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The bounding effect of the water retention curve on the cyclic response of an unsaturated soil (2022)
Journal Article
Azizi, A., Kumar, A., & Toll, D. G. (2023). The bounding effect of the water retention curve on the cyclic response of an unsaturated soil. Acta Geotechnica, 18(4), 1901-1917. https://doi.org/10.1007/s11440-022-01724-0

The water retention properties of soils present in formation layers of roads and railways continuously vary due to repeated traffic loads and periodic rainfall events. This is important because the accumulated deformation and resilient modulus of suc... Read More about The bounding effect of the water retention curve on the cyclic response of an unsaturated soil.

An investigation of the combined effect of rainfall and road cut on landsliding (2022)
Journal Article
Pradhan, S., Toll, D., Rosser, N., & Brain, M. (2022). An investigation of the combined effect of rainfall and road cut on landsliding. Engineering Geology, 307, Article 106787. https://doi.org/10.1016/j.enggeo.2022.106787

The reduction of soil suction and consequent loss of shear strength due to infiltration is known to trigger shallow landslides during periods of concentrated rainfall. In the mountainous terrain of Nepal, the risk of shallow rainfall-induced landslid... Read More about An investigation of the combined effect of rainfall and road cut on landsliding.

Reusing Fe water treatment residual as a soil amendment to improve physical function and flood resilience (2022)
Journal Article
Kerr, H. C., Johnson, K. L., & Toll, D. G. (2022). Reusing Fe water treatment residual as a soil amendment to improve physical function and flood resilience. SOIL, 8(1), 283-295. https://doi.org/10.5194/soil-8-283-2022

Soil degradation is a global challenge that is intrinsically linked to climate change and food security. Soil degradation has many causes, but all degraded soils suffer from poor soil structure. The increasing global production of water treatment res... Read More about Reusing Fe water treatment residual as a soil amendment to improve physical function and flood resilience.

The mechanical properties of a high plasticity expansive clay (2022)
Journal Article
Gaspar, T., Jacobsz, S., Heymann, G., Toll, D., Gens, A., & Osman, A. (2022). The mechanical properties of a high plasticity expansive clay. Engineering Geology, 303, https://doi.org/10.1016/j.enggeo.2022.106647

The mechanical properties of a high plasticity expansive clay from South Africa are reported. The experimental programme considered wetting after loading tests followed by one-dimensional consolidation and unloading of undisturbed and statically comp... Read More about The mechanical properties of a high plasticity expansive clay.

The Influence of Cyclic Loading Frequency on the Response of an Unsaturated Railway Formation Soil (2022)
Conference Proceeding
Kumar, A., Azizi, A., & Toll, D. (2022). The Influence of Cyclic Loading Frequency on the Response of an Unsaturated Railway Formation Soil. In A. Lemnitzer, & A. W. Stuedlein (Eds.), Geo-Confress 2022: Geoenvironmental Engineering; Unsaturated Soils; and Contemporary Topics in Erosion, Sustainability, and Coal Combustion Residuals (274-283). https://doi.org/10.1061/9780784484050.029

This paper presents the results of cyclic triaxial tests conducted on unsaturated soil samples recovered from the railway embankment of a South African coal line to investigate the influence of cyclic loading frequency on a formation layer material,... Read More about The Influence of Cyclic Loading Frequency on the Response of an Unsaturated Railway Formation Soil.

Application of suction monitoring for cyclic triaxial testing of compacted soils (2022)
Journal Article
Kumar, A., Azizi, A., & Toll, D. (2022). Application of suction monitoring for cyclic triaxial testing of compacted soils. Journal of Geotechnical and Geoenvironmental Engineering, 148(4), https://doi.org/10.1061/%28asce%29gt.1943-5606.0002766

The performance of compacted soils that are used for the construction of railway embankments are impacted by weather-driven suction and water content fluctuations. Hence, the accurate measurement of the water retention properties of soil during cycli... Read More about Application of suction monitoring for cyclic triaxial testing of compacted soils.

Coupling cyclic and water retention response of a clayey sand subjected to traffic and environmental cycles (2021)
Journal Article
Azizi, A., Kumar, A., & Toll, D. G. (2023). Coupling cyclic and water retention response of a clayey sand subjected to traffic and environmental cycles. Géotechnique, 73(5), 401-417. https://doi.org/10.1680/jgeot.21.00063

Compacted soils used as formation layers of railways and roads continuously undergo water content and suction changes due to seasonal variations. Such variations, together with the impact of cyclic traffic-induced loads, can alter the hydro-mechanica... Read More about Coupling cyclic and water retention response of a clayey sand subjected to traffic and environmental cycles.

