Bridge,mechanical selection and other practical conditions,the development of the Hunhe Bridge test program,the two test piles base respectively carried out two on-site load tests of pile and column beams,the test measured pile body displacement,the inner force state and the surrounding soil layer force state,and then with the numerical analysis data comparison analysis,to verify the construction map of the Hunhe Bridge in the central line of Liaozhong rock depth.The results are as follows:1)According to the calculation results of relevant codes and similar engineering data,the rock socketed depth of pile foundation of Hunhe bridge is 3d-5d,the rock socketed depth of test pile is 10 m,and the pile length is 12 m.2)Using the horizontal load test scheme,the on-site loading test was carried out,and the test results showed that the reasonable embedded rock depth of the Hunhe Bridge was 6m,the pile length was 8m long,the maximum pull stress of pile concrete in the pile length range was 1.6MPa,the maximum pressure stress was 1.7MPa,and the maximum stress of the pile main ribs was 6.9 MPa.The maximum displacement of the top of the pile is 2.0mm,the maximum soil pressure is 60.0kPa,and the force of the pile body and the pile side body is in the elastic tolerance range.3)The results of numerical simulation show that the reasonable embedded rock depth of the Hunhe Bridge is 9m,the pile length is 11 m long,the maximum pull stress of pile concrete in the pile length range is 3.8MPa,the maximum pressure stress is 4.2Mpa,the maximum stress of the pile body is 21.7 MPa,and the maximum displacement of the pile top is 4.0mm.The maximum soil pressure is 90.6kPa,and the force of the pile and pile side rock body is in the elastic tolerance range. |
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