scholarly journals Refinement of the Hardening Soil model within the small strain range

2020 ◽  
Vol 15 (8) ◽  
pp. 2031-2051 ◽  
Author(s):  
Marcin Cudny ◽  
Andrzej Truty
Author(s):  
Георгий Владимирович Мосолов ◽  
Илья Леонидович Димов

Уже в ближайшем будущем от использования современных численных методов расчета будет зависеть прогресс в области проектирования оснований и фундаментов зданий и сооружений, поскольку возможности по совершенствованию строительных норм практически исчерпаны. Целью статьи является демонстрация возможностей численных расчетов с использованием современных моделей грунта на примере проектирования фундамента стандартного нефтяного резервуара для хранения нефти и нефтепродуктов. Приведено сравнение результатов расчетов осадки основания резервуара емкостью 30 000 м, выполненных в соответствии с действующими нормами проектирования и методом конечных элементов с применением программного комплекса PLAXIS. В частности, проведены численные расчеты с использованием современных моделей грунта: 1) модели грунта с упрочнением (Hardening Soil model, HS); 2) модели грунта с упрочнением и учетом малых деформаций (Hardening Soil small strain model, HSs). Показано, что использование указанных моделей при наличии требуемого объема исходных данных позволяет существенно уточнить вычисления, выполняемые по нормативным методикам. С учетом полученных результатов определена возможность оптимизации проектных решений при выборе типа фундамента резервуара. In the near future, the progress in design of bases and foundations of buildings and structures will depend on the use of modern numerical calculation methods since the opportunities to improve the building regulations are almost exhausted. This article aims to demonstrate the capabilities of numerical calculations with the use of modern soil models on the example of designing the foundation of a standard oil storage tank for crude oil and petroleum products. This article provides a comparison of the results of the base settlement of a 30,000 m tank calculations made in accordance with the current standards of design and the finite elements method with the use of the PLAXIS software package. In particular, the following numerical calculations with the use of modern soil models have been performed: 1) Hardening Soil model, HS; 2) Hardening Soil small strain model, HSs. It is shown that the use of these models in the presence of the required amount of baseline data can significantly refine the calculations performed according to normative methods. Considering the obtained results, the possibility of optimizing design solutions when selecting the type of foundation of a tank was determined.


Author(s):  
Heitor Cardoso Bernardes ◽  
Maurício Martines Sales ◽  
Romulo Rodrigues Machado ◽  
Aleones José da Cruz Junior ◽  
Renato Pinto da Cunha ◽  
...  

Author(s):  
Katarzyna Markowska-Lech ◽  
Wojciech Sas ◽  
Mariusz Lech ◽  
Katarzyna Gabryś ◽  
Alojzy Szymański

Abstract The shear modulus of soils at small strain (G0) is one of the input parameters in a finite element analysis with the hardening soil model with small strain stiffness, required in the advanced numerical analyses of geotechnical engineering problems. The small strain stiffness can be determined based on the seismic wave velocities measured in the laboratory and field tests, but the interpretation of test results is still under discussion because of many different factors affecting the measurements of the wave travel time. The recommendations and proposed solutions found in the literature are helpful as a guide, but ought to be adopted with a certain measure of care and caution on a case-by-case basis. The equipment, procedures, tests results and interpretation analyses of bender elements (BE) tests performed on natural overconsolidated cohesive soils are presented.


Author(s):  
Raksiri Sukkarak ◽  
Suched Likitlersuang ◽  
Pornkasem Jongpradist ◽  
Pitthaya Jamsawang

