Gonghui Wang

Kyoto University | Kyodai · Disaster Prevention Research Institute

Drastic grain comminution is frequently observed in upper-crust faults and large rock avalanche deposits. Here we report our model experiments to elucidate the possible role of grain comminution in dry granular friction. We sheared halite (NaCl) grains with a ring-shear configuration at a constant slip rate under various normal stresses and investi...

We examined soil‐water response in a hillslope with multi‐layered volcanic soils affected by fissures formed by intense shaking during the 2016 Kumamoto earthquake in Japan. Pressure head and volumetric water content responses in a 6 × 20 m hillslope ridgeline plot were monitored by tensiometers and capacitance‐based soil moisture sensors, respecti...

A key motivation of this study is to better understand the physical processes that dictate the slow-to-fast transition of frictional behavior in earthquakes and landslides by combining the friction measurements and microscopic analysis of the experimental fault zone. We simplify the questions as (1) the effect of the comminution rate and segregatio...

Landslide movements exhibit an extensive spectrum of velocities in responses to changes in geometry, pore-water pressure, or strength of the soil. Apart from the most catastrophic events where landslides can travel at tens of meters per second, many landslides creep at a velocity ranging from millimeters to meters per year. The seemingly persistent...

Rainfall‐induced flowslides and the subsequent debris flows are the most recurrent and destructive natural hazards due to their high velocity and long‐distance runout. It is widely accepted that shear‐induced excess pore pressure controls the high fluidity in flowslide movement. Nevertheless, flume experiments demonstrate that flowslides can exhibi...

Earthquakes occur frequently in Japan, resulting in many casualties and great damage to properties. Landslides triggered by the earthquakes are a great threat to local properties and the lives of residents. In many cases, most of the casualties during the earthquake resulted from the coseismic landslides. In this report, we introduced those landsli...

This chapter presents a brief description of rockslides triggered by the historical earthquakes in the Central Asia region. Based on field survey and interpretation of space images, the location, scale, geological and topographic features of these rockslides, and some characteristics of related earthquakes are introduced. Several rockslides, whose...

This research evaluated numerically the effect of drainage wells on the response of landslides during earthquakes, taking the Ichiba No. 1 landslide, a coseismic landslide, as an example. The unsaturated–saturated finite element seepage analyses were carried out to evaluate the groundwater level lowered by the drainage wells. The dynamic total stre...

In Niigata, Japan, many landslides have occurred in Tertiary rocks. Although most of these landslides were slow-moving, some underwent catastrophic failure, and different types of landslides sometimes occurred nearby under almost identical geological and hydrological conditions, but their mechanisms remain unclear. This study introduces a landslide...

In 1881, the Swiss village of Elm was devastated by a rock avalanche that had originated two kilometers away. Geologist Albert Heim reported on the impressive event, prompting over a century of research on the extraordinary long runout of giant landslides. However, after one century of research, the answer to the question of why a dry mass can beha...

The residual strength of sliding basal soils plays a pivotal role not only in the movement of bedding landslides controlled by clay-rich interlayers but also in remobilized granular deposits. Many studies have focused on better understanding the residual shear behaviors of clayey and granular soils under relatively low shear rates. However, the res...

Heifangtai terrace is famous in China for its irrigation-induced loess landslides. The frequently recurring loess flowslides initiated along the platform margin of the irrigated Heifaingtai terrace have caused 42 fatalities and significant economic losses due to their long-runout and high-speed mobility. Yet it is still unclear if the recurring loe...

The natural blockage of river channels by landslide debris gives rise to a range of potentially adverse processes including complete or partial damming, backwater inundation and sedimentation, catastrophic outbursts of impounded lake waters and downstream river aggradation following dam failure. Most reports portray landslide dams as short-lived an...

