Liquefaction-induced lateral spread displacements cause severe damage to infrastructure, resulting in large economic losses in affected regions. Predicting lateral spread displacements is an important aspect in any seismic analysis and design, and many different methods have been developed to accurately estimate these displacements. However, the inherent uncertainty in predicting seismic events, including the extent of liquefaction and its effects, makes it difficult to accurately estimate lateral spread displacements. Current conventional methods of predicting lateral spread displacements do not completely account for uncertainty, unlike a performance-based earthquake engineering (PBEE) approach that accounts for the all inherent uncertainty in seismic design. The PBEE approach incorporates complex probability theory throughout all aspects of estimating liquefaction-induced lateral spread displacements. A new fully-probabilistic PBEE method, based on results from the cone penetration test (CPT), was created for estimating lateral spread displacements using two different liquefaction triggering procedures. To accommodate the complexity of all probabilistic calculations, a new seismic hazard analysis tool, CPTLiquefY, was developed. Calculated lateral spread displacements using the new fully-probabilistic method were compared to estimated displacements using conventional methods. These comparisons were performed across 20 different CPT profiles and 10 cities of varying seismicity. The results of this comparison show that the conventional procedures of estimating lateral spread displacements are sufficient for areas of low seismicity and for lower return periods. However, by not accounting for all uncertainties, the conventional methods under-predict lateral spread displacements in areas of higher seismicity. This is cause for concern as it indicates that engineers in industry using the conventional methods are likely under-designing structures to resist lateral spread displacements for larger seismic events.

Liquefaction-induced lateral spread displacements cause severe damage to infrastructure, resulting in large economic losses in affected regions. Predicting lateral spread displacements is an important aspect in any seismic analysis and design, and many different methods have been developed to accurately estimate these displacements. However, the inherent uncertainty in predicting seismic events, including the extent of liquefaction and its effects, makes it difficult to accurately estimate lateral spread displacements. Current conventional methods of predicting lateral spread displacements do not completely account for uncertainty, unlike a performance-based earthquake engineering (PBEE) approach that accounts for the all inherent uncertainty in seismic design. The PBEE approach incorporates complex probability theory throughout all aspects of estimating liquefaction-induced lateral spread displacements. A new fully-probabilistic PBEE method, based on results from the cone penetration test (CPT), was created for estimating lateral spread displacements using two different liquefaction triggering procedures. To accommodate the complexity of all probabilistic calculations, a new seismic hazard analysis tool, CPTLiquefY, was developed. Calculated lateral spread displacements using the new fully-probabilistic method were compared to estimated displacements using conventional methods. These comparisons were performed across 20 different CPT profiles and 10 cities of varying seismicity. The results of this comparison show that the conventional procedures of estimating lateral spread displacements are sufficient for areas of low seismicity and for lower return periods. However, by not accounting for all uncertainties, the conventional methods under-predict lateral spread displacements in areas of higher seismicity. This is cause for concern as it indicates that engineers in industry using the conventional methods are likely under-designing structures to resist lateral spread displacements for larger seismic events.