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Hadianti Muhdinar Pasaribu

Banyaknya pembangunan infrastruktur yang merupakan salah satu tolak ukur kemajuan suatu daerah menyebabkan terjadinya penyempitan lahan didaerah tersebut. Sehingga pemanfaatan ruang dan lahan sangat dibutuhkan untuk menunjang kemajuan pesatnya pembangunan infrastruktur. Salah satu inovasi terbaik dalam mengatasi masalah keterbatasan lahan adalah membuat bangunan bawah tanah sehingga memberi ruang yang lebih untuk pembangunan. Pembangunan yang cukup terbaru di Indonesia saat ini adalah pembangunan MRT (Mass Rapid Transit) yang dilakukan di Jakarta. Pembangunan ini dalam pelaksanaannya membutuhkan proses konstruksi terowongan (tunneling) dan galian dalam untuk tiap stasiunnya. Pada penelitian ini, penulis terpusat terhadap masalah galian dalam pada stasiun Senayan dari proyek konstruksi MRT Jakarta. Permasalahan terbesar dalam suatu pekerjaan galian dalam adalah adanya deformasi lateral pada dinding bangunan bawah tanah dalam hal ini yang digunakan adalah dinding diafragma (D-Wall) dan juga adanya penurunan tanah disekitar galian. Oleh karena itu, perlu dilakukan pengecekan agar tidak terjadi keruntuhan. Metode konstruksi yang digunakan pada stasiun Senayan adalah metode konstruksi Top-Down. Pada penelitian ini dilakukan analisis deformasi horizontal dan penurunan tanah menggunakan software Plaxis 3D dengan dua pemodelan tanah, yaitu model tanah Mohr Coulomb dan Hardening Soil. Hasil deformasi horizontal yang diperoleh menggunakan model tanah Hardening Soil lebih mendekati  monitoring dilapangan dibandingkan dengan model tanah Mohr-Coulomb. Penelitian ini berfokus pada bagian-bagian tepi pada dinding diafragma melengkapi jurnal sebelumnya yang berfokus pada titik tengah dari dinding diafragma. Besarnya deformasi horizontal pada tahap akhir galian (penimbunan kembali tanah hingga dasar muka tanah) di titik P#80 (di tepi dinding diafragma) tercatat pada monitoring inclinometer sebesar 4.15 mm, dan deformasi yang dihasilkan menggunakan model Hardening Soil sebesar 9.57 mm sedangkan  menggunakan model Mohr-Coulomb sebesar 16.05 mm. Hasil deformasi horizontal yang diperoleh menggunakan model tanah Hardening Soil lebih mendekati  monitoring dilapangan dibandingkan dengan model tanah Mohr-Coulomb meskipun hasil yang diperoleh cukup jauh dari monitoring dilapangan.  Kata Kunci : Galian Dalam, Deformasi Horizontal, Model Mohr Coulomb, Model Hardening Soil, Plaxis 3D  The number of infrastructure development which is one of the benchmarks of the progress of a region causes the narrowing of land in the area. So that the utilization of space and land is needed to support the rapid progress of infrastructure development. One of the best innovations in overcoming the problem of land limitations is to make the underground building giving more space for development. The most recent development in Indonesia today is the construction of MRT (Mass Rapid Transit) conducted in Jakarta. This development in its implementation requires tunneling and deep trenching process for each station. In this study, the authors centered on the deep trenching problems at the Senayan station from the Jakarta MRT construction project. The biggest problem in a deep trenching work is the lateral deformation of underground building walls in this case which is used diaphragm wall (D-Wall) and also the decrease of soil around the excavation. Therefore, it is necessary to check to avoid collapse. The construction method used in Senayan station is a Top-Down construction method. In this research, horizontal deformation and soil degradation analysis using Plaxis 3D software with two soil modeling, Mohr Coulomb and Hardening Soil soil model. The result of the horizontal deformation obtained using Soil Hardening Soil model is closer to monitoring the field compared to the Mohr-Coulomb soil model. This study focuses on the edges of the diaphragm wall complementing the previous journal focusing on the midpoint of the diaphragm wall. The magnitude of the horizontal deformation at the final stages of excavation (backfill) to P # 80 (on the edge of the diaphragm wall) was recorded in inclinometer monitoring of 4.15 mm, and the resulting deformation using the Hardening Soil model of 9.57 mm while using the Mohr model -Coulomb of 16.05 mm. The horizontal deformation results obtained using the Soil Hardening Soil model is closer to the field monitoring than the Mohr-Coulomb soil model although the results obtained are quite far from the field monitoring.Keywords: Deep Excavation, Horizontal Deformation, Mohr Coulomb Model, Hardening Soil Model, Plaxis 3D.


Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1127
Author(s):  
Emil Soból ◽  
Katarzyna Gabryś ◽  
Karina Zabłocka ◽  
Raimondas Šadzevičius ◽  
Rytis Skominas ◽  
...  

The shear modulus and normalized shear modulus degradation curve are the fundamental parameters describing soil behavior. Thus, this article is focused on the stiffness characteristic of 15 different Warsaw cohesive soli represented by the parameters mentioned above. In this research, standard resonant column tests were performed in a wide shear strain range, from a small one, where soil behaves like an elastic medium, to a medium one, where soil has an unrecoverable deformation. Collected data allows the authors to create empirical models describing stiffness characteristics with high reliability. The maximum shear modulus calculated by the proposed equation for Warsaw cohesive soil had a relative error of about 6.8%. The formula for normalized shear modulus estimated G/GMAX with 2.2% relative error. Combined empirical models for GMAX, and G/GMAX allow the evaluation of Warsaw cohesive soil’s shear modulus value in a wide shear deformation range, with a very low value of the relative error of 6.7%.


Author(s):  
W. B. Gookin ◽  
M. F. Riemer ◽  
R. W. Boulanger ◽  
J. D. Bray

A cyclic triaxial testing system capable of measuring very small to large strain properties on a single specimen has been developed by combining a wide variety of existing instrumentation, including piezoceramic bender elements, internal displacement measurement devices (both contact and noncontact), local displacement measurement devices, a sensitive internal load cell, and an external load cell. The bender elements provide information on soil properties in the nearly linear elastic (very small strain) range. Local and noncontact internal displacement measurements provide information about small strain range properties, whereas more traditional internal displacement measurements provide information in the small to large strain range. In addition, this apparatus can be used over a wide range of loading frequencies to investigate the effect of frequency on dynamic soil properties. By combining this equipment in a single testing system, a number of tests may be run on one specimen, eliminating the effects of variability. The broad variety of displacement measuring instruments also allows direct comparisons of these techniques on a single specimen.


2019 ◽  
Vol 7 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Jonathan T. H. Wu ◽  
Sheldon Chih-Yu Tung

Sign in / Sign up

Export Citation Format

Share Document