Research On Deep Horizontal Displacement Measurement Method Based On Fixed Inclination Sensor

Among the existing deep horizontal displacement measurement methods of foundation pit supporting structure,the fixed deep horizontal displacement measurement method has the advantages of high test efficiency and low test cost after installation,but due to the lack of theoretical basis between measurement points and the complex installation,the application of this method is restricted.This article in view of the existing fixed deep horizontal displacement measurement method shortcomings,according to the principle of subsection superposition method and accuracy analysis based on monte carlo method principle,proposed the distance between the point and the theoretical basis of the analysis process,and puts forward new connections between dip pipe and Angle sensor method,solve the problem of its installation complex.The main research and work contents of this paper include the following aspects:(1)The importance of deep horizontal displacement monitoring and the introduction of existing measurement methods.This paper reviews the development of deep horizontal displacement measurement methods at home and abroad,introduces the traditional deep horizontal displacement measurement methods,and analyzes their shortcomings.(2)The principle of subsection superposition method for measuring deformation by inclination sensor is introduced,and the feasibility of vertical displacement measurement by inclination sensor is verified by simply supported steel beam test in laboratory.The deformation forms and rules of the supporting structure of the foundation pit are discussed,and in view of the single arc deformation form and "bow" shape deformation form commonly exist in the deep horizontal displacement of the foundation pit,the comparative test of deep horizontal displacement in the laboratory is designed to verify the feasibility of measuring the deep horizontal displacement of the dip sensor.(3)Introduce the error analysis method of deep horizontal displacement measured by fixed dip sensor.Firstly,the analysis method of deformation measurement error of fixed inclination sensor is studied,including the influence of segment error(sensor number)on deformation measurement error,the influence of Angle measurement error(sensor accuracy)on deformation measurement error,and the influence of integrated segment error and Angle measurement error on deformation measurement error.Then,based on the above error analysis method,the relative precision control principle and the absolute precision control principle are proposed.Finally,the determination process of measuring point layout scheme for deep horizontal displacement measured by fixed dip sensor is given,and the determination method of measuring point layout scheme is introduced in detail through two engineering examples of unsupported foundation pit and supported foundation pit.(4)Introduce the engineering practice of the application of the fixed dip sensor in the deep horizontal displacement measurement of the foundation pit supporting structure.Firstly,the connection,installation method and acquisition system of fixed inclination sensor are introduced.Then,the fixed inclination sensor measurement point layout method and sensor connection,installation and acquisition scheme are applied to two engineering examples,and the fixed inclination sensor layout scheme,site installation,data acquisition and data analysis process are introduced in detail.Finally,through the comparison and analysis of the measurement results of the fixed dip sensor and the traditional portable manual measurement method,the feasibility and accuracy of the application of the fixed dip sensor measurement method in the deep horizontal displacement measurement are illustrated.This paper proposes a deep horizontal displacement measurement method based on a fixed dip Angle sensor,which provides theoretical guidance for the sensor layout scheme of deep horizontal displacement measurement.The method of connection and installation of the fixed inclinometer proposed in this paper solves the complex problem of installation of the fixed inclinometer to some extent.The above research results have been verified in two foundation pit engineering projects and have certain engineering value.