未完全受阻地震滑坡运动距离的影响因素及机制分析

引用本文

樊晓一, 李天话, 田述军, 张友谊, 孙新坡. 未完全受阻地震滑坡运动距离的影响因素及机制分析[J]. 地震地质, 2017,39(4): 754-767.
FAN Xiao-yi, LI Tian-hua, TIAN Shu-jun, ZHANG You-yi, SUN Xin-po. CONTROLLING FACTORS AND MECHANISMS OF INCOMPLETE OBSTRUCTION SEISMIC LANDSLIDE MOBILITY[J]. SEISMOLOGY AND GEOLOGY, 2017,39(4): 754-767. 复制到剪切板

Doi:10.3969/j.issn.0253-4967.2017.04.010
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未完全受阻地震滑坡运动距离的影响因素及机制分析

樊晓一, 李天话, 田述军, 张友谊, 孙新坡

西南科技大学土木工程与建筑学院, 绵阳 621010

〔作者简介〕樊晓一, 男, 1974 年生, 2007年于中国科学院成都山地灾害与环境研究所获理学博士学位, 教授, 主要从事岩土工程及地质灾害方面的教学与研究工作, E-mail:xyfan1003@126.com。

收稿日期: 2016-06-12

基金项目: 国家自然科学基金 (41272297, 41401195, 41472325)、四川省科技厅项目(2014JY0121)、四川省教育厅重点项目(14ZA0095)与绵阳市科技计划项目(16S-02-4)共同资助

摘要

地形条件、启动机制和岩性条件是滑坡运动的主要影响因素。通过分析汶川地震诱发的215处体积>1×10⁴m³的未完全受阻滑坡的运动场地地形条件、岩性、地震烈度、岩层倾向与坡向的关系, 建立各影响因素的分类指标, 分析各影响因素对滑坡运动距离的影响及作用机制。研究结果表明: 场地地形条件不仅显著地影响了大型滑坡的运动距离, 而对中小型滑坡同样有效, 是同等规模下滑坡运动距离产生差异的最主要影响因素。运动场地地形条件中沟谷顺直型滑坡的运动距离最大, 随后依次为凹面型、阶梯型、沟谷偏转型、坡脚堆积型和坡面堆积型, 由岩性、地震烈度和岩层倾向与坡向关系确定的滑坡成因模式或启动机制对中小型规模的滑坡运动距离影响不显著。对于体积>1×10⁶m³的大型滑坡, 同等规模下中等硬度岩性的运动距离大于坚硬岩体和软岩; 在Ⅸ-Ⅺ度地震烈度区, 与滑坡点密度和面积密度的分布规律相反, 滑坡运动距离随烈度的增加而减小; 坡体结构虽然影响了滑坡发育的分布规律和成因模式, 但对滑坡运动距离的作用却不显著。

关键词: 未完全受阻滑坡; 运动距离; 影响因素; 作用机制

中图分类号:P642.22 文献标志码:A 文章编号:0253-4967(2017)04-0754-14

CONTROLLING FACTORS AND MECHANISMS OF INCOMPLETE OBSTRUCTION SEISMIC LANDSLIDE MOBILITY

FAN Xiao-yi, LI Tian-hua, TIAN Shu-jun, ZHANG You-yi, SUN Xin-po

School of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China

Abstract

The topography, occurrence mechanism and lithology are the important factors of landslide movement. The lithology, seismic intensity, geological structure and topography in the travel path of 215 incomplete obstruction landslides with volumes more than 10⁴m³ induced by Wenchuan earthquake were studied. Based on the classification of the factors established, we studied the factors influencing the movement distance of incomplete obstruction landslides. The following results are drawn. In the influence factors of topography in the travel path, the distance is largest in the straight valley topography, followed by the concave, ladder, turning valley, slope toe-type and slope-type landslides, in turn. The topography not only has remarkable influence on the distance of large-scale landslides, but also on the medium and small-scale landslides as well, which is the most important factor influencing the distance. The formation mechanism controlled by lithology, seismic intensity and geological structure has little influence on the mobility of medium- and small-scale landslides. For the large-scale landslides with volume more than 10⁶m³, the distance of landslide with medium hard rock is larger than landslides with hard and soft rock. In the seismic intensity Ⅸ to Ⅺ areas, the landslide distance decreases with intensity increasing, contrary to the distribution of landslide-point density and landslide-area density. The geological structure has influence on the slide aspect of landslides and occurrence mechanism, but the influence is not remarkable to the landslide movement distance.