Cone penetration in sands is a complex process: it contains several challenges that geomechanicians face, such as large displacements, large strains, strain localization, and microscale phenomena such as particle crushing and sand fabric evolution. In order to gain a deeper understanding of the penetration process and the mechanisms controlling penetration resistance, capturing these displacement and strain fields and microscale phenomena is necessary. Furthermore, as more sophisticated theoretical models become available for the simulation of the cone penetration problem, the experimental validation of those methods becomes vital.<br><div><br></div><div>This dissertation presents a multiscale study of the cone penetration process in silica sands. The penetration problem is investigated using a combinational approach consisting of calibration chamber experiments, digital image correlation (DIC) analysis, and X-ray computed Tomography (XCT) scans. Three silica sands with different particle characteristics are used in the experimental program. These three sands have similar particle size distributions; however, they differ in particle morphologies and particle strengths. These differences allow a study of the effect of microscale sand properties on the macroscale response of the sands to the cone penetration process. The three silica sands used in this research are fully characterized using laboratory experiments to obtain particle size distributions, particle morphologies, particle crushing strengths, minimum and maximum packing densities, and critical-state friction angles. Subsequently, both dense and medium-dense samples of the three sands are compressed in a uniaxial loading device placed inside an X-ray microscope (XRM) and scanned at multiple stress levels during uniaxial compression. Results from uniaxial compression experiments indicate that: (1) the compressibility of the sands is closely tied to particle morphology and strength, and (2) the anisotropy in the orientations of interparticle contact normals generally increases with axial stress; however, this increase is limited by the occurrence of particle crushing in the sample.<br></div><div><br></div><div>Subsequently, cone penetration experiments are performed under different confinement levels on dense samples of the three sands in aspecial half-cylindrical calibration chamber equipped with DIC capabilities. For each penetration experiment, incremental displacement fields around the cone penetrometer are obtained using DIC analysis, and these incremental displacement fields are further analyzed to compute the incremental strain fields. A novel methodology is developed to obtain the shear-band patterns that develop around the penetrometer automatically. Furthermore, differences in the shear-band patterns in deep and shallow penetration environments are also investigated. Results show that strain fields tend to localize intensely near the penetrometer tip, and the shear bands tend to develop along the inclined face and near the shoulder of the penetrometer. Significant differences in the shear band patterns in deep and shallow penetration environments are also observed.<br></div><div><br></div><div>After each cone penetration experiment, a specially developed agar-impregnation technique is used to collect minimally disturbedsand samples from around the penetrometertip. These agar-impregnated sand samples are scanned in the XRM to obtain 3D tomography data, which are further analyzed to quantify particle crushing around the penetrometer tip. The results show that: (1) for a given sample density, the amount of crushing around the cone penetrometer depends on the confinement and the sand particle characteristics, (2) the level of crushing is not uniform around the penetrometer tip, with more severe crushing observed near the shoulder of the penetrometer, and (3) the regions with more severe particle crushing around the penetrometer approximately overlap with regions of high shear strain and volumetric contraction. A framework is also proposed to obtain the ratio of penetration resistance in more crushable sands to penetration resistance in less crushable sands. Furthermore, a novel resin-impregnation technique is also developed to collect undisturbedsand samples from around the penetrometer tip. The resin-impregnated sand sample collected after one of the penetration experiments is scanned in the XRM to obtain the 3D tomography data, which is then analyzed to obtain the distribution of interparticle contact normal orientations at multiple locations around the penetrometer tip. These analyses indicate that the interparticle contact normals tend to orient themselves with the incremental principal strains around the penetrometer: below the penetrometer tip, the interparticle contact normals orient vertically upwards, while closer to the shoulder of the penetrometer, the interparticle contact normals become more radially inclined.<br></div><div><br></div><div>Data presented in this dissertation on penetration resistance, incremental displacement fields, incremental strain fields, particle crushing, and interparticle contact normal orientations around the cone penetrometer are aimed to be useful to researchers working on the multiscale modeling of penetration processes in granular materials and aid in the further development of our understanding of penetration processes in sands.<br></div>

京都大学 / 新制・課程博士 / 博士(工学) / 甲第25251号 / 工博第5210号 / 新制||工||1994(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 安原 英明, 准教授 橋本 涼太, 准教授 澤村 康生 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

The object of the thesis is soils that occur within the territory of Lithuania and may be used as basis for building foundations. The thesis studies the interpretation of the results of Dynamic Penetration Test (DPT) and Cone Penetration Test (CPT) of soils, reliability of direct (number of blows (Nx)) and de-rivative (dynamic point resistance (qd)) DPT parameters, analyses the result influencing factors and interrelation between DPT and CPT parameters. The data analysis has been performed by means of mathematical methods of statistics, also using analytical and empirical solutions. Having examined calculation data it was determined that the indirect parameter of Dy-namic Penetration Test – dynamic point resistance (qd) should not be used due to calculation de-faults and replaced with the direct parameter – number of blows (Nx). The analysis of DPT re-sults influencing factors shows that the lateral overburden pressure together with friction of rods are those with the greatest impact on penetration data. Within the scope of the work, it has re-vealed that the number of blows (Nx) and static cone resistance (qc) are closely correlated and it depends on the grain size distribution of soil, geotechnical properties and depth of occurrence. / Disertacijos objektas yra Lietuvos teritorijoje slūgsantys gruntai, kurie gali būti statinių pamatų pagrindu. Disertacijoje nagrinėjama grunto tyrimo dinaminiu (DPT) ir statiniu (CPT) zondavimu rezultatų interpretacija, tiesioginio (smūgių skaičiaus (Nx)) ir išvestinio (dinaminės kūgio smigos (qd)) DPT rodiklių patikimumas, analizuojami rezultatus įtakojantys veiksniai ir sąsajos tarp DPT bei CPT zondavimo rodiklių. Duomenų analizė atlikta matematiniais statistiniais metodais, taip pat panaudojant analitinius ir empirinius sprendinius. Išnagrinėjus skaičiavimo duomenis buvo nustatyta, kad netiesioginis dinaminio zonda-vimo rodiklis – dinaminė kūgio smiga (qd) dėl skaičiavimo trukumų yra nenaudotinas ir keisti-nas į tiesioginį rodiklį – smūgių skaičių (Nx). DPT rezultatus įtakojančių veiksnių analizė paro-dė, kad zondavimo duomenims didžiausią įtaką turi gruntų šoninis geostatinis slėgis ir kartu zondavimo štangų trintis į gruntą. Darbo metu buvo gauta, kad egzistuoja tamprus koreliacinis ryšys tarp smūgių skaičiaus (Nx) ir statinės kūgio spraudos (qc), kuris priklauso nuo grunto gra-nuliometrinės sudėties, mechaninių savybių ir slūgsojimo gylio.

