作者

陳堯中

摘要

百年大震不但造成人命財產的鉅大損失，也震出許多工程上的問題，可說對國內工程之設計施工品質作了一次總體檢。經由媒體的報導，倒塌的房屋、樑柱中的沙拉油桶、不足的箍筋、劣質的混凝土、土壤的液化等等，皆一一呈現國人眼前，造成工程界極負面之形象。在痛定思痛之餘，值此世紀交替之千禧年開端，如何把握機會深刻檢討，以奠立下一個百年之基，實是當務之急。地工技術研究發展基金會秉持提升國內地工技術水準之理念，於88年11月在北中南各舉辦了一場名為「集集大震對大地工程技術之考驗」的座談會，獲得各界熱烈迴響。為使本次地震的許多珍貴資料得以整理保存，供各界參考研究，特編輯本期專刊，由於時間倉促，許多詳細的調查研究工作尚未完成，故專輯內容主要為相關地工破壞案例的紀錄與初步分析探討，至於詳細的破壞原因分析、設計分析方法的改進、法規的檢討等，則待日後另以專刊方式向各界作完整報導。
本期專輯內容大致上可分為山崩、土壤液化、基礎與擋土牆之破壞與修護、壩工與隧道、斷層活動與地工設計考量等。在山崩方面，洪如江教授等之「天塹可以飛渡、崩山足以斷流」一文，延續其一貫風格，以精彩的照片詳細報導草嶺大崩山的現場災害情況，為讀者作了一趟紙上導覽。蔡光榮教授等之「921集集大地震誘發大山崩與形成堰塞湖災害初步調查」一文，引用國外文獻資料，說明堰塞湖形成後之穩定性問題，對思考草嶺堰塞湖之存廢提供了有用的參考資料。
本次地震在中部地區造成廣泛的土壤液化問題，引起國人及地工界的高度重視，因此本期專輯收錄四篇有關土壤液化的文章。褚炳麟教授等之「921地震霧峰、太平地區液化及下陷調查分析」一文，針對霧峰鄉及太平市土壤液化之範圍與相關災情作詳細介紹及初步分析。蘇鼎鈞等之「員林鎮土壤液化現狀調查成果及初步研判」一文，為員林鎮土壤液化災害之現地踏勘調查結果。余明山等之「中部海埔新生地液化災情勘察」一文，整理三處海埔新生地之液化災害情形，並對災害原因進行初步探討。黃俊鴻教授等之「集集地震土壤液化之調查與分析」一文，整理地動、鑽探與液化調查資料，提出初步研究分析結果。蘇吉立等之「921地震後台中港北碼頭災象調查分析」一文，針對台中港受震之災損情況詳細說明其調查結果。
在基礎與擋土牆方面，廖洪鈞教授等之「集集大地震基礎震災情況及復建對策」一文，說明基礎震災調查結果，並就部分基礎破壞形式提出重建對策，對液化地區之建築物基礎建議以灌漿固化土壤或基礎托底方式進行修復。方永壽教授等之「集集大地震造成之擋土牆結構物破壞」一文，針對集集地震所造成之各種型式擋土牆破壞案例，說明其破壞情形及可能之破壞機制。
在壩工與隧道方面，張吉佐與張森源之「壩工與隧道之初步檢查」一文，說明中部地區重要壩工及隧道在集集地震中0之受震情形，並初步評論其耐震設計之適當性。陳錦清與張森源之「就集集地震之土石壩行為探討國內土石壩安全評估方法之妥當性」一文，以國內外土石壩受地震侵襲之案例資料及國內主要大壩地震安全評估之結果，檢討國內土石壩之抗震能力及目前採用地震安全評估方法之可靠性。
921集集大地震誠然造成嚴重之災害，但也震醒各界沉睡之良心，災變後全國同胞上下一心，不分彼此全力投入救災工作，那種無私無我、熱心奉獻的精神，實在令人感動，在此呼籲地工界朋友能持續保有當時的愛心與慈悲心，不斷的關懷別人並努力將自己工作做好，讓大家都能住的安心。希望藉由本次專輯的出刊，能將珍貴的資料加以紀錄保存，對後續的研究分析工作有所助益。

