Advance Characterization and Modeling of Geomaterials and Geosystems

The special collection on Advance Characterization and Modeling of Geomaterials and Geosystems is available in the ASCE Library (https://ascelibrary.org/page/ijgnai/characterization_modeling_geomaterials_geosystems).

More than any other time, engineers are facing the challenge of designing, constructing, and preserving the infrastructure system in a sustainable way. Economic prosperity and improved lifestyle are among the benefits of a resilient and sustainable infrastructure system. In civil infrastructures, sustainable materials play a major role in this regard. These could be from renewable resources or materials that are abundantly available, durable, and recyclable. This special collection titled “Advance Characterization and Modeling of Geomaterials and Geosystems” on the International Journal of Geomechanics selects 22 high-quality papers that address the aforementioned issues from theoretical basis to practical perspective. All papers published in this collection have undergone standard yet rigorous peer review, and their origins including four continents are regarded to have wide representativeness.

There are 12 papers that discuss a variety of issues related to tunneling. Ye et al. (2017) introduced a case study on using a new scheme to determine soil conditioning parameters that govern soil clogging that occurred in the early construction stage of earth balance pressure (EPB) shield tunneling. Wang et al. (2017b) presented a numerical analysis of the effect of a fault fracture zone on the stability of tunnel surrounding rocks. Noting that surrounding rock control is one of the major problems in deep underground engineering under the complicated conditions of high stress, tectonic fracture zones, and others, Li et al. (2017c) proposed a three-dimensional confined concrete support system (CCSS) to tackle this difficulty encountered in the construction. Based on the damage constitutive model, finite-element analysis was undertaken by Huang et al. (2017) to address the tunnel excavation damaged zone due to the increase in release ratio of displacement (RRD) in the rock mass surrounding a tunnel. Li et al. (2017d) studied the grouting diffusion characteristics in faults frequently adopted in rock-tunneling constructions. Wu et al. (2017) conducted a numerical simulation to investigate the flow characteristics and escape-route optimization after water inrush in a backward excavated karst tunnel. Li et al. (2017b) found that the instability of filling medium in large-scale filled-typed karst caves often induce mud inrush in tunnel construction, and an innovative method was proposed for the integral sliding stability analysis of the filling medium based on the simplified Bishop method.

The tunnel construction will induce considerable ground settlements. Noting the limitations of empirical and artificial intelligent methods, Zhou et al. (2017) proposed a random forest program and predicted ground settlement above tunnels. Mo and Yu (2017) predicted the tunnel-induced ground settlements using a cavity-contraction method integrated with an existing unified state parameter model for clay and sand (CASM). Zhang et al. (2017) presented an analytical calculation method to predict the tunnel deformation induced by upside excavation, and discussed the role of dewatering in the deformation mechanism. Yu et al. (2017) interpreted the microseismic data and data from hundreds of rockbursts of different intensities that occurred in a water drainage tunnel and four deep headrace tunnels. Shi et al. (2017) presented an investigation on the mechanical performance of a large-scale pipe roof used to pre-reinforce the surrounding ground and improve the stability of railway tunnels.

Four papers discuss the soil–structure (or pile) interactions using model experiments and numerical analyses. Xiao et al. (2017) performed model tests on the displacement characteristics of flat-ended piles, pipe piles, and piles with cone tips of 45° in transparent granular soils. Yuan et al. (2017) conducted a scaled-model test to investigate the deflection of a laterally loaded pile and soil deformation in loose sand. An optical experimental setup was developed to capture images of soil movement and the readings of strain gauges along the pile. Nguyen et al. (2017b) described a numerical modeling technique for the simulation of complex seismic soil–pile–structure interaction phenomena in Abaqus. Zhu et al. (2017) investigated the influence of the axial force and its distribution along the pile shaft on the response of laterally loaded piles. A generalized solution was proposed based on the transfer matrix approach, where the transfer matrix coefficients for pile in the free zone, elastic zone, and plastic zone were analytically obtained through Laplace transformation.

The topics of six other papers span a wide range of issues. Nguyen et al. (2017a) developed a critical-state framework based–constitutive model for cement-treated clay; Ghosh et al. (2017) proposed a mechanical model to idealize the settlement response of a load-transfer platform (LTP) on column-improved soft soil. AbdelSalam et al. (2017) investigated the mechanical properties of the geofoam or foam made of expanded polystyrene (EPS), which was widely used to substitute the soil backfills. Li et al. (2017a) used a detached eddy simulation (DES) numerical model to investigate the effect of pier streamlining on the intensity of dynamic turbulence around bridge piers, and discussed the implication of such an effect on bridge local scour potential from a geomechanical perspective. Wang and Li (2017) proposed a group of dynamic distribution models of voidage to investigate the heterogeneous distribution and dynamic change of longwall mining–induced voids in overlying strata of coalbed. Wang et al. (2017a) presented an experimental investigation into the strength characteristics of expansive soil reinforced with jute fiber. The beneficial role of jute fibers was demonstrated in enhancing the shear strength and reducing the loss of the postpeak strength of the expansive soils.