Keyword: incomplete obstruction seismic landslide; movement distance; influence factor; mechanism

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0 引言

滑坡的运动和堆积具有2种典型特征: 1)完全受阻滑坡, 是指滑坡体的运动方向与沟谷的延伸方向以直角或近似直角相交, 滑坡前缘冲击对面斜坡, 滑坡体的运动被对面斜坡完全阻止, 沿沟谷上、下游两侧堆积, 堵塞河道, 形成堰塞坝, 如汶川地震诱发的唐家山滑坡、大光包滑坡、肖家桥滑坡等。这类滑坡的运动距离完全受阻于对面山体, 未能充分展示其运动性特征。2)未完全受阻滑坡是指滑坡前缘在开阔的地形上运动, 在相对平缓的斜坡或平坦的地面停止堆积, 或者在沟谷地形中滑坡起始运动方向与沟谷下游延伸方向基本一致或斜交, 滑坡运动未受对面斜坡的完全阻止, 滑坡的运动能量和过程得以相对充分地发挥, 产生相对较远的运动距离, 导致严重的人员伤亡、建筑损毁和掩埋, 如王家岩滑坡、东河口滑坡、鼓儿山滑坡等。

滑坡的运动性一直以来都是灾难性滑坡研究的关键问题, 包含了滑坡物源启动、运动、堆积过程。高速远程滑坡的运动机制研究涉及到固、液、气的作用机理, 空气润滑、颗粒流、能量传递、底部超孔隙水压力等理论模型, 以及气垫效应、滑面液化、碎屑流动等作用效应(程谦恭等, 2007; 张明等, 2010; Sosio et al., 2012; Pudasaini et al., 2013; Yang et al., 2014)。但地震滑坡运动的作用和机制与滑坡运动场地地形条件、岩土体特性、地震以及坡体结构等因素密切相关。

地震滑坡的启动机制包括拉裂-走向滑移、拉裂-顺层(倾向)滑移、拉裂-水平滑移和拉裂-散体滑移(许强等, 2009); 滑源区的高位剪切抛掷机制(朱守彪等, 2013)、跳跃-弹射机制(Tang et al., 2015)、逆断层斜冲机制(Dai et al., 2011)等。地震滑坡在强大的加速度惯性力作用下启动, 受其规模和岩性、地形地貌、坡体结构以及前缘沟谷地形走向等因素影响表现出不同的运动性特征。这些启动机制受控于滑坡区所处的地质环境条件、坡体结构以及岩性特征, 并在地震滑坡发育特征的研究上取得了丰富的研究成果, 但是启动机制对滑坡运动性的影响还不明确。

灾难性滑坡常具有高速、远程运动特征, 其运动机理成为滑坡动力学研究的热点, 其运动过程与机制取决于滑坡的总能量, 如果滑坡运动不明显地受下垫面场地条件的阻止, 滑坡的运动参数很大程度上受控于滑坡体积(Legros, 2002)。因此, 本文根据调查、收集和解译的汶川地震诱发的215个体积> 1× 10⁴m³的未完全受阻滑坡数据(表1), 数据来源于许强等(2009)著的《汶川大型滑坡研究》、 google earth pro、 Spot4和航空影像(http://www.scgis.net/scgcmap/map.html#)。以场地地形条件、岩性、地震烈度、岩层倾向与坡向的关系为影响因素, 分析滑坡体积(V)与最大水平运动距离(L)的关系, 探讨这些因素对滑坡运动距离的影响及作用机制。

