Muhsiung Chang

National Yunlin University of Science and Technology · Department of Civil and Construction Engineering

Liquefaction-induced flowslides would cause significant damages and casualties as the case of 2018.9.28 incidences of Palu, Sulawesi, Indonesia, where the flowslides occurred immediately after a severe earthquake and led to an extremely-long distance of sliding on mild sloping ground. The conditions that would favour soil liquefaction and the assoc...

Soil liquefaction is the phenomenon associated with strong earthquake and has caused severe damage to structures. The liquefaction remains a major concern for geotechnical engineers, as the shear strength of saturated loose sands decreases drastically with the generation of positive pore pressures under seismic excitation resulting the breakage of...

A huge flow slide induced by liquefaction occurred in several areas of Palu city, Indonesia, due to the Mw 7.5 Palu-Donggala earthquake on Friday, 28 Sept 2018. Many villages, including Balaroa, Petobo, Jono Ogee, and South Sibalaya, had experienced catastrophic destructions due to flow slide liquefaction. This study focused on the flow slide area...

On November 27, 2017, a debris flow occurred in the Brungkah river, Pacitan, Indonesia, caused by extreme rainfall. Debris flow passed through and transported the sediment materials along the Brungkah river and stopped at the river confluence with the Grindulu river. The debris flow destroyed the main village access road to the Tukul dam and clogge...

A huge flow slide induced by liquefaction occurred in several areas of Palu city, Indonesia, due to the Mw 7.5 Palu-Donggala earthquake on Friday, 28 Sept 2018. Many villages, including Balaroa, Petobo, Jono Ogee, and South Sibalaya, had experienced catastrophic destructions due to flow slide liquefaction. This study focused on the flow slide area...

Soil liquefaction and its associated ground failures, pose a significant threat, causing damage to engineering structures during earthquakes, and one of the most effective methods used to mitigate liquefaction in liquefied soil is micro-pile (MP) method. Therefore, this study aims to examine the current state of MP method as liquefaction countermea...

Soil liquefaction is an important issue in the field of environmental geotechnics where level ground loses its bearing, causing failure or settlement of structures. In cases of river bank or mildly sloping ground, however, liquefaction-induced lateral spreading or flowsliding would be more devastating, where structures on the ground would be ripped...

A magnitude (Mw) 7.5 Palu-Donggala earthquake struck Palu, Indonesia on Friday, 28 September 2018 at 18:02:44 Central Indonesia Time (GMT+8). The earthquake resulted in tsunami and flowslide liquefaction. Balaroa, Petobo, Jono Oge and South Sibalaya were affected areas of flowslide liquefaction. Area of Petobo flowslide liquefaction had the largest...

This paper presents the results of the subsurface investigation and liquefaction assessment of the Petobo flowslide, induced by soil liquefaction during the Mw 7.5 Palu–Donggala earthquake of Indonesia on 28 September 2018. The investigations, including drilling, standard penetration tests, electrical resistivity imaging survey, dynamic probing, gr...

A huge flowslide due to liquefaction occurred at Petobo on September 28, 2018. Many building structures were collapsed, tilted, buried, or moved away up to a distance of 800 m or more. Flowslide occurred at slopes of around 3° and the affected area was approximately 1.64 km2. Magnitude and intensity of earthquake shaking, soil and groundwater condi...

A series of large-scale flowslides triggered by soil liquefaction due to Palu-Donggala earthquake on September 28, 2018, has struck the urban area of Palu City, Indonesia. In contrast to others flowslides, Petobo flowslide was the most damaging for massive size, huge fatalities, and serious destruction of properties. To obtain the soil profiles and...

Soil liquefaction and associated ground failures are one of the most destructive natural hazards that cause damages to engineering structures during the earthquake. This paper presents an alternative to mitigate the risk of liquefaction and associated ground deformation by stone column (SC). In this study, a three-dimensional finite-element (FE) si...