Predictive and prescriptive analytics in transportation geotechnics: Three case studies (2021)
Journal Article
Tinoco, J., Parente, M., Gomes Correia, A., Cortez, P., & Toll, D. (2021). Predictive and prescriptive analytics in transportation geotechnics: Three case studies. Transportation Engineering, 5, Article 100074. https://doi.org/10.1016/j.treng.2021.100074

Transportation infrastructure is of paramount importance for any country. The construction, management and maintenance of this infrastructure is a complex task that requires a significant amount of resources (e.g., human work equipment, materials, ma... Read More about Predictive and prescriptive analytics in transportation geotechnics: Three case studies.

Advanced analysis of satellite data reveals ground deformation precursors to the Brumadinho Tailings Dam collapse (2021)
Journal Article
Grebby, S., Sowter, A., Gluyas, J., Toll, D., Gee, D., Athab, A., & Girindran, R. (2021). Advanced analysis of satellite data reveals ground deformation precursors to the Brumadinho Tailings Dam collapse. Communications Earth & Environment, 2, Article 2. https://doi.org/10.1038/s43247-020-00079-2

Catastrophic failure of a tailings dam at an iron ore mine complex in Brumadinho, Brazil, on 25th January 2019 released 11.7 million m3 of tailings downstream. Although reportedly monitored using an array of geotechnical techniques, the collapse occu... Read More about Advanced analysis of satellite data reveals ground deformation precursors to the Brumadinho Tailings Dam collapse.

Weather-driven deterioration processes affecting the performance of embankment slopes (2020)
Journal Article
Stirling, R., Toll, D., Glendinning, S., Helm, P., Yildiz, A., Hughes, P., & Asquith, J. (2021). Weather-driven deterioration processes affecting the performance of embankment slopes. Géotechnique, 71(11), 957-969. https://doi.org/10.1680/jgeot.19.sip.038

Deterioration of earthworks and the resultant implications for serviceability and increased occurrence of failures have a significant negative impact on transport networks both in the UK and internationally. There is evidence in the field that deteri... Read More about Weather-driven deterioration processes affecting the performance of embankment slopes.

Field monitoring of soil-moisture to understand the hydrological response of a road-cut slope (2020)
Book Chapter
Pradhan, S., Toll, D., Rosser, N., & Brain, M. (2020). Field monitoring of soil-moisture to understand the hydrological response of a road-cut slope. In R. Cardoso, C. Jommi, & E. Romero (Eds.), 4th European Conference on Unsaturated Soils (E-UNSAT 2020). EDP Sciences. https://doi.org/10.1051/e3sconf/202019501029

Rainfall and slope-cutting for road construction are two key landslide causative factors in Nepal, but how they interact to cause failures is poorly understood. To improve understanding of the effects of cut slopes during rainfall, geotechnical inves... Read More about Field monitoring of soil-moisture to understand the hydrological response of a road-cut slope.

Experimental, numerical and field study investigating a heritage structure collapse after the 2015 Gorkha earthquake (2020)
Journal Article
Kumar, A., Hughes, P. N., Sarhosis, V., Toll, D., Wilkinson, S., Coningham, R., …Maskey, P. N. (2020). Experimental, numerical and field study investigating a heritage structure collapse after the 2015 Gorkha earthquake. Natural Hazards, 101(1), 231-253. https://doi.org/10.1007/s11069-020-03871-7

This paper presents an investigation of the collapse of a 325-year-old multi-tiered heritage temple during the 2015 Gorkha earthquake in Kathmandu, Nepal. The research comprises a reconnaissance survey followed by a geotechnical investigation and num... Read More about Experimental, numerical and field study investigating a heritage structure collapse after the 2015 Gorkha earthquake.

Identifying archaeological evidence of past earthquakes in a contemporary disaster scenario: Case-studies of damage, resilience and risk reduction from the 2015 Gorkha Earthquake and past seismic events within the Kathmandu Valley UNESCO World Heritage Property (Nepal) (2019)
Journal Article
Davis, C., Coningham, R., Acharya, K., Kunwar, R., Forlin, P., Weise, K., …Schmidt, A. (2020). Identifying archaeological evidence of past earthquakes in a contemporary disaster scenario: Case-studies of damage, resilience and risk reduction from the 2015 Gorkha Earthquake and past seismic events within the Kathmandu Valley UNESCO World Heritage Property (Nepal). Journal of Seismology, 24(4), 729-751. https://doi.org/10.1007/s10950-019-09890-7

The 2015 Gorkha Earthquake was a humanitarian disaster but also a cultural catastrophe that damaged and destroyed historic monuments across Nepal, including those within the Kathmandu Valley UNESCO World Heritage Property. In the rush to rebuild, tra... Read More about Identifying archaeological evidence of past earthquakes in a contemporary disaster scenario: Case-studies of damage, resilience and risk reduction from the 2015 Gorkha Earthquake and past seismic events within the Kathmandu Valley UNESCO World Heritage Property (Nepal).