The Daguangbao landslide was the most catastrophic mass movement triggered by the 2008 Wenchuan earthquake with a magnitude scale of Ms. 8.0. The landslide, which was 4.6 km long and 3.7 km wide, had a volume of approximately 1.2 × 10⁹ m³. Since its occurrence, many assumptions regarding its initiation and movement mechanisms have been made; howeve...

Many models have been proposed to forecast the time of failure of landslides, among them the Voight model (Ω¨=AΩ̇α) has been widely used. Values for controlling parameters of α and A, defined by accelerating movement, are representative of kinematic behavior prior to material failure. Nevertheless, due to the unknowns in the key parameters (α and A...

The evolution of sliding zone soil originating from a muddy interlayer in the Three Gorges Reservoir (TGR) in China is accompanied by an increase in clay content, and the subsequent changes in its mechanical properties control the initiation or reactivation of large-scale bedrock landslides. In this paper, using sliding zone soil samples from the X...

River-damming by landslides is a widespread phenomenon around the world. Recent advances in remote sensing technology and the rising commercial availability of their products enable the assemblage of increasingly more complete inventories and improve monitoring efforts. On the ground, multi-method dating campaigns enhance our understanding of the t...

A volcanic slope in Izu Oshima Island in Japan experienced a profound rain-induced disaster in October 2013. Since this slope had been stable for centuries except for minor failures, a special investigation was carried out on the cause. Because of its volcanic origin, the failed slope consisted of layers of ash, sand and lava. While the investigati...

Rapid landsliding phenomena demonstrate that their constituent grains can flow with extremely low friction along their runout paths. Over the past several decades, many studies have been motivated to reveal such kind of unusual physical process; however, the progressive maturation of these events is still lack of enough scientific evidence. Modern...

A large, catastrophic landslide took place on Ono area in Oita Prefecture, southwest Japan, triggered by extraordinarily heavy rain on July 5-6, 2017. Seismic waves triggered by this landslide were captured by high sensitivity seismometers in the routine seismic network. The signals consisted of two packets of seismic waves, and the latter one was...

In 2008, the Wenchuan earthquake triggered many large landslides with rapid movement and long runouts, resulting in a great number of casualties. Although there have been many studies of the geographical features and initiation mechanisms of some catastrophic landslides, the movement mechanisms for many remain unclear. In this paper, we present a c...

The surface displacements of slopes have been considered as a significant indicator in landslide investigations in last several decades, while in recent years the tilting of slope surfaces is also being recognized as an important index in landslide monitoring. However, the slope surface tilting has been rarely examined so far, and requires detailed...

In recent decades, early warning systems using tilt sensors to predict the occurrence of landslides have been developed and employed in slope monitoring due to the simple installation and low cost of these systems. However, few studies were carried out to investigate the tilting behaviors of landslides, and the prediction methods for the occurrence...

The writers are grateful to the discussers for the interest shown in their work. Kenney and Lau (1985) provided an empirical criterion for instability based on experiences on dense soils. Accordingly, the slope of the secant of the grain size distribution curve of a stable soil in the F(d)-d plane (where F(d) is the passing fraction in mass, expres...

The territory of Azad Jammu and Kashmir (AJK) is vulnerable to different natural hazards because of its proximity to a geo-dynamically active zone and its tropical and monsoonal climatic pattern. Both factors operate in various combinations and result in the occurrence of disasters generated by natural hazards like floods, earthquakes, and landslid...

Heavy rainfall and strong wind associated with Typhoon Wipha hit Izu-Oshima Island, Japan, and triggered catastrophic landslides on the western slope of Oshima Volcano on 16 October 2013. These landslides were shallow but large in scale, and the displaced landslide materials were characterized by rapid and long runout movement. A massive landslide...

To better understand seismic site responses of deep-seated landslides, we carried out long-term seismic monitoring of a target landslide reactivated by a rainstorm in 2004 accompanying Typhoon Namtheun in Naka Town, Tokushima Prefecture, Japan. Five seismometers with high sensitivity were installed at different locations on landslide areas with dif...