Taiwan High Speed Rail (THSR) is currently the fastest land transportation facility in Taiwan, with an operating speed of up to 300 km/h. In order to maintain safety and high speed of the trains, the levelness of THSR tracks becomes a very important consideration. However, differential settlements in THSR piers caused by subsidence of the ground in...

Buckling instability has been identified as a possible mechanism of pile failure in liquefiable ground and this failure mechanism is not explicitly mentioned in most of the design codes. Pile buckling would be affected, however, by various factors including liquefaction zone of foundations soils, axial loads of piles, geometry as well as arrangemen...

The 2018.9.28 Indonesia Palu-Donggala Earthquake had caused substantial soil liquefaction and induced significant flow slides in the Petobo area of Palu, Indonesia. In an article published previously in Sino-Geotechnics, the authors presented the observations from an onsite reconnaissance and proposed a morphological zonation for the sliding mass....

Soil liquefaction can be attributed to the combining effect of three main causes which are cohesionless soil, high pore water pressure, and earthquake motion. As a numerical analysis software often being used in geotechnical field, Plaxis2D is capable of solving soil liquefaction problems. During Plaxis2D simulation for liquefaction, ground water t...

2018.9.28印尼Palu-Donggala地震造成Petobo地區土壤液化引致的長距離地盤滑動現象，本研究詳述作者群於該地區所進行之現地調查，藉由現地踏勘、地質鑽孔、地電阻探測、GCO貫入試驗、現地透水試驗、地下水位觀測及土壤室內試驗等劃分地表特徵、土壤性質及地層分佈，使有助於後續滑動原因與機制之探討。本研究現地踏勘結果發現，Petobo 地區地表特徵主要劃分為四種型態: (1)地表錯動(Ground Slip)、(2)液化側潰(Liquefaction Spreading)、(3)液化流動(Liquefaction Flow)、(4)土石漫流(Debris Flood)。由現場地電阻探測及地質鑽探結果推測，液化滑動層面約略位於地表下10公尺處。地質鑽探結果亦顯示，於滑動區域上中游之地...

Liquefaction is a condition of soil mass that undergoes continuous deformation at low residual strength because the pore water pressure increases, causing the effective stress to decrease and under certain circumstances, it reaches zero. The natural phenomenon of liquefaction can lead to structural damage of a building in an earthquake-prone area....

Soil liquefaction and associated ground failures are one of the most destructive natural hazards that cause damages to engineering structures during the earthquake. This paper presents an alternative to mitigate the risk of liquefaction and associated ground deformation by stone column (SC). In this study, a three-dimensional finite-element (FE) si...

In 2018, a strong earthquake with a moment magnitude of 7.5 struck Indonesia's Sulawesi Island. Due to considerable ground shaking, liquefaction-induced flow slides with travel distances ranging from a few hundred meters to more than one kilometer were observed on the surface. Numerical simulations of the liquefaction flow slide in Petobo area in t...

This paper discusses unexpected influences of the miss-assignment of groundwater table in the analysis of soil lique-faction. In viewing that the groundwater table (0) during subsurface exploration for evaluating cyclic resistance ratio () of soils is sometimes mistakenly assumed the same as the groundwater table () for computing cyclic stress rati...

This paper discussed an alternative to compute and analyze the buckling instability of piles in a liquefiable ground during seismic loading. A key aspect of the study is a comparison of different approaches on buckling assessment of piles using deterministic and numerical method. The study discusses the assessment of buckling instability of piles d...

This paper continues the discussion of a companion paper (Part-I) on the liquefaction-induced long-distance sliding in the Petobo area during the 2018.9.28 Palu-Donggala Indonesian earthquake. This paper focuses on the witness accounts of the observations made during the earthquake shaking and sliding, as well as the onsite mapping and the characte...

On 27 November 2017, a debris flow took place in Brungkah river, Pacitan, Indonesia, which caused by an extreme rainfall. Debris flow passed through and transported the sediment materials along the Brungkah river and stopped at the river confluence with the Grindulu river. The debris flow destroyed the main village access road to Tukul dam and clog...