Disertacijos objektas yra Lietuvos teritorijoje slūgsantys gruntai, kurie gali būti statinių pamatų pagrindu. Disertacijoje nagrinėjama grunto tyrimo dinaminiu (DPT) ir statiniu (CPT) zondavimu rezultatų interpretacija, tiesioginio (smūgių skaičiaus (Nx)) ir išvestinio (dinaminės kūgio smigos (qd)) DPT rodiklių patikimumas, analizuojami rezultatus įtakojantys veiksniai ir sąsajos tarp DPT bei CPT zondavimo rodiklių. Duomenų analizė atlikta matematiniais statistiniais metodais, taip pat panaudojant analitinius ir empirinius sprendinius. Išnagrinėjus skaičiavimo duomenis buvo nustatyta, kad netiesioginis dinaminio zonda-vimo rodiklis – dinaminė kūgio smiga (qd) dėl skaičiavimo trukumų yra nenaudotinas ir keisti-nas į tiesioginį rodiklį – smūgių skaičių (Nx). DPT rezultatus įtakojančių veiksnių analizė paro-dė, kad zondavimo duomenims didžiausią įtaką turi gruntų šoninis geostatinis slėgis ir kartu zondavimo štangų trintis į gruntą. Darbo metu buvo gauta, kad egzistuoja tamprus koreliacinis ryšys tarp smūgių skaičiaus (Nx) ir statinės kūgio spraudos (qc), kuris priklauso nuo grunto gra-nuliometrinės sudėties, mechaninių savybių ir slūgsojimo gylio. / The object of the thesis is soils that occur within the territory of Lithuania and may be used as basis for building foundations. The thesis studies the interpretation of the results of Dynamic Penetration Test (DPT) and Cone Penetration Test (CPT) of soils, reliability of direct (number of blows (Nx)) and de-rivative (dynamic point resistance (qd)) DPT parameters, analyses the result influencing factors and interrelation between DPT and CPT parameters. The data analysis has been performed by means of mathematical methods of statistics, also using analytical and empirical solutions. Having examined calculation data it was determined that the indirect parameter of Dy-namic Penetration Test – dynamic point resistance (qd) should not be used due to calculation de-faults and replaced with the direct parameter – number of blows (Nx). The analysis of DPT re-sults influencing factors shows that the lateral overburden pressure together with friction of rods are those with the greatest impact on penetration data. Within the scope of the work, it has re-vealed that the number of blows (Nx) and static cone resistance (qc) are closely correlated and it depends on the grain size distribution of soil, geotechnical properties and depth of occurrence.

