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To improve the accuracy of predicting the bearing capacity of offshore large-diameter monopiles, the initial high strain detection and repeated high strain detection with an interval of 10-84 days were carried out on 6 large-diameter monopiles with a diameter of 7.2m-7.4m in the offshore wind field dominated by clay soil layer. The results show that the time-dependent increment of tip resistance, side resistance and the total resistance of large-diameter monopiles in the same offshore wind farm has great discreteness, and the axial force increment of monopiles has a consistent change trend. This paper puts forward the prediction interval of 95% guarantee rate of bearing capacity increment of the offshore large-diameter monopiles based on depth, which provides a basis for the design of large-diameter monopiles. [ABSTRACT FROM AUTHOR]

In order to explore the variation law of soil particle displacement and pile force around piles during penetration process, the DEM (Discrete Element Method) model is used to test the penetration of pile foundation in layered soft soil foundation. The variation law of pile penetration force, radial pressure at pile-soil interface, friction resistance at pile side, displacement field and force field between particles during penetration process is analyzed. Research shows: (1) The penetration force increases with the increase of penetration depth and pile diameter. The increase of pile diameter is beneficial to overcome the influence of unfavorable strata. (2) At the same penetration depth, with the continuous penetration of the pile body, the radial pressure gradually decreases, showing a significant degradation phenomenon. The reason for the degradation of lateral friction is essentially the degradation of the radial pressure. (3) The distribution of contact force chain in different soil layers is similar, but the range of action is different. The contact force in silt layer is obviously larger than that in silty clay layer. The compressive stress of the soil at the end of the pile transfers radially with tensile stress. With the increase of pile diameter, the compressive stress and tensile stress in soil layer are gradually increasing, and the influence range of compressive stress and tensile stress is also gradually increasing. (4) The displacement of the soil below the pile tip is triangular, and the soil at the pile tip is squeezed around under the action of the pile tip. The influence range of particle displacement in each soil layer is different, and the influence range of particle displacement in silt layer is obviously smaller than that in silty clay layer. [ABSTRACT FROM AUTHOR]

In order to explore the relationship between the critical bearing capacity and settlement of closed pile tip pierced into the soil, based on the Boussinesq solution and the Kelvin solution, the analytical solution between the critical bearing capacity and the critical settlement of the closed pile tip is derived by combining the stress distribution function. The analytical solution of critical bearing capacity and settlement of pile tip is verified by field test of static pressure pile penetrating into layered soil with a full-section pressure sensor installed at pile tip. The results show that during the penetration process, the bearing capacity increase stage of the pile tip is divided into linear steepening section and nonlinear slow increasing section. The soil in the linear steep increase section behaves as an elastic state. The bearing capacity of the pile tip before the punctured soil layer is linear with the settlement, and the final value of the linear steep increase section is the elastic limit value and the critical bearing capacity of the piercing pile tip. When the residual pile tip force is not considered, the critical settlement of the pile tip is between 0.095-0.119d; when considering the residual pile tip force, the critical settlement is between 0.091-0.105d. In particular, when the Poisson's ratio is 0.5, the analytical solution of the semi-infinite space is equivalent to the analytical solution of the infinite space. [ABSTRACT FROM AUTHOR]

At present, the construction industry is in urgent need of a big transformation from the traditional extensive development model to achieve transformation and upgrading. The cooperative application mode of lean construction and BIM is the important driving method of this change. It effectively solved the information technology problems in the process of lean construction implementation. Meanwhile, the lean construction system also provides a better application environment for BIM and fully realizes the technical value. From the perspective of multiple applications, this paper introduces in detail how BIM uses its technical advantages to enhance the application value of lean construction in the construction industry. [ABSTRACT FROM AUTHOR]

In the construction process of high-rise building structure, the formwork temporary supports and the concrete structure are considered as a whole. Quantifying the load under the template supports can provide a better reference for the design of the template supports. In order to study the load transfer law between formwork support scaffolds and multi-storey structure, through the installation of sensors at the bottom of formwork supports and the floor slab, the load transfer law of the 3 adjacent formwork supports were monitored for a long time during the construction of highrise buildings via the high-frequency wireless transmission systems. The main conclusions are as follows: (1) The monitoring data shows that the most unfavourable load occurs when concrete is poured into the upper story, about 1.9 times the axial force generated when concrete is poured into the test floor. (2) The monitoring data has a similar shape which is summed up as an ideal curve of change, 3 times of peak value, 3 times of decline and 1 time of sudden drop. (3)The transfer ratio of load accounts for about 57% ~ 69% of a total load of fresh concrete. (4) Considering the fluidplastic state of concrete, a correction factor of 1.22 for vertical pole axial force is proposed, and the deviation between the modified simulated value and the measured value is less than 3%. [ABSTRACT FROM AUTHOR]