A huge flowslide induced by liquefaction occurred in several areas of Palu city, Indonesia as a result of Mw 7.5 Palu-Donggala earthquake on Friday, 28 September 2018. Many villages including Balaroa, Petobo, Jono Ogee and South Sibalaya had experienced catastrophic destructions due to flowslide liquefaction. This study focused on flowslide area of...

2018年 9月 28日於印尼蘇拉維西島(Sulawesi)發生規模Mw7.5大地震，除造成該島首府帕盧市(Palu)所在 峽灣之海嘯 外，也引發 其內陸地區 多處大規模 的土壤液化滑動。本文說明其中 最 主要的土壤液化滑動事件，發生在帕盧市東南方的Petobo地區。在此地震造成的液化滑動中，Petobo之滑動面積排第二(1.64 Km 2)、僅次於Jono Oge，然而其滑動距離遠(>800m)、災損最為嚴重(估計>3300棟房屋毀損及~2000人死亡)。這些滑動區存有若干共同點，包括：原地表平均坡度平緩(<3º或 <5%)且滑動區上緣緊鄰灌溉渠道等。至今，造成長距離滑動原因仍諸多揣測、尚無結論；本文作者群到現地進行踏勘、鑽探與試驗，祈能對於滑動原因與機制有所釐清。以下內容說明本研究初步成...

Choshui River alluvial fan-delta (CRAFD) has been and still is the single-largest subsiding area in Taiwan. Some key infrastructures, including Taiwan High Speed Rail (THSR) and Expressway 78 (Expwy78) that come across this area, are suffering serious problems by the subsidence. Due to complexity of the issue, causes of the subsidence and their inf...

The Palu-Donggala earthquake struck Palu city of Sulawesi island, Indonesia, on 28 September 2018. A large-scale liquefaction phenomena occurred in some areas which caused massive fatalities and destructions. The most severe liquefaction incident during the earthquake followed by flowslides occurred in Petobo district of the city. The affected area...

To clarify the influence of boundary insulation on the development of frozen soils, seven artificial ground freezing (AGF) models of Ottawa sand were performed with different thermal impedance Z-values of the boundary insulation system. Results of testing show that the greater the Z-values, the larger the frozen soil areas for a given time of freez...

This paper discusses the issue and potential influences of miss-assignment of groundwater table in the analysis of soil liquefaction. In viewing that the groundwater table (GWT0) during subsurface exploration or testing for evaluating cyclic resistance ratio (CRR) of soils is sometimes mistakenly assumed the same as the groundwater table (GWT) for...

Liquefaction-induced flowslides occurred in several places of Palu City, in the Central Sulawesi of Indonesia, due to Palu-Donggala earthquake with a magnitude (Mw) 7.5 on September 28, 2018. One of the landslides was in Petobo Village, which is close to Mutiara SIS Al-Jufrie Airport of the city. Petobo landslide, with an area of approximately 1.64...

This paper discusses the failure problems of piles due to seismic shaking and soil liquefaction. As relatively less-mentioned, the assessment procedure for buckling of piles in liquefiable ground is also introduced. During earthquakes, saturated sandy soils are prone to liquefaction. In the case of sloping ground or waterfront areas, lateral spread...

This paper discusses the behavior and contributing factors of land subsidence in the intersection area of Expressway (Expwy) 78 and Taiwan High Speed Rail (THSR), located on Choshui River alluvial fan-delta (CRAFD) to the midwest of Taiwan. Since the CRAFD has been suffering a long-time problem of land subsidence, the transportation safety of THSR...

This paper discusses an alternative to compute and analyze pile buckling in liquefiable ground dur-ing seismic shaking. This study is undertaken based on three-dimensional finite element (FE) simulations using OpenSeesPL. To explore the effect of shaking, soil and pile behaviors are observed at different axial loading conditions. The results reveal...

