scholarly journals Model Tests and FE-Modelling of Dynamic Soil-Structure Interaction

2012 ◽  
Vol 19 (5) ◽  
pp. 1061-1069
Author(s):  
N. Kodama ◽  
K. Komiya
Keyword(s):  
Soil Structure ◽  
Inertial Force ◽  
Earth Pressure ◽  
Elastic Model ◽  
Clear Understanding ◽  
Interface Model ◽  
Force Transmission ◽  
Fe Modelling ◽  
Seismic Force ◽  
Study Laboratory

The forces applied to a structure from the soil ground during an earthquake and the dynamic response of a structure are problems that are not well understood. In recent years, seismic design technology aided by numerical simulation is under active development. Successful improvement of the accuracy and reliability of numerically simulated results relies on a clear understanding of the seismic force transmission mechanism between the soil and a structure associated with mechanical properties of soil.In this study, laboratory shaking tests were conducted using the unique apparatus designed to have a structure move only by its inertial force and the lateral earth pressure that comes from surrounding sandy soils. The earth pressure at the structure surface and the relative displacement between the soil and the structure were measured in the experiments under various conditions. A new Finite Element interface model for sandy soil-structure dynamic interaction is proposed from the experimental results. Estimated seismic responses of a bridge pier calculated by the proposed interface model, conventional linear elastic model and tension cut-off model are compared.

scholarly journals Experimental behaviour of concrete box culverts — comparison with current codes of practice

2019 ◽  
Vol 56 (7) ◽  
pp. 970-982 ◽  
Author(s):  
Nuno Cristelo ◽  
Carlos Félix ◽  
Joaquim Figueiras
Keyword(s):  
Numerical Models ◽  
Earth Pressure ◽  
Element Model ◽  
Structural Deformation ◽  
Elastic Model ◽  
Optimized Design ◽  
Underground Structures ◽  
State Highway ◽  
Codes Of Practice ◽  
Earth Pressures

It is now accepted that current expeditious models for determining earth pressures on flexible underground structures under compacted layers do not include several technical nuances of the soil–structure interaction. Thus, these models are not capable of delivering an optimized design. The present paper compares the results from the well-known American Association of State Highway and Transportation Officials (AASHTO) model with two different numerical models — a user-friendly elastic model and a more robust finite element model — and with results retrieved from a full-scale monitoring of a concrete box culvert, 5.5 m high and 3.77 m width, over which a 15 m high embankment was built. This structure was instrumented selectively, over a period of almost 1 year, during which several parameters were recorded, including earth pressures and structural deformation. Results have shown that the two most significant drawbacks associated with the use of the AASHTO model are the inadequate evaluation of vertical pressure on the top slab and the coefficient of earth pressure, which results in a significant overestimation of the lateral pressures and, consequently, in an overall inefficient design of the structure.

Full-scale shake table investigation of bridge abutment lateral earth pressure

2009 ◽  
Vol 42 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Patrick Wilson ◽  
Ahmed Elgamal
Keyword(s):  
Large Scale ◽  
Dynamic Pressure ◽  
Inertial Force ◽  
Earth Pressure ◽  
Shake Table ◽  
Passive Force ◽  
Dense Sand ◽  
Lateral Earth Pressure ◽  
Bridge Abutment ◽  
Force Displacement

During strong seismic excitation, passive earth pressure at the abutments may provide resistance to longitudinal displacement of the bridge deck. The dynamic pressure component may also contribute to undesirable abutment movement or damage. Current uncertainty in the passive force-displacement relationship and in the dynamic response of abutment backfills continues to motivate large-scale experimentation. In this regard, a test series is conducted to measure static and dynamic lateral earth pressure on a 1.7 meter high bridge abutment wall. Built in a large soil container, the wall is displaced horizontally into the dense sand backfill, in order to record the passive force-displacement relationship. The wall-backfill system is also subjected to shake table excitation. In the conducted tests, lateral earth pressure on the wall remained close to the static value during the low to moderate shaking events (up to about 0.5g). At higher levels of input acceleration, a substantial portion of the backfill inertial force started to clearly act on the wall.