表1 滑坡数据 Table1 Landslide data

序号	滑坡名称	纬度/(° )	经度/(° )	体积V /dam³	距离 L/m	序号	滑坡名称	纬度/(° )	经度/(° )	体积V /dam³	距离 L/m
1	安子	31.752	104.354	30	160	109	马桑岭2号	31.856	104.452	80	364
2	八扎庙	31.393	104.010	120	260	110	马腰岗	30.986	103.457	10	124
3	白沙沟	31.964	104.569	210	394	111	毛虫山	32.241	104.912	450	933
4	白石子	31.163	103.541	130	265	112	梅子林村	31.499	104.109	60	265
5	白水皂	31.425	104.115	150	510	113	棉角坪	31.842	104.491	3 440	1 054
6	白堰塘1号	31.741	104.248	280	630	114	庙子岭	32.290	105.025	50	187
7	白堰塘2号	31.740	104.243	30	217	115	磨子沟	31.161	103.578	100	411
8	白堰塘3号	31.744	104.239	250	533	116	魔芋评1号	31.888	104.483	50	222
9	白云顶	30.992	103.470	90	423	117	魔芋评2号	31.886	104.482	40	217
10	百花乡	31.001	103.479	180	274	118	魔芋评3号	31.885	104.480	20	183
11	柏树岭	31.809	104.390	1 340	1 100	119	墨家坪	31.758	104.301	240	504
12	板子厂	31.758	104.249	40	173	120	木瓜园	32.299	105.064	60	314
13	冰口石1号	31.346	103.707	4 550	1 560	121	木红坪	32.287	104.983	430	940
14	冰口石2号	31.370	103.700	2 740	1 080	122	牛滚氹沟	31.467	103.917	360	536
15	陈家磨坊	31.475	104.079	160	256	123	偏桥子	31.822	104.370	70	346
16	陈山村	31.802	104.390	930	733	124	平房头	31.733	104.146	70	305
17	窗子沟1号	31.518	104.083	500	490	125	平溪村	32.276	104.941	280	400
18	窗子沟2号	31.516	104.083	130	413	126	坪上	32.288	105.061	270	580
19	大柏兴	31.804	104.350	90	245	127	蒲家沟	32.385	105.059	260	560
20	大崩山沟	31.331	103.657	440	578	128	七郎庙	31.739	104.229	250	605
21	大水井	31.075	103.612	160	338	129	青龙村	32.358	105.036	1 650	770
22	大洼山	32.332	104.999	140	347	130	邱家山1号	32.378	105.046	100	288
23	大窝	31.819	104.309	10	135	131	邱家山2号	32.377	105.054	30	165
24	大屋基	31.701	104.197	3 650	1 540	132	任家山	31.758	104.408	60	258
25	大竹坪	31.617	104.148	2 940	885	133	三叉沟	31.838	104.393	190	480
26	刀砍山	31.807	104.283	10	158	134	沙坝村	31.847	104.487	210	497
27	倒栽桥	31.150	103.431	1 320	890	135	杉树林	31.181	103.508	220	695
28	邓家火地	31.490	104.054	390	550	136	上银杏坪	31.176	103.499	100	266
29	东地坪	32.274	104.933	30	255	137	深溪沟1号	31.103	103.622	10	104
30	东河口	32.408	105.110	16 460	2 400	138	深溪沟2号	31.102	103.624	30	205
31	东溪沟	31.868	104.476	1 830	930	139	深溪沟3号	31.101	103.625	10	128
32	董家	32.343	105.031	290	277	140	深溪沟4号	31.097	103.621	170	443
33	独木桥	31.811	104.338	3 970	1 810	141	深溪沟5号	31.103	103.622	20	148
34	杜家岩	32.333	105.028	510	840	142	石板沟村	32.420	105.091	4 320	1 607
35	断头崖	31.445	103.971	630	638	143	石凑子	32.244	104.912	80	273
36	二道河	31.252	103.610	600	625	144	石岗坪	31.397	104.025	370	567
37	翻山岭	31.662	104.287	110	371	145	石家山	31.990	104.615	2 180	878
38	风岩子	31.754	104.421	620	790	146	石窝头	31.726	104.101	180	527