A severe earthquake would normally contribute to damages to superstructures and other infrastructures and would often result in losses of lives. As the earthquake loading cannot be precisely estimated or prevented, the professional engineers generally require understanding to the safe design of earthquake-resistance structures. The pile foundation...

This paper discusses a case study on the assessment of buckling stability of piles due to liquefaction of foundation soils for a coal-fired power station (CFPS) in Indonesia. As the rapid growth in the economy sector, the demand for electricity is increasing and a CFPS is planned and constructed in Central Java. During the planning stage, the risk...

This paper discusses results of a long-term onsite monitoring on ground subsidence and soil compressibility at the intersection of Expressway (Expwy) 78 and the High-Speed Rail of Taiwan (THSR). The intersection area is located on the Chuoswei River Alluvial Fan-Delta (CRAFD), the largest and thickest alluvial deposit to the mid-west of the island....

Indonesia is facing rapid growth in economy and results in increasing demand for electricity. To supply sufficient electricity, Indonesian Government has constructed a coal-fired power station (CFPS) Tanjung Jati Units 5 & 6 with a capacity of 2 x 1000 MW. The site of this study is in Tubanan Village, Kembang District, Jepara Regency, Central Java...

Plane strain approach is commonly adopted in engineering practices today for analysis of wall deflections during underground excavations owing to its convenience and lower cost. For small-to-medium sized excavations, however, a three-dimensional approach would be more appropriate for the wall deflection because of the influence of corner effect by...

In this study, the effect of heat-carrying capacity of brine on the growth of frozen soil is examined through an artificial ground freezing model testing, with or without a seepage flow condition. By installing heat flux plates in the model, we can measure the heat flow in soil during the freezing process. The model testing is conducted with differ...

This article addresses the issue and potential influences of misassignment of groundwater table in the analysis of soil liquefaction. The groundwater table(GWT0)during subsurface exploration for evaluation of cyclic resistance ratio (CRR) is often mistakenly assumed to be the same as the groundwater table (GWT) for computing cyclic stress ratio (CS...

Chuoswei River Alluvial Fan-Delta (CRAFD) is the largest alluvial deposit located in the mid-west of Taiwan. The fan-delta, formed by Chuoswei River, has been influenced by the ocean during glacial retreats and advances within recent 200 thousand years. As a result, the CRAFD consists of alternating layers of alluvial and marine deposits, where all...

Artificial ground freezing (AGF) technique has been considered as a safe, economical and environment-friendly method for the excavation in underground construction engineering. In the case of flowing groundwater, the seepage flow carrying with heat would be destructive to the growth of frozen front. However, the critical velocity of groundwater flo...

This paper discusses improvements of compressibility, permeability, static and liquefaction strengths of in-situ soils by grouting. Both field testing and laboratory evaluation of the on-site samples were conducted. The improvement of soils was influenced by two main factors, i.e., the grout materials and the injection mechanisms introduced by the...

Generally, grout extent and ground deformation are of great concern in soil grouting practice. In this paper, the ground behaviour, injection mechanism and grout distribution relating to field grouting in soils are discussed. It is found that the mechanisms of injection comply with generally accepted groutability requirements based on particle size...

Hydraulic fracturing is a potential cause of leakage of earth dams or loss of fluid in drilling and field permeability testing. The effect of hydraulic fracturing on soil grouting is also a major concern. Although hydraulic fracturing has been adopted for decades by the petroleum industry for oil recovery in rock formations, studies on fracturing i...

Mt. Ali Road is a main scenic route to Alishan National Scenic Area and Yushan National Park in the middle of Taiwan. At Mileage 39Km, the downslope side of the road consists of a 200m deep 60° angle bare cliff with a creek passing around the slope’s toe. Despite complex geologic conditions, the underlying slope materials appeared competent for abo...

Preloaded tip grouting has been proposed in Taiwan to enhance the drilled shaft bearing capacity that would be discounted due to drilling and installation. The technique takes the advantages of reverse shears along the shaft and compactions of bearing stratum underneath the tip as a result of the grouting Nonetheless, the mechanism and causes that...