Calculating Method of Active Earth Pressure behind Rigid Retaining Wall Based on Pseudo-Dynamic Theory

2011 ◽  
Vol 368-373 ◽  
pp. 2932-2938
Author(s):  
Kui Hua Wang ◽  
Deng Hui Wu ◽  
Shao Jun Ma ◽  
Wen Bing Wu
Keyword(s):  
Numerical Analysis ◽  
Dynamic Theory ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Active Earth Pressure ◽  
Active Force ◽  
Calculating Method ◽  
Seismic Active Earth Pressure ◽  
Action Point ◽  
Seismic Force

By means of pseudo-dynamic theory, a new calculating method is presented to calculate the pseudo-dynamic seismic active earth pressure behind rigid retaining wall. Considering time and phase difference within the backfills, the horizontal slices is used to analyze the distribution of seismic active force behind retaining wall in more realistic manner. Under the assumption that the soil backfills are rigid body, the equations derived in this paper can be degenerated to Mononobe-Okabe equations. Through numerical analysis, it is shown that the values of seismic active force obtained from present study are smaller than those obtained from Mononobe-Okabe theory and the distribution of seismic force along the depth of the wall is nonlinear. It is also found that the action point of the total seismic active earth pressure is higher than one third of the wall height, which is corresponding to previous experimental results.

scholarly journals Seismic force redistribution in asymmetrical reinforced concrete buildings due to soil-structure interaction

2020 ◽  
Author(s):  
Παρασκευή Ασκούνη
Keyword(s):  
Reinforced Concrete ◽  
Soil Structure ◽  
Soil Structure Interaction ◽  
Reinforced Concrete Buildings ◽  
Structure Interaction ◽  
Concrete Buildings ◽  
Seismic Force

Η παρούσα διατριβή διερευνά την ανακατανομή των εσωτερικών δυνάμεων μεταξύ των κατακόρυφων μελών οπλισμένου σκυροδέματος (Ο/Σ) απλών ασύμμετρων χαμηλών κατασκευών υπό σεισμική φόρτιση λαμβάνοντας υπόψη την δυναμική αλληλεπίδραση εδάφους-κατασκευής (ΔΑΕΚ). Μια σειρά μονώροφων επιπέδων πλαισίων Ο/Σ με ένα, δύο και τέσσερα ανοίγματα, εδραζόμενα επί απαραμόρφωτου ή παραμορφώσιμου εδάφους μέσω θεμελίων με συνδετήριες δοκούς αναλύεται δυναμικά. Η σεισμική φόρτιση προσομοιώνεται με συνθετικά επιταχυνσιογραφήματα συμβατά με το φάσμα σχεδιασμού του Ευρωκώδικα 8. Μονώροφα και τριώροφα 3-Δ κτιρίων Ο/Σ ενός ανοίγματος εδραζόμενα επί απαραμόρφωτου ή παραμορφώσιμου εδάφους μέσω θεμελίων με συνδετήριες δοκούς και γενικής κοιτόστρωσης, αναλύονται δυναμικά χρησιμοποιώντας πραγματικά επιταχυνσιογραφήματα.Η ασυμμετρία στα εξεταζόμενα 2-Δ και 3-Δ κτίρια Ο/Σ επιτυγχάνεται αντικαθιστώντας έναν στύλο από ένα τοίχωμα μεταβλητού πλάτους. Η συμπεριφορά των μελών Ο/Σ θεωρείται ελαστική σύμφωνα με τους ισχύοντες κανονισμούς σχεδιασμού, καθώς και ελαστοπλαστική σύμφωνα με ένα ελαστοπλαστικό μηχανικό μοντέλο ινών. Τόσο οι γραμμικές όσο και οι μη γραμμικές ελαστοπλαστικές αναλύσεις πραγματοποιούνται στο χρονικό πεδίο. Οι γραμμικές αναλύσεις γίνονται λαμβάνοντας υπόψη τη μειωμένη δυσκαμψία των μελών λόγω της ρηγμάτωσης του σκυροδέματος. Οι μη γραμμικές ελαστοπλαστικές αναλύσεις γίνονται με ένα μοντέλο συγκεντρωμένης μέσω μείωση της δυσκαμψίας. Οι μη γραμμικές ποσότητες απόκρισης περιλαμβάνουν όχι μόνο τις δυνάμεις ροπής και διάτμησης των μελών, αλλά και τις γωνιακές παραμορφώσεις ορόφων και διάφορους δείκτες βλάβης σε επίπεδα μέλους και κατασκευής για τέσσερα επίπεδα επιτελεστικότητας. Αδιάστατοι λόγοι των εσωτερικών απόλυτων μέγιστων δυνάμεων και ροπών των κατακόρυφων μελών Ο/Σ εκφράζονται ως προς τις ιδιότητες διατομής τους και συγκρίνονται για τις περιπτώσεις ΔΑΕΚ και απαραμόρφωτου εδάφους τόσο για τις ελαστικές όσο και για τις ελαστοπλαστικές αναλύσεις. Έτσι, προσδιορίζεται και συζητείται η επίδραση της ΔΑΕΚ στη σεισμική απόκριση των κατακόρυφων στοιχείων και ολόκληρης της κατασκευής. Όλες οι αναλύσεις αποδεικνύουν ότι η ΔΑΕΚ επηρεάζει έντονα τη σεισμική απόκριση μελών Ο/Σ και απλών κατασκευών Ο/Σ και η επιρροή της μπορεί να είναι ευεργετική ή επιζήμια σε αντίθεση με τους ισχύοντες κανονισμούς οι οποίοι θεωρούν μόνο τα θετικά αποτελέσματά της.