Field and monitoring evidences show that deformation in a rockslide is predominantly localized along a basal shear zone. Mineralogic, grain size, thickness, and fabric characteristics of the shear zone control its behavior and the possible evolution of the rockslide from a slow creeping to a fast moving one. Standard experimental tests can characte...

To study the distribution and variation of dynamic soil pressures in reinforced soil slopes and the effectiveness of different stabilizing structure types, we conducted a series of shaking table tests on soil slopes reinforced by two types of stabilizing structures: constrained anti-slide pile (beam-pile) and pre-stressed anchor slab-pile walls (an...

The 2016 Kumamoto earthquake, which occurred in the central Kyushu region of Southwest Japan, caused numerous landslides. Mass movements from the events damaged many structures in the Minami-aso village residential areas. We conducted geological and geophysical surveys and monitoring of landslides in one of these residential areas. It was found tha...

As for the groundwater in the area of landslide, to know the source of it, the place to where the groundwater flows in and the distribution of the groundwater vein lead to the well understanding of the effect of groundwater on the landslide activities and subsequently to the reasonable planning of drainage works. In this article, authors deal with...

The iRALL, the International Research Association on Large Landslides, is a non-governmental, non-political, non-profit organisation that promotes research and knowledge on large landslides and gives particular attention to the chain of geohazards in earthquake-affected areas. The association was founded on 17 November 2015 and benefits of a presti...

Improving the performance of loess is of significant importance for lowering its collapsibility and water sensitivity to construction requirements and for geohazard mitigation. The present paper studies the changes in mechanical, structural, and mineralogical properties of nano-SiO 2-treated loess with different contents and curing days. The mechan...

Evidence suggests soil particles undergo changes of size, shape and surface roughness with shearing. By means of quantitative descriptors, the particle size, shape, and particle surface roughness are investigated in natural soils and model granular materials subjected to shear. An investigation is made for igneous rocks-derived soil particles in Ho...

A paper, which was recently published in Journal of Mountain Science by Cui et al. (2017), reported a series of laboratory flume experiments designed to illuminate the moving characteristics of fine particles for wide grading unconsolidated soils by considering three factors, slope gradient, rainfall duration and rainfall intensity. This commentary...

Every year, Australia experiences tropical cyclones that bring large amounts of rainfall, causing flooding and damage to infrastructure and road closure due to landslips. In March 2017, tropical cyclone Debbie hit the Queensland coast dumping 747 mm of rainfall within 2 days to the Gold Coast region. As a result, multiple shallow landslides occurre...

Most landslides on the Loess Tableland (Shaanxi, China) are of the sliding-flow type, with long run-out distances. These landslides, which tend to be triggered by irrigation, result in loss of life and damage to infrastructure. In order to reveal the characteristics and mechanisms of sliding-flow landslides, field investigations, surveys and indoor...

Landslides are the mass of rock, debris and or earth that moves down a slope by gravity. Study on landslide dynamics, including the dynamic of loading and excess pore-pressure generation and dissipation, is necessary to understand the initiation and motion of rapid landslides. This paper presents the development of ring shear apparatus that can fac...

Largely unknown mechanisms restrain motion of clay-rich, slow-moving landslides that are widespread worldwide and rarely accelerate catastrophically. We studied a clayey, slow-moving landslide typical of thousands in Northern California, USA, to decipher hydrologic-mechanical interactions that modulate landslide dynamics. Similar to some other stud...

Fluidized landslides are one of the most dangerous types of mass movements as they can run over long distances at high velocity. A flow-like landslide can occur in both artificially designed and natural slopes, resulting in extensive property damage and significant loss of lives. Although various studies have examined the initiation mechanism of th...

A great number of landslides were triggered during the 2008 Wenchuan earthquake. Among them, the Niumiangou landslide is the large-scale landslide in the epicenter area. The site investigation shows that the landslide mass collides to the NE side of the valley immediately after initiation. The moving velocity estimated is 19.8 m/s, suggesting the c...