Artificial ground freezing (AGF) technique has been commonly adopted in under-ground excavation for key components of engineering projects that require special cares in accuracy and safety. The success of AGF technique, however, will depend on several factors, in which the groundwater flow appears to be a major one that would change the temperature...

Artificial ground freezing (AGF) technique has been commonly adopted in underground excavation for key components of engineering projects that require special cares in accuracy and safety. The success of AGF technique, however, will depend on several factors, in which the groundwater flow appears to be a major one that would change the temperature...

Since the bearing capacity of drilled-shaft is greatly affected by the slime around pile tip, the tip grouting is often used by the industries. However, the whole process of this technique needs to be verified. The study herein provides the numerical results using discrete element program PFC 2D to simulate the tip grouting and finite element compu...

Artificial ground freezing (AGF) technique has gradually been considered as a safe and environmental-friendly method for underground construction of key projects in the urban area in Taiwan. Due to several uncertainties in the application of the method, a field AGF testing was therefore set up and conducted in the campus of National Yunlin Universi...

Base grouting has been adopted to solidify the loosen material and remained slime at pile tip due to the drilling process. Theoretically, base grouting would enhance the bearing capacity of pile by the injected pressure that causes pre-stressing of the shaft resistance and pre-loading of the end bearing of the pile. To verify the improvement of bas...

Synopsis: Artificial ground freezing (AGF) technique has been considered as a safe, economical and environment-friendly method for the excavation in the urban area. The effectiveness of the technique, however, is closely related to the formation of a continuous frozen zone in the excavation area. In the case of flowing groundwater, the seepage carr...

Synopsis: This paper discusses the mechanism of tip grouting through physical and numerical studies. Physical testing provides observations of injection pressure, injection rate, pile uplift, and the formation of grouted mass during the grouting process. Numerical simulations adopt a particle flow code to verify the observations in the physical mod...

The study herein conducts a series of plane strain compression tests to obtain macro-parameters (i.e., friction angle φ') of two test sands. The macro-parameters are then employed to calibrate the micro-parameters of the sands, such as friction coefficient (fric), normal and tangent stiffnesses of particle contacts (Kn and Ks), etc., which are requ...

The paper discusses the results of liquefaction potential and post-liquefaction settlement evaluations of the Chuoshui River Alluvial Fan (CRAF), the largest fan-delta in Taiwan. In 1999, the Chi-chi Earthquake (Mw = 7.6) caused significant liquefaction damage in several locations in the CRAF. The paper reviews the hydrological and geological setti...

A widely used method for evaluating the damage and possibility of soil liquefaction, called Liquefaction Potential Index (P L), was proposed by Iwasaki in 1982. The values of 5 and 15 are the critical boundaries of P L to describe the damage which soil liquefaction will occur. The method is also adopted in the building design codes in Taiwan. The i...

The study herein discusses the injection mechanism of drilled shaft base grouting through model testing and numerical simulations. A 2D scaled model was set up and results indicated some injections with hydro-fracturing mechanism, while more were with compaction and permeation phenomena. For soils with lower density, the injection tended to be more...

Since the bearing capacity of bored piles was greatly affected by the slime around pile tip, the tip grouting was used to solve the problem. However, the whole process of this technique needs to be verified. The study herein provides the numerical results using computer software GeoStudio 2004 to simulate the tip grouting and pile loading test acco...

基樁已逐漸用於邊坡整治工程，作為阻止或減緩邊坡滑動的重要方法之一。然而，邊坡抗滑基樁與地層間之互制行為極為複雜，難以既有理論準確分析，因此基樁設計常無法精確掌握，而造成過保守（浪費）甚或不保守（不安全）之情況。本文以台18 線阿里山公路五彎仔地滑區第四至第六回彎之抗滑排樁為研究對象，以自行設計之土壓片、進行邊坡抗滑樁側土壓力之現場監測，並探討抗滑樁與其週遭土壤在邊坡中之受力與變形行為。依據現地監測結果顯示（e.g.，土壓力、地層位移、地下水位、降雨量等），降雨為邊坡滑動之主要促發因素，當邊坡滑動時將造成抗滑樁身側土壓力之改變。監測結果亦發現，抗滑樁埋置深度不同（i.e., 樁長是否深入穩定地層或僅「浮」於滑動塊體中）將影響樁體移動以及樁身側壓力分佈。除邊坡滑動影響外，地錨預力之施拉也將造成樁...