scholarly journals Stress Distribution in a Cohesionless Backfill Poured in a Silo

2014 ◽  
Vol 8 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Li Li ◽  
Jonathan D. Aubertin ◽  
Jean-Sébastien Dubé
Keyword(s):  
Soil Structure ◽  
Earth Pressure ◽  
Horizontal Stress ◽  
Density Variation ◽  
Direction Parallel ◽  
Rest State ◽  
Drop Mass ◽  
Drop Tests ◽  
Series Of Experiments ◽  
Infrastructure Rehabilitation

The field of infrastructure rehabilitation and development requires a better understanding of soil-structure interactions. The interaction behaviour between soil and structures has mostly been investigated through theoretical and/or numerical analysis. This paper presents a series of experiments performed on an intermediate-scale physical model made of an instrumented silo. In contrast to most reported laboratory tests, both the horizontal and vertical stresses were monitored during backfilling operations realised by wild pouring. Drop tests were performed to investigate the density variation with respect to the drop (or falling) height of the soil, which were introduced in the pressure interpretation. The results showed that horizontal stress in the direction parallel to the pouring plane is larger than that perpendicular to the pouring plane. Apparently, the vertical stress is well-described using the arching solution by considering the backfill in an active state, whereas the horizontal stress perpendicular to the pouring plane is better described with the arching solution by considering the backfill in an at-rest state. An estimate of the earth pressure coefficients based on the measured vertical and horizontal stresses indicates, however, that the backfill was closer to an at-rest state in the direction perpendicular to the pouring plane, whereas in the direction parallel to the pouring plane, it was in a state between at-rest and passive. These results indicate that it is important to measure both the horizontal and vertical stresses to obtain a whole picture of the state of the backfill. The results showed also that the horizontal stresses can be larger than those calculated by the overburden solution, probably due to dynamic loading by drop mass during the filling operation and stress lock.

scholarly journals Experimental Study on the Evolution Mechanism of Landslide with Retaining Wall Locked Segment

Geofluids ◽  
2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Han-Dong Liu ◽  
Jia-Xing Chen ◽  
Zhi-Fei Guo ◽  
Dong-Dong Li ◽  
Ya-Feng Zhang
Keyword(s):  
Shear Fracture ◽  
Retaining Wall ◽  
Stress Test ◽  
Pressure Sensors ◽  
Inertial Force ◽  
Slope Instability ◽  
Evolution Mechanism ◽  
Seismic Force ◽  
Mechanism Of Landslide ◽  
External Loads