We present results of ring-shear frictional resistance for mudstone granules of different size obtained from a landslide shear zone. Little rate dependency of shear resistance was observed in sand-sized granules in any wet or dry test, while saturated gravel-sized granules exhibited significant and abrupt reversible rate-weakening (from μ = 0.6 to...

In Nakahara, a residential area in Mifune Town, serious damage was caused by the 2016 Kumamoto earthquake sequence. To better understand the mechanism of the damage, it is necessary to have a better understanding on the seismic response of the residential area during the foreshock and the main shock with high accuracy by taking into account site ef...

In the northwest of China, many loess landslides have occurred without clear triggering factors (i.e., rainfall, earthquake, human activities, etc.). To better understand and analyze the hydro-mechanical properties of these slopes and then provide evidence for their stability analysis subjected to matric suction, it is essential to clarify the soil...

All around the world, ancient legends exist about the Great Flood, and the influence of the Great Flood in human evolutionary history is a hotly debated topic. In China, the legend of the prehistoric Great Flood and Yu the Great’s flood control has a long history and is considered to be closely linked to the establishment of the Xia Dynasty. Howeve...

In this study, we performed the 1-m-depth ground temperature survey and continuous ground temperature monitoring at the Zentoku landslide area and the Nishi-ikawa landslide in the crystalline schist mountains to clarify the actual groundwater flow in landslide slopes. Our results showed that the ground temperatures at differing locations of the slo...

In order to elucidate the behavior of a slope during earthquake shaking, we developed a new integrated sensor of accelerometer and inclinometer. The sensor was designed to need a small amount of electricity supply and be water- and pressure-proofed at a depth of 100 m so that it is installed into the boreholes in mountainous slope areas. Setting th...

The high mobility of rapid landslides is one of the most important subjects of both theoretical and practical interest to engineers and scientists. The idea that ultralow resistance could explain the high mobility inspires researchers to examine the shear behavior of granular materials under a wide range of conditions, but the response of granular...

Residential landslides in Miami-Aso Village, which are located near the epicenter of the main shock of the 2016 Kumamoto Earthquake were occurred due to the strong motion. In this study, ground investigations were conducted at the landslide sites in order to evaluate the empirical site effects. Seismic waveforms at the sites of interest during the...

Fluidized landslides that travel long distances at high speed are one of the most dangerous types of landslides. A fluidized slope movement can occur in both artificially designed slopes and natural slopes and generally results in extensive property damage and significant loss of life. However, the initiation mechanisms triggering this type of land...

On Oct. 16, 2013, catastrophic shallow landslides were triggered on the west-side hillslopes in Izu-Oshima Island, Japan, by the heavy rainfall accompanying Typhoon Wipha. The displaced landslide materials were characterized by rapid and long runout movement. These landslides resulted in 36 dead, 3 missing, and 46 buildings being completely destroy...

The Heifangtai is located on the fourth terrace of the Yellow River, c . 60 km to the west of Lanzhou City, Gansu Province, China (Fig. 1a). The terrace has an area of 13.7 km2 and, since the 1960s, has been used as farmland by the people relocated from areas affected by the construction of the Liujiaxia Dam and its associated reservoir on the Yell...

The South Jingyang Plateau, with a total area of 70 km², is located in Shaanxi Province, China. Since 1976, more than 50 landslides of different types have occurred repeatedly on the edge slopes of the plateau due to the start of diversion irrigation on the plateau, resulting in great loss of lives and property. To better understand the initiation...

Every year about one third of the geohazards in China occur in the Loess Plateau causing human loss, damaging gas and oil pipelines, destroying highways, railways and degrading farmland. Field investigation and monitoring, in-situ tests and laboratory experiments were performed to improve our understanding of the factors effecting the distribution,...

