SBIR Phase I: A Non-Destructive Method for Examining BridgeFoundations

这个小企业创新研究第一阶段项目将开发和完善非破坏性方法，通过非破坏性和非侵入性地震测量手段，可以确定桩和钻孔井的长度和数量以及桥梁基础中存在严重结构缺陷。提出了横波反射剖面法（SWRS）和环境振动测量法（AVS）。第二个目标将是通过实地实验确定这些方法可能具有的任何限制。一个已知的限制是，目前可用的常规方法都不能确定桩宽。经过偏移数据处理步骤，可以从SWRS数据中确定桩宽或井径以及桩群中的桩数。测桩数/组、井距和桩宽/直径是数据可获得水平分辨率的函数，而水平分辨率由探测器间距和源峰频率等现场数据采集参数控制。具体来说，将在德克萨斯州交通部（TxDOT）休斯顿区休斯顿大学附近I-45沿线的桥梁基础上进行横波地震反射剖面调查和环境振动调查，以桥梁上的交通作为激励力，作为验证两种方法有效性和实用性的手段。德州交通部休斯顿区表示，他们将协助该项目进入测试场地并获取竣工施工记录。美国联邦公路管理局估计，在未来20年里，必须投资1649亿美元来解决巨大的修复积压和改善日益增加的桥梁缺陷。拟议研究的好处是，通过确定哪些桥梁基础是安全的，哪些需要修复，可以大大节省桥梁基础修复的成本。这种节省大量成本的潜力将使调查系统的商业可用性对系统供应商和最终用户都是有利可图的。

This Small Business Innovation Research Phase I project will develop and refine non-destructive methods by which the lengths and numbers of piles and drilled shafts and the existence of severe structural defects in bridge foundations can be determined through non-destructive and non-invasive seismic survey means. The survey techniques proposed are the shear wave reflection profiling survey (SWRS) method and the ambient vibration survey (AVS) method. A secondary objective will be to determine through field experimentation any limitations that the methods may have. A known limitation is that none of the currently available conventional methods can determine pile widths. After the migration data processing step, it is possible to determine the pile width or shaft diameter and the number of piles in a pile group from the SWRS data Measuring pile numbers/group, shaft separation and width/diameter is a function of the horizontal resolution obtainable from the data, which is controlled by the field data acquisition parameters of detector spacing and source peak frequency. Specifically, shear-wave seismic reflection profiling surveys and ambient vibration surveys will be conducted, using traffic on the bridge as the exciting force, of bridge foundations along I-45 near the University of Houston in the Houston District of the Texas Department of Transportation (TxDOT) as a means of verifying the validity and utility of both methods. The Houston District of TxDOT has indicated that they will assist the project in gaining access to the test sites and to the as-built construction records. The Federal Highway Administration estimates that over the next 20 years $164.9 billion must be invested to address the tremendous rehabilitation backlog and improve accruing bridge deficiencies. The benefits of the proposed research would be very significant cost savings in the rehabilitation of bridge foundations by identifying which bridge foundations are safe and which need rehabilitation. The potential for such significant cost savings will make the commercial availability of a survey system a profitable undertaking for both the system supplier and the end user.