Portrycket är en viktig parameter för att bestämma jordens egenskaper, såsom dränering, permeabilitet och stabilitet (då portrycket har en påverkan på den effektiva spänningen i jorden). Portrycket kan mätas med portrycksmätare men det kan även mätas under ett Cone penetrating test (CPT) med ett s.k. dissipationstest. Fördelar med ett dissipationstest jämfört med traditionell portrycksmätning skulle vara att det skulle spara tid och pengar, då man slipper trycka ner portrycksmätare och sedan vänta på att få portrycket ifrån dem, istället kan portrycket mätas under sondering med CPT.Detta självständiga arbete har som syfte att jämföra portrycksmätningar mellan portrycksmätning med BAT-spets och dissipationstest under CPT-sondering för att se hur bra mätvärden dissipationstester ger och om de eventuellt kan ersätta portrycksmätare. Fältförsöken av metoderna skedde i Uppsalalera, på en tomt i Kungsängen i Uppsala.Två stationer med BAT-spetsar på 5 meter, 7,5 meter och 10 meters djup sattes ner i leran. Sondering med CPT genomfördes sedan, där borren stoppades på samma djup som BAT-spetsarna. CPT:n stoppades på dessa djup i drygt 24 timmar, för att tillåta det generade portrycket som skapades när borren trycks ner i leran att skingras åt sidan. Jämviktsportrycket kommer vara det portryck som finns kvar efter att det generade portrycket har försvunnit. Portrycken från de två olika metoderna jämfördes sedan för att se hur nära dissipationstestet kommer värdena från portrycksmätningen med BAT-spetsarna.Resultatet av dissipationstesterna blev att inga av dem nådde referensvärdena från BAT-spetsarna efter 24 timmar. Beroende på användningsklass ligger dissipationstesterna inom den tillåtna minsta noggrannheten. Dissipationstest är antagligen inte så praktiskt tillämpbart i jordar med låg permeabilitet. / The pore pressure is an important parameter for determining the properties of thesoil, such as drainage, permeability and stability (since the pore pressure has aneffect on the effective stress in the soil). The pore pressure can be measured withpore pressure gauges but it can also be measured during a Cone penetration test(CPT) with a dissipation test. Advantages of a dissipation test compared tomeasurement with traditional pore pressure gauges would be that it would save timeand money, since you don’t have to press down pore pressure gauges and then waitto get the pore pressure from them, instead the pore pressure can be measuredduring probing with CPT.The purpose of this project is to compare pore pressure measurements betweenpore pressure measurements with BAT-tips and dissipation test during CPT probing,to see how good measured values the dissipation tests will provide and if theyeventually can supersede pore pressure gauges for pore pressure measurements.The field tests of the methods were done in Uppsala clay, on a site in Kungsängen inUppsala.Two stations with BAT-tips at 5 meters, 7.5 meters and 10 meters depth wereinstalled in the clay. Probing with CPT was then carried out, by stopping the CPT atthe same depth as the BAT-tips. Measurements with the CPT were done at thesedepths for just over 24 hours, to allow the generated excess pore pressure createdwhen the cone is pushed into the clay to disperse to the sides. The equilibrium porepressure is the pore pressure that remains after the generated pore pressure hasdissipated. The pore pressure from the two different methods was then compared tosee how close the dissipation test results were to the values from the pore pressuremeasurements with the BAT tips.The result of the dissipation tests was that none of them reached the referencevalues from the BAT-tips after 24 hours. Depending on the chosen application class,the dissipation tests are within the permitted minimum accuracy. Dissipation tests areprobably not practically applicable to soils with low permeability.

Evaluations of stress history and the geostatic state of stress of soils are ascertained on the basis of field geophysical measurements that provide paired complementary types of shear waves. It is well-established that multiple types of shear waves occur in the ground due to their directional and polarization properties. The shear wave velocity (Vs) provides the magnitude of small strain stiffness (G0) which depends on effective stress, void ratio, stress history, and other factors (cementation, age, saturation). Herein, this study examines a hierarchy of shear wave modes with different directions of propagation and particle motion from in-situ geophysical tests (HH, VH, and HV) and laboratory bender element data. A special compiled database from well-documented worldwide sites is assembled where full profiles of stress state, stress history, and several paired modes of Vs profiles have been obtained from crosshole tests (CHT), downhole tests (DHT), and rotary crosshole (RCHT). Reference profiles of the lateral stress coefficient (K0) are available from direct in-situ measurements (self-boring pressuremeter, hydrofracture, and push-in spade cells). Stress history is documented in terms of yield stress ratio (YSR) from consolidation testing and careful engineering geology studies. A methodology is developed that relates both the YSR and K0 to stiffness ratios obtained from directional shear wave velocities. In further efforts, means to extract reliable shear wave profiles from continuous downhole testing via a new GT autosource and seismic piezocone testing are outlined and applied to results from three test sites in Windsor/VA, Norfolk/VA, and Richmond/BC. A driving impetus to this research involves the geologic conditions at the US Dept. of Energy's Savannah River Site (SRS) in South Carolina. Here, the overburden soils in the upper 60 m depths consist of very old Miocene and Eocene sediments, primarily layered deposits of sands, clayey sands, silty sands, and interbedded clays which exhibit an apparent and unusual stress history profile. Special geologic conditions include the dissolutioning of old calcareous sediments (Santee Formation) at depths of 40 to 50 m below grade, similar to karstic limestone deposits. As a consequence, caves, voids, and infilled soft soil zones occur within the soil matrix at these elevations, probably resulting in localized collapse of the overlying soil column. Based on conventional laboratory and in-situ test data conducted during geotechnical investigations at SRS, available interpretative relationships for assessing the soil stress history and geostatic stress states show scattered and inconsistent results. Complications abound in the systematic assessments of these geomaterials due to effects of very old ageing, cementation, desiccation, and diagenesis, as evidenced by unusual in-situ shear wave velocity profiles that decrease in magnitude with depth, as measured by CHT and DHT. Based on the findings of this study, it is recommended that a new set of shear wave velocity measurements be made at SRS to obtain HH waves (and complementary VH waves) needed for an independent assessment of YSR in the upper soil column.