The generation of acoustic emission (AE) in a material relates to the rapid energy release process, which delivers important information concerning the failure mechanism for stressed geologic materials. Here we report on ring-shear friction experiments to investigate the mechanical behavior and AEs for sheared granular materials with different part...

The 1920 Haiyuan Ms 8.5 earthquake induced a large number of fluidized loess landslides in China, characterized by low slope angles, long run-out distances, and fluidized movement. The mechanism of these landslides has aroused considerable interest, although additional research is needed to understand more fully the behavior of the loess and the fa...

The Daguangbao (DGB) landslide which triggered by the 2008 Wenchuan earthquake is one of the largest earthquake-triggered landslides in the world over the past century. In this study, remote sensing images analysis, field investigation, laboratory experiment and slope stability analysis were adopted to characterize this DGB landslide. We speculated...

The Niumiangou landslide (~7.5 × 10⁶ m³) was the largest that occurred in the town of Yingxiu (the epicentral area) during the 2008 Wenchuan earthquake. This landslide originated on a steep slope (~30°) that was located directly above the rupture surface of the responsible fault and then traveled ~2 km after flowing down the axes of two gently slop...

In this paper, a transient rainfall infiltration and grid-based regional slope-stability model (TRIGRS) was implemented in a case study of Yan'an City, Northwest China. In this area, widespread shallow landslides were triggered by the 12th July 2013 exceptional rainstorm event. A high-resolution DEM, soil parameters from in-situ and laboratory meas...

The deep-seated reservoir ancient landslide often shows intermittent reactivation which corresponds to seasonal rainfall and periodic reservoir water level fluctuation. In this kind of reactivation, sliding and sliding dormancy occur alternately. This means that the sliding zone soils may experience shearing at different shear rates and consolidati...

On 11 January 2013, a catastrophic landslide of ∼0.2 million m3 due to a prolonged low-intensity rainfall occurred in Zhenxiong, Yunnan, southwestern China. This landslide destroyed the village of Zhaojiagou and killed 46 people in the distal part of its path. The displaced landslide material traveled a horizontal distance of ∼800 m with a vertical...

The frictional behavior of granular materials plays important roles in the movement of geo-materials in landslides and earthquake faults, and of industrial materials; many studies have been put forward to better understand the frictional behavior of granular materials under differing conditions. In this paper we report on laboratory experiments des...

A displacement-based seismic discontinuous deformation analysis (DDA) considers the influence of an earthquake by applying a time-dependent displacement constraint to simulate time-dependent ground movement of the base rock. However, unexpected variations of the base block stress and the block area in a seismic DDA may affect the block contacts wit...

It is widely accepted that the majority of post-wildfire debris flows are triggered by surface runoff and sediment bulking in response to short duration, high intensity rainfall events. Infiltration-triggered debris flows that result from discrete bodies of soil dislodging from the slope are less frequent, and tend to appear after longer periods of...

The natural blockage of river channels by landslide debris gives rise to a range of potentially adverse processes including complete or partial damming, backwater inundation and sedimentation, catastrophic outbursts of impounded lake waters, and downstream river aggradation following dam failure. Most reports portray landslide dams as short-lived a...

During the 2004 Mid-Niigata Prefecture earthquake, thousands of landslides were triggered, among them two large scale landslides (Higashi-Takezawa and Terano landslides) occurred within past landslide masses and dammed the river at the toe of the landslides. To understand the internal structure of the landslide dam and then provide more reliable pa...

The frequency of huge debris flows greatly increased in the epicenter area of the Wenchuan earthquake. Field investigation revealed that runoff during rainstorm played a major role in generating debris flows on the loose deposits, left by coseismic debris avalanches. However, the mechanisms of these runoff-generated debris flows are not well unders...

This manuscript provides insight into a new approach to chemically induce water repellency in soils with silanes, in particular dimethyldichlorosilane (DMDCS). Silanes create a water repellent surface on any silica-based material resulting in a near permanent effect. Wettability measurements were conducted with the Sessile Droplet Method via contac...