作者

羅俊雄

摘要

台灣在民國88年9月21日凌晨01時47分12.6秒(格林威治時間20日17時47分12.6秒)於南投縣集集附近發生強烈地震。震央在北緯23.87度東徑120.75度，即位於日月潭西方12.5公里處，震源深度約7至10公里，地震規模達ML=7.3或Mn=7.6。此地震為車籠埔斷層之錯動而引發之內陸形淺層地震，其錯動長度全長約105公里。在斷層線上及其附近之鄉鎮其結構物幾乎遭受嚴重破壞，同時因地震引致大地相關之災害其，受災面積極廣，包含著土壤液化災害、地層下陷災害、基礎破壞及坡地破壞等。其中尤其是靠近水系沖積之砂質土壤其液化現象顯著，且山脈經水流切割、地形上坡度較陡且地震引致地表加速度較高處，坡地破壞亦明顯。在台灣地震為常發生之天然災害之一，再加上經濟之蓬勃發展，人為建設與天然環境之衝突勢必增加天然災害之危險度，如何減緩天然災害所造成之損失為工程師在設計及建造任何土木工程結構物所需要考慮的。
921地震發生後國家地震工程研究中心得到各大專院校及專業技師、各顧問公司之協助，組成九組災害調查小組(含斷層與地質組、強地動組、大地工程組、建物組、橋樑組、維生線組、水利設施組、工業設施組及社會經濟組)進行災後勘災及收集災情，以記錄下未來研究地震工程相關之資訊，在此致最高之謝意。
由此次地震所造成在大地工程之災害，經初步研究有下列數項問題是值得從業人員、研究機構人員及政府單位所須檢討及重視：
1. 各類大地工程相關之資料庫，如土壤地質、坡地條件資料等應儘速建立，據此資訊可作為進行大地工程災害之風險評估及損失評估。
2. 全國液化潛勢及坡地災害潛勢圖之製作，並提供民眾瞭解液化及坡地破壞等大地工程災害之風險性。
3. 大地工程之設計規範重新檢討，並納入此次大地災害之教訓，提高結構物之安全度以減少大地工程災害。
4.提出山崩土石堰塞湖下游緊急應變措施及解決方法。
5.檢討現存公路邊坡崩壞之機制並標示高危害度之區段及建設防治措施。
此次地震雖然對國家及人民造成極大之損失，站在地震工程及大地工程專業之從業人員之立場，若能從此次慘痛之經驗中學習到地震造成之損壞原因，進而改善及提高地震防災能力，未嘗不是一件正面的學習，在此與大家共勉之，並期待未來經此經驗後在地震引致大地工程災害方面能減到最低，共同在此塊土地上創造一個低災害的樂園。

英文篇名

A FLYING MOUNTAIN AND DAM-UP LAKE (TSAO-LING ROCKSLIDES)

作者

洪如江、李錫堤、林美聆、林銘郎、鄭富書、陳正興

關鍵字

草嶺、順向坡滑動、堰塞湖、地震

摘要

草嶺順向坡滑動發生於1862年（史前地震），民國30年（地震），民國31年（豪雨），民國68年（豪雨）與民國88年（地震）。在1862年、民國30-31年、民國68年與民國88年等事件中，清水溪皆積水成潭。由880921地震所造成之新草嶺潭正由經濟部水利處監測中。921地震之時，草嶺大崩山區發生順向坡（傾斜角約度14）滑動。坍方体積約有1億2千萬立方公尺。其中，約2千5百萬立方公尺之土石散落在長達5公里的清水溪中。大部分土石（約1億立方公尺），連同原住草嶺春秋斷崖上方之崛的14戶36人，飛越清水溪河谷而降落於倒交山上，簡家29人遇難，7人互救生還。房屋碎片與一部箱型車（寶馬747）尚可見於本文照片一之中。簡英造先生利用寶馬747車中之無線電對講機向外求救。本文也提供巨大滑動体底部存在氣墊之證據。

