Research On Buoyancy Calculation And Anti-floating Measures Of Slope Building Underground Structure

In recent years,promoting urbanization processes has greatly enhanced China’s overall national strength.However,the lack of urban development space in major cities have caused a series of disadvantages including insufficient living space,traffic congestion,and insufficient green space in cities.In order to increase city capacity,improve residential quality of life,and reduce traffic congestion,construction companies are looking towards designing multi-level urban spatial structures(i.e.high-rise and underground buildings).At the same time,in order to solve the contradiction between the shortage of land in first-tier and second-tier cities,building construction has begun in undeveloped slopes of mountainous regions.However,compared with the conventional flat ground structure,the terrain of the hillside varies greatly.The groundwater level varies upon seasonal precipitation which can cause the water level to float.The anti-floating water level provided by the survey data may be far from the actual water level.However,structural design engineers who fail to understand the role of ground water in engineering design are more likely to cause future anti-floating failure accidents of engineering structures.This article firstly summarizes the relevant research results of anti-floating waterproof level at home and abroad,introduces the current national regulations,and further points out that current regulations lack clear provisions for anti-floating water levels of underground structures on slopes.At the same time,various anti-floating measures commonly used in engineering are introduced,and the research results on anti-floating anchors are conveyed.Secondly,the existence form of groundwater,the seepage characteristics of groundwater and the basic laws are analyzed,and several existing buoyancy analysis theories of underground structures on slopes are described.The modified principle of the modified resistance coefficient method is used to calculate the underground structure water of a project in Heshan.The theoretical water buoyancy was calculated,and the actual water buoyancy of the basement floor of the sloping ground under different conditions was measured using finite element software.The analysis results were compared with the calculation results of the improved resistance coefficient method,and the anti-floating water level of the basement structure floor of the project was comprehensively determined in combination with engineering experience.Thirdly,based on the actual case of the project,root cause analysis is conducted regarding the anti-floating failure of the basement floor of the project,and the engineering accident is pointed out as a local anti-floating failure accident.At the same time,the different anti-floating reinforcement schemes are compared and analyzed.From an economy and applicably perspective,the final anti-floating reinforcement design scheme is a composite reinforcement scheme that thickens the basement structure floor,sets anti-floating anchors,and drains and releases pressure.The reinforcement project was inspected during a rainy season,and the surface of the newly poured concrete slab in the basement did not show water seepage damage,indicating that the treatment scheme determined according to the research results of this paper is feasible.Finally,combined with the project’s analysis of the characteristics of the underground structure of the sloping building,it is pointed out that the anti-floating anchor is a superior anti-floating measure when the anti-floating design of the sloping building structure is designed.The structure,classification and working mechanism of anti-floating anchors were introduced in detail.Based on research of the working mechanism of anti-floating anchors,the factors affecting the bearing capacity of anti-floating anchors and the calculation methods of bearing capacity are discussed.At the same time,the finite element software is used to simulate the single variable for different influencing factors of anti-floating anchors,determine the force characteristics of anti-floating anchors under various influencing factors,and verify them through field tests.Finally,the engineering recommendations are provided.The research results of this paper have guiding significance for engineering application of anti-floating design and anti-floating accident treatment of underground structures of sloping buildings.