软土地基真空预压现场试验研究与监测分析

发布时间：2018-04-15 23:16

本文选题：软土地基 + 真空预压　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：近些年来,国家为了提高海洋资源开发利用,提高国民经济水平,越来越多的资本涌入了海洋建设和开发的浪潮中,我国沿海地区开始陆陆续续的建设各类港口、码头等建构筑物。但是这类地区广泛分布着海相沉积的软土层,软土地基具有大沉降量、低承载力以及固结时间漫长等工程特性,在其上建造的各种构筑物会在使用阶段产生不均匀沉降及变形,影响到构筑物的正常使用,严重者甚至造成安全事故。因此,天然软土地基往往难以满足大型工程对稳定性和地基变形的要求,所以必须对其进行地基加固处理。目前工程中常用的深厚软土地基处理的主要有真空预压法、堆载预压法、真空联合堆载预压法等,其排水体材料普遍使用塑料排水板。直排式真空预压法是在真空预压法的基础上衍生而来的,该法具有方法简便、操作简易、成效明显和成本较低等优点,能在处理软基中获得理想的加固效果。本文将从现有研究现状和实际存在的问题入手,以大连大窑湾某沿海吹填软基真空预压的工程为依托,通过现场埋设不同的试验仪器采集可靠的试验数据,并对它们进行分析研究,可以得到真空预压对处理软基的试验结论和预压成效:(1)根据试验场地的工程水文地质资料,对大连大窑湾地区某沿海软土地基的实际工程采用真空预压加固深厚软土地基工程实践,开展了系统的预压场地加固处理的试验和研究,并分析了直排式真空预压加固软基处理方法在应用于深厚软基时,加固期间的工程性状和工程问题。(2)在真空预压处理地基期间,现场布置的监测设备采集到膜下真空度、地表沉降、孔隙水压力等多项数据的变化情况,并研究和分析其变化的规律性。(3)应用Plaxis有限元模拟程序,基于现场试验数据,对其进行建模计算,并且对模拟结果展开分析研究,以模拟现场和还原现场的预压情况,对模拟数据和现场试验结果进行比对以检验模拟的可靠性和实用性。(4)在完成以上各项模拟工作的基础上,对试验场地展开工后各项数据的模拟预测工作,预测后期沉降及其他数据的变化情况,为指导大窑湾后期建设提供可靠数据。并且进一步丰富当地软土地基加固的现场试验和施工经验。
[Abstract]:In recent years, in order to improve the exploitation and utilization of marine resources and raise the level of national economy, more and more capital has poured into the tide of ocean construction and development, and the coastal areas of our country have started to build various kinds of ports one after another.A quay, etc.However, the soft soil layer is widely distributed in this area. The soft soil foundation has the engineering characteristics of large settlement, low bearing capacity and long consolidation time, and the structures built on it will produce uneven settlement and deformation in the service stage.Affect the normal use of the structure, serious or even cause safety accidents.Therefore, natural soft soil foundation is difficult to meet the requirements of stability and foundation deformation in large engineering, so it is necessary to strengthen the foundation.At present, the treatment of deep soft foundation in engineering mainly includes vacuum preloading method, surcharge preloading method, vacuum combined surcharge preloading method and so on. Plastic drainage board is widely used in the drainage body material.The direct row vacuum preloading method is derived from the vacuum preloading method, which has the advantages of simple method, simple operation, obvious effect and low cost, and can obtain ideal reinforcement effect in the treatment of soft foundation.In this paper, based on the existing research situation and practical problems, based on the vacuum preloading project of a coastal filling soft foundation in Dalian Dayaowan, the reliable test data are collected through different test instruments on the spot.By analyzing and studying them, we can get the test conclusion of vacuum preloading for soft foundation treatment and the preloading effect: 1) according to the engineering hydrogeological data of the test site,In this paper, the practice of strengthening deep soft foundation by vacuum preloading in a coastal soft foundation project in Dayaowan area of Dalian is carried out, and the test and research on the consolidation treatment of preloading site are carried out systematically.This paper also analyzes the engineering behavior and engineering problem during the consolidation of deep soft foundation by the straight-row vacuum preloading method. During the vacuum preloading treatment, the vacuum degree under the film is collected by the monitoring equipment arranged in the field.The variation of surface subsidence, pore water pressure and so on, and the regularity of its variation are studied and analyzed. The finite element simulation program of Plaxis is used to model and calculate the surface subsidence and pore water pressure based on the field test data.And the simulation results are analyzed and studied to simulate the preloading situation of the field and the reduction field, and to compare the simulation data with the field test results to verify the reliability and practicability of the simulation. (4) on the basis of the above simulation work,In order to provide reliable data for the later construction of Dayaowan Bay, the simulation and prediction of the post-construction data of the test site and the prediction of the later settlement and other data changes are carried out in order to provide reliable data for guiding the later construction of Dayao Bay.And further enrich the local soft soil foundation consolidation site test and construction experience.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U655.544.4

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