英文摘要

Tsao-Ling rockslides, involving mass movement of more than hundred million cubic meters, happened in the foothills region of Taiwan in 1862(pre-historical，earthquake), 1941(rain), 1942(rain), 1979(rain), and 1999（earthquake，M 7.3）. The Ching-Shui river was dammed in the 1862, 1941-1942, 1979, and 1999 events. Overtopping and breakaway of landslide dams were observed and recorded in 1951 and in 1979. The outcome of the dam-up lake of the 1999 event is being monitored. During the September 21st 1999 earthquake event, a rock mass of about 120-million cubic meters slid down the Tsao-Ling dip slope having a dip angle of 14 degree or so. Only 20%（about 25-million cubic meters）of the sliding mass dropped into the valley of the Ching-Shui river. Most of the sliding ma+H45ved behind the crest （called Crest Forever）of the dip-slope, flew over the Ching-Shui river and made moderate to soft landing on the remaining part of the old landslide dam. Seven of them were alive. 29 of them lost their lives. Some of the debris of their houses and a van （called Bou-Ma 747）can be seen in the center of Photography No.1 of this paper. They used the wireless telephone in the van to request help from outside Tsao-Ling village. Evidence of an air cushion under the sliding mass is given.

英文篇名

LIQUEFACTION AND SETTLEMENT IN WUFENG AND TAIPING COUNTIES DURING CHI-CHI EARTHQUAKE

作者

褚炳麟、張益銘、陳冠閔、徐松圻、張錦銘

關鍵字

液化、地震、下陷、側向擴展

摘要

921集集大地震在台中縣內除了造成台中港數個沉箱碼頭因液化而導致地層下陷與滑移外，靠近沿海之清水鎮及大肚鄉亦有液化噴砂災情，且由於此次地震之震央位於台灣中部地區加上強度之大及延時極長，致使連靠近西部麓山帶之霧峰鄉及太平市也發生因液化而導致嚴重災害。本文針對霧峰鄉及太平市液化之範圍及相關災情作一詳細介紹及初步分析。液化除了冒水噴砂外，尚有地層及房屋下陷、傾斜、水平位移，以及側向擴展等現象，主要液化噴砂位置則大多位於河道之兩側，且在河流彎道之沉積側居多。而可能發生液化之深度及及噴砂性質，可由所蒐集到之鑽孔資料及粒徑分析結果得到間接證實。

英文摘要

Soil liquefaction due to Chi-Chi earthquake was found at Taichung harbor and several counties along the coast in Taichung. As a result of this strong earthquake occurred at the middle of Taiwan and the duration was long enough, the counties, Wufeng and Taiping, next to the western mountain areas also had serious damages due to soil liquefaction. Locations of soil liquefaction and corresponding damages in these two counties are investigated and described in this paper. There are several phenomena associated with soil liquefaction can be observed, they are sand blows, settlement and inclination of ground or buildings, lateral movement and spreading, and flow failure. The major places of sand blows are found to locate close to or beside the rivers, especially the sedimentation side of a river. The possible depths of liquefaction and soil properties are analyzed using collected boring log data and results of grain size distribution of the sand blow.

英文篇名

FIELD RECONNAISSANCE AND PRELIMINARY ASSESSMENT OF LIQUEFACTION IN YUAN-LIN AREA

作者

蘇鼎鈞、姜凱文、林向榮、王復國、段紹緯

關鍵字

液化

摘要

民國88年9月21日淩晨1：47分發生的集集大地震，地震規模高達7.3，造成2300多人因而喪生，災情極為慘重。其中彰化縣的員林地區發生土壤液化現象，道路及建築物沉陷傾斜情形嚴重。本文為彰化縣員林鎮現地踏勘及訪談里村長和居民之土壤液化現狀調查成果，除將地表有明顯液化表徵及道路建物有明顯因土壤液化發生沉陷傾斜者予以拍照記錄外，並依現狀調查結果，將其位置或範圍標示於圖上。惟若地表如果沒有明顯表徵，並不表示深層土壤沒有液化情形之發生，實際土壤發生液化可能分佈範圍，則仍宜經由現場鑽探、試驗，以及液化評估分析比對後，方可獲得較可靠的結果。本文中有關土壤液化災情之記錄，將供後續進一步利用地質調查結果，進行液化評估及分析比對時之參考資料，以建立本地區之液化潛能分區。

英文摘要

The Chichi earthquake, with a magnitude of (Ritcher Scale) 7.3, struck central Taiwan in the early morning of 21 September, 1999 at 1:47 am, and caused wide damage not only in the central region but as far as the whole Taiwan island. More than 2,300 people died in this big disaster. The Yuan-Lin area in ChangHua County suffered extensive damage including settlement and inclination of buildings and roads due to liquefaction. This article presents the results of field reconnaissance of the liquefaction affliction. Several locations, including obvious phenomenon of sand boils on the ground and inclination or settlement of the roads and buildings due to liquefaction were photographed and marked on the map. Nonetheless, without obvious sand boils on the ground do not mean that there is no liquefaction happened underground. In order to determine possible areas where liquefaction could take place, extensive evaluation must be undertaken. The records of liquefaction affliction presented in this article will provide correlative information for further assessment and analyses of the liquefaction problem, and thus to assist in determining liquefaction potential in the entire Yuan-Lin area.

