Clastic soil is ubiquitous in practice but still poses challenges for testing and modelling. Conventional laboratory tests with small sizes are not suitable for the large grain size, while large-scale tests and field tests are often too costly and time-consuming. In this paper, the mechanical behaviour of clastic soil is described by a hypoplastic constitutive model based on numerical simulations considering both the soil matrix and breccia. The numerical simulations indicate that the breccia content, gradation, and overconsolidation ratio have a significant influence on the strength, deformation, and failure pattern of the clastic soil. The coarse particles are found to change the stress path developed in the soil matrix and consequently influence the critical state of the soil matrix. Moreover, the coarse particle distribution based on computed tomography scan seems to have a larger impact than the breccia content for the failure pattern of the clastic soils.
", "keywords": ["Civil and Environmental Engineering", "engrXiv|Engineering|Civil and Environmental Engineering|Civil Engineering", "Engineering", "engrXiv|Engineering", "bepress|Engineering|Civil and Environmental Engineering", "bepress|Engineering", "engrXiv|Engineering|Civil and Environmental Engineering", "0211 other engineering and technologies", "02 engineering and technology", "bepress|Engineering|Civil and Environmental Engineering|Civil Engineering", "Civil Engineering"]}, "links": [{"href": "https://www.icevirtuallibrary.com/doi/pdf/10.1680/jgeot.20.P.184"}, {"href": "https://doi.org/10.1680/jgeot.20.p.184"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/G%C3%A9otechnique", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1680/jgeot.20.p.184", "name": "item", "description": "10.1680/jgeot.20.p.184", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1680/jgeot.20.p.184"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-04-15T00:00:00Z"}}, {"id": "10.3390/su13073732", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-21T16:19:32Z", "type": "Journal Article", "created": "2021-03-26", "title": "The Optimisation Analysis of Sand-Clay Mixtures Stabilised with Xanthan Gum Biopolymers", "description": "Sand\uffe2\uff80\uff93clay mixtures can be encountered in both natural soils (e.g., residual soils, clay deposits and clinosols) and artificial fills. The method of utilising biopolymers in ground improvement for sand\uffe2\uff80\uff93clay mixtures has emerged recently. However, a full understanding of the strengthening effect of biopolymer-treated sand\uffe2\uff80\uff93clay mixtures has not yet been achieved due to a limited number of relevant studies. In this study, xanthan gum (XG), as one of the eco-friendly biopolymers, was used to treat reconstituted sand\uffe2\uff80\uff93clay mixtures that had various compositions in related to clay (or sand) content and clay type (kaolin and bentonite). A series of laboratory unconfined compression strength (UCS) tests were conducted to probe the performances of XG-treated sand\uffe2\uff80\uff93clay mixtures from two aspects, i.e., optimum treatment conditions (e.g., XG content and initial moisture content) to achieve the maximum strengthening effect and strengthening efficiency for the sand\uffe2\uff80\uff93clay mixtures with different compositions. The experimental results indicated that the optimum initial moisture content decreased as the sand content increased. The optimum XG content, which also decreased with the increasing sand content, remained approximately 3.75% for all sand\uffe2\uff80\uff93kaolin mixtures and 5.75% for all sand\uffe2\uff80\uff93bentonite mixtures if calculated based on clay fraction. While untreated sand\uffe2\uff80\uff93kaolin mixtures and sand\uffe2\uff80\uff93bentonite mixtures had comparable UCS values, XG-treated sand\uffe2\uff80\uff93kaolin mixtures seemed to have better improved mechanical strength due to higher ionic (or hydrogen) bonds with XG and low-swelling properties compared with bentonite. The deformation modulus of XG-treated sand\uffe2\uff80\uff93clay mixtures were positively related with UCS. The variation in UCS and stiffness for each treatment condition increased as the sand content was elevated for both sand-kaolin and sand-bentonite mixtures. An increment in the proportion of the heterogeneous composite formed by irregular sand particles conglomerated with the XG\uffe2\uff80\uff93clay matrix in total soil might be responsible for this phenomenon.
", "keywords": ["Civil and Environmental Engineering", "TP", "initial moisture content", "engrXiv|Engineering|Civil and Environmental Engineering|Civil Engineering", "bepress|Engineering", "bentonite", "xanthan gum", "QK", "TN", "0211 other engineering and technologies", "sand-clay mixture", "02 engineering and technology", "uniaxial compressive strength tests", "bepress|Engineering|Civil and Environmental Engineering|Civil Engineering", "Civil Engineering", "6. Clean water", "Engineering", "engrXiv|Engineering", "TA", "bepress|Engineering|Civil and Environmental Engineering", "engrXiv|Engineering|Civil and Environmental Engineering", "QE", "kaolin", "biopolymer content"], "contacts": [{"organization": "Geng, Xueyu, Ma, Lei, Hao, Gang-Lai, Ni, Jing, Chen, Jia-Qi,", "roles": ["creator"]}]}, "links": [{"href": "http://wrap.warwick.ac.uk/150469/7/WRAP-Optimisation-analysis-sand-clay-mixtures-stabilised-xanthan-gum-biopolymers-2021.pdf"}, {"href": "http://www.mdpi.com/2071-1050/13/7/3732/pdf"}, {"href": "https://www.mdpi.com/2071-1050/13/7/3732/pdf"}, {"href": "https://doi.org/10.3390/su13073732"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Sustainability", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3390/su13073732", "name": "item", "description": "10.3390/su13073732", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3390/su13073732"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2021-03-26T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=bepress%7CEngineering%7CCivil+and+Environmental+Engineering%7CCivil+Engineering&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=bepress%7CEngineering%7CCivil+and+Environmental+Engineering%7CCivil+Engineering&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=bepress%7CEngineering%7CCivil+and+Environmental+Engineering%7CCivil+Engineering&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=bepress%7CEngineering%7CCivil+and+Environmental+Engineering%7CCivil+Engineering&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-09-21T22:47:57.444819Z"}