Reducing Disaster Risk to Life and Livelihoods by Evaluating the Seismic Safety of Kathmandu’s Historic Urban Infrastructure: enabling an interdisciplinary pilot (2019)
Journal Article
Coningham, R., Acharya, K., Barclay, C., Barclay, R., Davis, C., Graham, C., …Wilson, A. (2019). Reducing Disaster Risk to Life and Livelihoods by Evaluating the Seismic Safety of Kathmandu’s Historic Urban Infrastructure: enabling an interdisciplinary pilot. Journal of the British Academy, 7(S2), 45-82. https://doi.org/10.5871/jba/007s2.045

Kathmandu’s cities are exceptional architectural and artistic achievements, underpinned by centuries of seismic adaptation. They represent portals where heavens touch the earth and individuals commune with guiding deities; their tangible and intangib... Read More about Reducing Disaster Risk to Life and Livelihoods by Evaluating the Seismic Safety of Kathmandu’s Historic Urban Infrastructure: enabling an interdisciplinary pilot.

On the development of an ultra-high-capacity tensiometer capable of measuring water tensions to 7 MPa (2019)
Journal Article
Mendes, J., Gallipoli, D., Tarantino, A., & Toll, D. (2019). On the development of an ultra-high-capacity tensiometer capable of measuring water tensions to 7 MPa. Géotechnique, 69(6), 560-564. https://doi.org/10.1680/jgeot.18.t.008

Tensiometers are increasingly used in geotechnical engineering to monitor pore-water tension in the field and to study the hydro-mechanical behaviour of unsaturated soils in the laboratory. Early tensiometers exhibited a relatively small measuring ra... Read More about On the development of an ultra-high-capacity tensiometer capable of measuring water tensions to 7 MPa.

Matric Suction and Volume Characteristics of Compacted Clay Soil under Drying and Wetting Cycles (2019)
Journal Article
Liu, G., Toll, D., Kong, L., & Asquith, J. (2020). Matric Suction and Volume Characteristics of Compacted Clay Soil under Drying and Wetting Cycles. Geotechnical Testing Journal, 43(2), 464-479. https://doi.org/10.1520/gtj20170310

The influence of drying and wetting cycles on matric suction and volume characteristics of a compacted low-plasticity clay soil was studied experimentally. An apparatus was developed in which soil specimens were placed in direct contact with a high-s... Read More about Matric Suction and Volume Characteristics of Compacted Clay Soil under Drying and Wetting Cycles.

First Saturation and Resaturation of High Capacity Tensiometers with 1.5 MPa High Air Entry Value (HAEV) Ceramic Filters (2018)
Conference Proceeding
Mendes, J., Gallipoli, D., Toll, D., & Tarantino, A. (2018). First Saturation and Resaturation of High Capacity Tensiometers with 1.5 MPa High Air Entry Value (HAEV) Ceramic Filters. In PanAm Unsaturated Soils 2017 (514-522). https://doi.org/10.1061/9780784481684.052

High capacity tensiometers, or HCTs, are sensors that can measure negative pore water pressures (soil suctions) between −1.5 and −2 MPa. To achieve such measured values, HCTs first need to be fully saturated by water. For the first saturation of an i... Read More about First Saturation and Resaturation of High Capacity Tensiometers with 1.5 MPa High Air Entry Value (HAEV) Ceramic Filters.

Data-Driven Model for Stability Condition Prediction of Soil Embankments Based on Visual Data Features (2018)
Journal Article
Tinoco, J., Gomes Correia, A., Cortez, P., & Toll, D. G. (2018). Data-Driven Model for Stability Condition Prediction of Soil Embankments Based on Visual Data Features. Journal of Computing in Civil Engineering, 32(4), Article 04018027. https://doi.org/10.1061/%28asce%29cp.1943-5487.0000770

Keeping large-scale transportation infrastructure networks, such as railway networks, operational under all conditions is one of the major challenges today. The budgetary constraints for maintenance purposes and the network dimension are two of the m... Read More about Data-Driven Model for Stability Condition Prediction of Soil Embankments Based on Visual Data Features.

Soil–atmosphere interactions for analysing slopes in tropical soils in Singapore (2018)
Journal Article
Toll, D. G., Rahim, M. S. M., Karthikeyan, M., & Tsaparas, I. (2019). Soil–atmosphere interactions for analysing slopes in tropical soils in Singapore. Environmental Geotechnics, 6(6), 361-372. https://doi.org/10.1680/jenge.15.00071

The modelling of soil–atmosphere interactions for slopes requires a proper understanding of the relevant soil parameters (soil water retention curve and the permeability function). This paper reports on numerical investigations of an instrumented res... Read More about Soil–atmosphere interactions for analysing slopes in tropical soils in Singapore.