英文篇名

LIQUEFACTION INDUCED BY CHI-CHI EARTHQUAKE ON RECLAIMED LAND IN CENTRAL TAIWAN

作者

余明山、鍾毓東、謝百鍾

關鍵字

集集地震、水力抽砂回填、海埔新生地、液化

摘要

集集地震為中部地區百年來罕見之大地震，不僅造成中部地區地層發生大變動，更使中部地區出現許多難得一見之土壤液化現象。本文主要整理中部三處海埔新生地－麥寮石化工業區、彰化濱海工業區及台中港於本次大地震洗禮下之液化災損情形，並對災損原因進行初步探討，以提供日後海埔地開發之借鏡。

英文摘要

The Chi-Chi Earthquake, which is the most damaging one on the Western Island of Taiwan in past hundred years, not only caused disastrous torrential changes but also induced soil liquefaction in Central Taiwan, which in itself is also very scarce. This article serves as a liquefaction disaster report on the three reclaimed lands, My-Lio Industrial Park, Chun-Pin Industrial Park, and TaiChung Harbor. Preliminary studies on the causes are also included to serve for future references for the development of reclaimed lands.

英文篇名

INVESTIGATION ON SOIL LIQUEFACTIONS DURING THE CHI-CHI EARTHQUAKE

作者

黃俊鴻、楊志文、譚志豪、陳正興

關鍵字

集集地震、土壤液化、地盤流動

摘要

本文整理分析集集地震之地動資料、土壤液化調查及鑽探試驗資料，提出初步研究結果，內容包括：(1)地動強度與延時特性；(2)液化地點與土壤特性；(3)土壤液化現象與結構物損害調查；(4)臨界液化強度曲線之檢核。結果顯示此次地震液化之土壤具有較高之細料含量，有很多側向流動之案例破壞，所獲資料可用於檢核土壤液化評估準則。

英文摘要

This paper presents the results of reconnaissance and preliminary analyses about soil liquefactions occurred during the Chi-Chi earthquake. This study focused on: (1)ground motion characteristics; (2)soil characteristics of liquefied sites; (3)liquefied phenomena and structure damages; (4)verification for critical cyclic strength curve of soil liquefaction. Results show that the liquefied soils have rather high fines content and lateral spreadings are very common in this earthquake. Data obtained can be used to verify the cyclic strength curve commonly used in engineering practices.

英文篇名

INVESTIGATIONS ON THE DAMAGED NORTH WHARF OF TAICHUNG HARBOR AFTER THE 921, CHI-CHI EARTHQUAKE

作者

蘇吉立、李延恭

關鍵字

集集地震、台中港

摘要

本文主要在調查及分析921地震後台中港北碼頭之災象，作為工程設計及維修之參考。根據調查及分析結果，台中港北碼頭主要災象有：噴砂堆、噴砂孔、龜裂、破裂、沉陷、拱起、傾斜、崩塌等。導致上述災象主要原因為地震力、土壤液化與滲漏所造成。

英文摘要

A severe disaster due to 921 earthquake occurred in the north wharf of Taichung harbor. The damages of wharf has been investigated and studied. This paper provide the detailed investigations which will be useful for the maintenance or construction for harbor engineering. After site investigation, it is found that the damages occurred in the north wharf include sand boiling, rupture, ground settlement, heaving and tilting of structures. The main reasons which caused the damages are the large intensity of shaking, soil liquefaction and leakage of sandfills behind the caissons.