Baigiamajame magistriniame darbe susietas Lietuvos moreninių molinių gruntų pavadinimas (pagal LST EN ISO 14688-2:2006) su statinio zondavimo (CPTu) duomenimis. Darbą sudaro teorinė ir praktinė dalys. Teorinėje dalyje aptartos sudarytos gruntų klasifikacijos pagal CPT ir CPTu duomenis, aprašytos tyrime naudojamų gruntų vietovės inžinerinės-geologinės sąlygos bei sudaryta tyrimo metodologija, kurioje pateiktos formulės CPT ir CPTu rodiklių santykio apskaičiavimui, aprašomas grunto pavadinimo nustatymas pagal granuliometrinę sudėtį bei taikomas metodas molinių gruntų granuliometrinės sudėties nustatymui. Trumpai aprašomi tyrime taikyti principai. Praktinėje dalyje išsamiai aprašyti ir išanalizuoti skaičiavimuose naudojami duomenys, surastos priklausomybės, sudaryta gruntų pavadinimo nustatymo schema bei įvertinta gruntų klasifikacija pagal aptartus 4 metodus. Pateiktos išvados ir siūlymai tolimesniam darbui bei gautų rezultatų patikslinimui. Darbą sudaro 8 pagrindinės dalys: įvadas, atliktų darbų apžvalga, vietovės inžierinės-geologinės sąlygos, tyrimo metodologija, tyrimo rezultatai, išvados, literatūros sąrašas ir priedai. Darbo apimtis – 50 p. teksto be priedų, 59 p. priedų, 20 literatūros šaltiniai, 30 pav. ir 5 lentelės. / The present Master Thesis forms a link between the names of the Lithuanian moraine argillaceous soils (according to LST EN ISO 14688-2:2006) and the data of the cone penetration test (CPTu). The paper consists of a theoretical part and a research. The theoretical part is devoted to discussing formulated soil classifications according to the data of CPT and CPTu, describing the engineering/ geological conditions of the soil locations investigated in the research and presenting the research methods. The research methods include the formulas for calculating the CPT and CPTu indicator ratio, description of determining the soil name according to the particle size distribution and application of the method for determining the particle size distribution of argillaceous soils. The principles employed in the research are also briefly described. The research includes a detailed description and analysis of the data used in the calculations and the discovered dependencies, the formulated soil name determination plan and the soil classification assessed according to the discussed four methods. At the end of the paper, conclusions and recommendations are given for further work and specification of the received results. The study consists of the following eight parts: introduction, review of the earlier studies, engineering/ geological conditions of the location, research methods, research results, conclusions, references and annexes. The paper consists of 50 pages without annexes, 59 pages... [to full text]

One of the most critical problems geotechnical engineers face with is the determination of the amount of consolidation settlement that will occur at a site as a result of the construction of a structure. The compressibility behavior of the soil is an important parameter in determining the amount of consolidation settlement. The goal of this study is to develop probabilistically based correlation between the compressibility behavior of soil and in-situ test data. Within the scope of this research effort, performed CPT tests and the recorded settlement case histories where consolidation settlements at the field under various surcharge loads were compiled from the Bursa East and West Waste Water Treatment Plant soil investigation projects. A database was composed of the results of 45 CPT and 57 settlement plate recordings. For the compilation of this database, a series of finite difference software FLAC-3D analyses were carried out to calculate the change in stress distribution under the settlement plates. A maximum likelihood framework was used for the development of compressibility behavior of soils. As a result of careful processing of available data, the cone tip resistance (qc), soil behavior type index (Ic) were selected as two important parameters effecting the value of the one-dimensional constraint modulus, M. The regression analysis which uses the settlement values recorded at the site and those computed using the change in the stress distribution, the thickness of the sublayers and the proposed one-dimensional constraint modulus were carried out to calculate the values of these model parameters. Two correlations based on the cone tip resistance and soil behavior type index were developed for the computation of the one-dimensional constraint modulus, M.