The failure of locked segment-type slopes is often affected by rainfall, earthquake, and other external loads. Rainfall scours the slope and weakens the mechanical properties of rock-soil mass. At the same time, rainfall infiltrates into cracks of slope rock mass. Under the action of in situ stress, hydraulic fracturing leads to the development and expansion of rock cracks, which increases the risk of slope instability. Under seismic force, the slope will be subjected to large horizontal inertial force, resulting in slope instability. In this paper, a self-developed loading device was used to simulate the external loads such as rainfall and earthquake, and the model tests are carried out to study the evolution mechanism of landslide with retaining wall locked segment. Three-dimensional laser scanner, microearth pressure sensors, and high-definition camera are applied for the high-precision monitoring of slope shape, deformation, and stress. Test results show that the retaining wall locked segment has an important control effect on landslide stability. The characteristics of deformation evolution and stress response of landslide with retaining wall locked segment are analyzed and studied by changing the slope shape, earth pressure, and the displacement cloud map. The evolutionary process of landslide with retaining wall locked segment is summarized. Experimental results reveal that as the landslide with retaining wall locked segment is at failure, the upper part of the landslide thrusts and slides and the retaining wall produces a locking effect; the middle part extrudes and uplifts, which is accompanied with shallow sliding; and compression-shear fracture of the locked segment leads to the landslide failure.

Supporting the Engineering Analysis of Offshore Wind Turbines Through Advanced Soil-Structure 3D Modelling

2017 ◽  
Author(s):  
Simone Corciulo ◽  
Omar Zanoli ◽  
Federico Pisanò
Keyword(s):  
Dynamic Analysis ◽  
Wind Turbines ◽  
Soil Structure ◽  
Current Trend ◽  
Offshore Wind ◽  
Fe Modelling ◽  
Offshore Wind Turbines ◽  
Geotechnical Design ◽  
Foundation Type ◽  
Increasing Load

Monopiles are at present the most widespread foundation type for offshore wind turbines (OWTs), due to their simplicity and economic convenience. The current trend towards increasingly powerful OWTs in deeper waters is challenging the existing procedures for geotechnical design, requiring accurate assessment of transient soil-monopile interaction and, specifically, of the associated modal frequencies. In this work, advanced 3D finite element (FE) modelling is applied to the dynamic analysis of soil-monopile-OWT systems under environmental service loads. Numerical results are presented to point out the interplay of soil non-linearity and cyclic hydro-mechanical (HM) coupling, and its impact on transient response of the system at increasing load magnitude. It is shown how the lesson learned from advanced modelling may directly inspire simplified, yet effective, spring models for the engineering dynamic analysis of OWTs.

scholarly journals Soil Densification Effect on The Seismic Response of Structures Taking into Consideration Soil-Structure Interaction

2021 ◽  
Vol 2 (4) ◽  
pp. 13-17
Author(s):  
Radhwane Boulkhiout
Keyword(s):  
Dynamic Response ◽  
Seismic Response ◽  
Soil Structure ◽  
Lateral Displacement ◽  
Motion Vector ◽  
Stability Index ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Seismic Force ◽  
Soil Densification

Soil compaction is a considerable construction activity to ensure safety and durability, notably in the transportation industry. This technique of compaction increases soil bulk density and soil strength, while decreases porosity, aggregate stability index, soil hydraulic conductivity, and nutrient availability, thus reduces soil health. Consequently, it lowers crop performance via stunted aboveground growth coupled with reduced root growth. Therefore, if the characteristics of the soil are changed, it will affect the response of the structures. In this work, the effect of improving soil characteristics by compaction techniques on the dynamic response of foundations and structures, taking into consideration the effect of soil-structure interaction was determined. The dynamic response of foundations is presented by the impedances functions, which are determined numerically by the CONAN program, based on the cone method. In addition, the response of the structure will be presented according to the lateral displacement in each level of it. This motion vector is a function of the forces in each level; for this, the equivalent static method was applied, which allows to calculate the seismic force at the base and its distribution on the height of the structure. The results obtained show the efficiency of soil densification on the seismic response of MDOF frames.

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