英文篇名

CHI-CHI EARTHQUAKE INDUCED FOUNDATION FAILURES AND THE REMEDIAL MEASURES

作者

廖洪鈞、陳堯中

關鍵字

集集大地震、基礎震災、土壤液化、復建對策

摘要

本文主要是針對921集集大地震之基礎震災調查結果加以探討，並就部分基礎破壞形式，提出重建對策。基本上，集集大地震對結構物之破壞，主要是集中在上部結構。對下部基礎的損害，並不嚴重。經對主要震災區之19個鄉鎮的457件基礎破壞案例調查後，發現計有267件（58%）屬基礎與上部結構之界面（如柱腳）破壞，123件（27%）屬斷層引致之基礎隆起破壞，67件（15%）屬土壤液化引致之基礎破壞。離震央較遠，但有斷層經過的地區，基礎破壞案例都集中在斷層附近。但隨著與震央距離之靠近，則除了斷層因素外，地震力對基礎的破壞案例也愈多。至於土壤液化對基礎所造成的破壞，因地區集中，規模不大，並未造成大規模的基礎破壞。此外，文中也就可能會發生液化或已經發生液化地區之建築物基礎補強和修復工作，建議以灌漿固化土壤的方式或是基礎托底之方式來進行，惟選用灌漿材料時需注意其在土壤中之耐久性，托底用之基樁要能承受土壤液化時之動態側向力。

英文摘要

This paper is aimed to evaluate the investigation results of the Chi-Chi earthquake induced foundation failures and to propose some possible remedial measures for the liquefaction resulted foundation failure. Basically, most of the earthquake induced damages were on the upper structures. The damages to the foundation were minor. Totally, 19 towns and cities were investigated and 457 foundation failure cases were reported. Among them, 267 cases (58%) were related to the interface failure between upper structure and foundation; 123 cases (27%) were subjected to the fault induced surface up-heave; and 67 cases (15%) were caused by the subsoil liquefaction. For areas far from the epicenter but with the fault passing through, the foundation failures were mainly caused by the surface up-heave and were concentrated along the fault. For area closer to the epicenter, not only the fault induced surface up-heave but also the earthquake force are the major causes of foundation failure. As a result, the distribution of the foundation failure spread wider. Since the soil liquefaction was only occurred in certain areas and the scale was small, the liquefaction induced foundation failure was not significant. To improve the ground condition against liquefaction for the areas had been attacked or will possibly be attacked by the liquefaction, both the grouting method and the underpinning method are recommended here considering their workability and effectiveness. But the long term durability of grouting material and the resistance against the lateral load of underpinning piles should be carefully evaluated.

英文篇名

FAILURE OF EARTH RETAINING STRUCTURES UNDER CHI-CHI EARTHQUAKE

作者

方永壽、陳滄江、楊育智、湯程傑

關鍵字

地震、破壞、擋土牆

摘要

本研究依據集集大地震所造成砌石擋土牆、重力式擋土牆及加勁擋土牆之破壞案例，進行探討並獲得以下結論。公路邊坡擋土結構物可能因地震力作用造成滑移式及傾覆式破壞。除了動態土壓力外，擋土牆上邊坡受地震力作用向坡腳方向的側向擴張，也可能對擋土牆的滑移與傾覆造成重大影響。斷層錯動的威力強大，建造於斷層上的擋土牆可能因斷層的垂直及水平位移而產生嚴重的傾覆與滑移，應避免於活動斷層上建造任何擋土結構物。

英文摘要

This paper reports failure of gravity walls, masonry walls and reinforced-earth walls related to the 1999 Chi-Chi earthquake. After the earthquake, sliding and overturning failure of retaining structures were observed. The failures were most probably induced by the dynamic earth-pressure and lateral spreading of the uphill slope. A gravity wall built right above the Chelungpu fault was severely damaged by the vertical and horizontal movements of the fault. It is suggested not to build any retaining structure on top of an active fault.