Soil grouting is generally adopted to enhance engineering properties of soil deposits by introducing cohesive agents into the ground. The effectiveness of the technique, however, is influenced by various factors, and relies upon a substantial portion of on-site experience and engineering judgment. Major uncertainties in grouting appear to be the ac...

本文論及之證明試驗係指現場證明試驗，地錨即使未拉到破壞，仍可由潛變係數的變化，預 估該地錨的潛變極限荷重；適用性試驗的目的則為確認施工後地錨能否完全符合設計要求，以上二試驗並藉由實際案例說明其分析過程。從案例（1）與案例（2）比較得知潛變係數值偏低時，求得之潛變極限荷重相對提高。案例（1）於荷重～變位曲線開始急遽增加之折點求得地錨極限荷重（Tu）。案例（2）由於荷重已臨界最大試驗荷重仍未拉脫，故未持續施拉，因此經由試驗求取錨碇地層之摩擦應力（τa），並反推地錨之極限荷重。案例（3）經由適用性試驗求得摩擦損失荷重（Tf）及鋼腱滑動損失荷重（Ts）致使原擬鎖定荷重（To）略顯不足，建議應向上略作調整。案例（1）證明試驗求得之地錨極限荷重可以反推地層極限摩擦應力；然而本文研判應與設計估算值差異大，...

Taiwan is located in the conjunction area between Eurasia Plate and Philippine Sea Plate. As a result, the geology condition of the island is complex and the earthquake activity is frequent. On September 21, 1999, a severe earthquake (M L = 7.3) hit Chi-chi Town and resulted in significant damages and casualties in the mid-west plain of Taiwan. The...

The creep deformation of slopes in Woo-wan-chai landslide area has been a serious problem for District V, Directorate General of Highways, Taiwan, in maintenance of Province Road 18 since opening. With a 3-Km long section being laid across the area, the road is a main access to Alishan National Scenic Area and Yushan National Park in Taiwan. To clo...

Province Road 18, or so-called Alishan Road, has been experienced problems of landslip or road subsidence as a result of typhoons or heavy rainfalls since the road construction. On June 26, 2003, a significant landslide occurred at the mileage of 31.5 Km along the road caused an interruption of the road for about 3 months. The government agency-in-...

Inclinometer has been frequently used as a direct and effective means for deformation measurement of the ground and structures. Results of inclinometer measurement, however, are normally limited to the lateral displacement-depth profile. To have a better understanding, a laboratory simulation on the incli-nometer measurement was therefore undertake...

台18 線為通往阿里山國家風景區與玉山國家公園之重要觀光道路。該公路 39K (即舊里程 25K) 附近於民國 90 年 9 月納莉颱風過境期間，造成該段公路與邊坡嚴重龜裂與變形。公路總局第五區 養護工程處(五工處)利用部分懸臂路面之中空式擋土結構、並配合地錨與微型樁之設置，以修 復交通。民國 94 年 8 月 30 日泰利颱風過境台灣，帶來豐沛雨量，該路段上下邊坡遭受嚴重沖蝕 與滑移，原修復之路面路基於同年 9 月 1 日跌落溪谷，造成公路完全中斷。五工處隨即進行緊急 搶修臨時便道、恢復雙向交通。然而一個月後，龍王颱風接續侵襲，臨時便道路基再次掏空，路 寬驟減為 3m，嚴重影響行車安全。五工處乃進行該路段之災害修復工作，內容主要包括上邊坡面 之裂隙填補、植生、與排水等項目。目前修復工程已大...