英文篇名

THE PREMIER INVESTIGATION ON LANDSLIDE AND LANDSLIDE DAM AFTER CHI-CHI EARTHQUAKE

作者

蔡光榮、王弘祐、林金炳、侯峻棕、林昆賢

關鍵字

集集地震、地震工程、山崩、堰塞湖

摘要

1999年9月21日凌晨1時47分於台灣中部地區南投縣日月潭西偏南12.5公里處發生芮氏地震規模達7.3之強烈地震，誘發大茅埔~雙冬斷層產生錯移，進而觸動車籠埔斷層發生劇烈錯動位移，致使此二南北走向斷層所經之處樓倒村毀、天崩地裂與人亡財失，造成極為嚴重災害，而斷層帶沿線之各項公共工程設施、高樓民宅、維生管線、道路橋樑、水利設施、農糧設備、古蹟建築、交通建設、水庫埧工、水土保持工程等相關政府與民間工程均因受此二斷層錯動而產生巨大地表垂直與水平位移，而深受重創，已非短期內即可復原。國內外專家學者為配合政府救災行動和災後重建工作之推動，並積極防患二次災害之發生和其可能衍生災區範圍之擴大而加重災情。故本文乃對集水區治理、崩塌地處理與災害治理等各項相關治山防災工作，先行以災後航照地形和衛星影像作初步研判，並建立災區之基本GIS圖層，再以GPS作實地現況初步調查，俾期取得災情背景資料，予以彙整分析，提供後續災後重建工作推動之參考。

英文摘要

The Chi-Chi earthquake occcurred at September 21 early morning (1:47AM) in 1999. The epienter was located at 12.5 Km far from the west of Sun-Moon Lake, Chi-Chi, Nantou county . It has been recognized as a serious disaster caused by Chi-Chi earthquake. The Damges of public consturction, agricultural facilities, humman activities supporting networks and transportation systems have been identfied and investigated by using aerophotography and satellite image processing technology. 2365 landslide spots have been identified by the aerophotography technology. The stability of dam-forming landslide located at Nantou county proved to be critical and important in the disaster area. The volume of impoundment was estimated to be 35*106m3 in total area of 698 ha. .In fact, the most common initiation mechanisms for dam-forming landslide are excessive rainfall, snow melt and earthquake. However, most landslide dams are remarkably short lived. The landslide daming of rivers in Nantou county has proved to be a significant hazard in the near future . The main purpose of this premier investigations is to collect all informations which can give a reference for the stabliization of landslide and landslide dam afer Chi-Chi earthquake.

英文篇名

PRELIMINARY GEOTECHNICAL EXAMINATION OF DAMS AND TUNNELS IN CHI-CHI EARTHQUAKE

作者

張吉佐、張森源

關鍵字

集集大地震、壩工、隧道

摘要

集集大地震是台灣百年來震央位於陸上之最大地震。在震央距離50km範圍內，有若干大型壩工及隧道受到極大的搖動。經檢視這些結構物的震後情形發現，除石岡壩受地表斷裂帶穿過造成較大之破壞外，其餘壩工並無明顯之損害。隧道部份，較嚴重之損害則僅發生於因地表錯動而斷裂的石岡壩引水隧道。整體而言，我國壩工技術已在本次地震通過嚴格的考驗，而隧道的耐震性能在本次地震亦獲得再次的驗證。

英文摘要

The Chi-Chi earthquake was the most violent one among those earthquakes occurred on land during this century. Many large dams and tunnels located within 50 km circle of the epicenter were shaked by violent ground tremble. After careful inspection of those structures, no significant damages except Shikang dam whose vertical alignment was abruptly changed by differential ground uplifts. As for tunnels, only the outlet tunnel of Shikang dam collapsed due to ground offset. From overall review, current geotechnique for dams in Taiwan have passed a severe challenge during the earthquake. Incidentally, earthquake resistance characteristics of tunnel has been proven in many tunnels during this earthquake.

英文篇名

A PRELIMINARY REVIEW ON THE SEISMIC SAFETY ASSESSMENT METHOD FOR EARTH DAM BASED ON CHI-CHI

作者

陳錦清、張森源

關鍵字

土石壩、地震安全評估、應變潛能、沉陷變形

摘要

本文利用國內外土石壩受地震侵襲之案例資料及國內主要大壩地震安全評估之結果，檢討國內土石壩之抗震能力及目前採用之地震安全評估方法之可靠性。921集集地震對土石壩影響之案例資料顯示，施工良好之滾壓土石壩可承受0.6g最大加速度之地震尚不致於發生嚴重之損壞。目前國內採用之地震安全評估方法，對壩體動態反應與壩體沉陷亦能獲得合理之估計。

英文摘要

Based on the case histories of earthquake performance of earth dam collected from Taiwan and abroad, a preliminary review on the seismic performance of earth dam in Taiwan and the reliability of the seismic safety assessment methodology adopted was made. The effects of 921 Chi-chi earthquake on earth dams show that well-constructed earth dam can resist strong shaking with as high as 0.6g without severe damage. The methodology of seismic safety assessment adopted can estimate the dynamic response and the final settlement of dambody reasonably well.