39	风岩子	31.754	104.421	620	790	147	水磨沟	31.452	103.979	8 320	2 050
40	福烟沟	31.421	103.501	400	760	148	四坪	31.410	103.948	200	517
41	付家山1号	31.581	104.121	200	475	149	苏家院	32.280	104.945	80	180
42	付家山2号	31.582	104.125	20	130	150	孙家院子1号	30.881	103.321	50	186
43	付家山3号	31.583	104.126	80	217	151	孙家院子2号	30.880	103.321	60	255
44	甘溪铺	31.077	103.503	40	235	152	塔子坪	31.108	103.629	590	656
45	公棚1号	31.167	103.478	920	601	153	太子庙	31.855	104.597	5 630	2 227
46	公棚2号	31.184	103.466	50	275	154	糖坊	31.875	104.486	30	197
47	古埋沟	32.269	104.965	1 010	907	155	田梁上	31.943	104.567	80	300
48	古溪沟村1号	31.000	103.465	170	263	156	桐子湾	31.434	104.119	200	573
49	古溪沟村2号	30.999	103.465	80	275	157	头梁子	31.095	103.518	30	285
50	鼓儿山1号	31.918	104.575	480	440	158	土门乡1号	31.723	104.094	170	348
51	鼓儿山2号	31.919	104.577	2 350	900	159	土门乡2号	31.704	104.092	360	503
52	鼓儿山3号	31.921	104.577	1 190	650	160	土门乡3号	31.724	104.090	180	642
53	观音堂	31.793	104.380	20	172	161	瓦前山	32.375	105.050	290	480
54	海心沟	31.527	103.941	4 800	1 363	162	王大包	32.389	105.085	250	680
55	蒿地坪	32.330	104.990	450	485	163	王家坪1号	31.537	104.073	80	317
56	红麻公	32.301	104.961	900	835	164	王家坪2号	31.529	104.062	200	375
57	红石沟	31.616	104.122	8 670	2 837	165	王家岩	31.826	104.449	890	680
58	黄坝狮	31.212	103.538	490	495	166	围子坪	32.386	105.093	950	770
59	黄泥杠1号	31.045	103.450	50	260	167	文家沟	31.553	104.154	41 000	4 250
60	黄泥杠2号	31.046	103.450	80	402	168	窝氹	31.096	103.477	40	190
61	黄水河	31.498	104.060	340	535	169	窝前	32.306	104.964	6 640	1 950
62	黄秧坪	31.526	104.080	30	170	170	窝子沟	32.239	104.874	90	526
63	鸡棚子2号	30.816	103.248	120	350	171	屋基包	32.296	104.956	90	295
64	集中村	30.982	103.454	40	168	172	无音寺	31.091	103.520	20	235
65	椒子园	31.812	104.400	110	364	173	武显庙	31.796	104.376	70	229
66	金河磷矿	31.440	104.018	820	753	174	峡马口	31.370	103.969	380	633
67	金牛驼沟	31.441	103.876	1 250	1 265	175	峡马口村	31.362	103.985	50	324
68	九道拐1号	31.742	104.271	2 220	1 307	176	下石槽	31.664	104.297	320	640
69	九道拐2号	31.717	104.126	660	600	177	夏家坪	31.122	103.655	620	683
70	九龙沟	30.852	103.439	30	247	178	夏家湾	31.823	104.399	110	433
71	烂泥沟1号	31.504	104.084	330	574	179	香樟树	31.804	104.398	10	140
72	烂泥沟2号	31.505	104.081	30	267	180	向家梁子	31.715	104.136	19 540	2 777
73	老虎嘴	31.090	103.486	800	465	181	肖家湾	31.673	104.343	630	530
74	老虎嘴沟1号	31.096	103.518	630	770	182	小湾1号	31.063	103.525	30	187
75	老虎嘴沟2号	31.085	103.508	400	650	183	小湾2号	31.072	103.526	20	220
76	老木沟1号	31.850	104.374	360	617	184	小溪湾	32.381	105.073	220	567
77	老木沟2号	31.848	104.375	90	335	185	谢家店子	31.304	103.837	3 940	1 690
78	老木沟3号	31.849	104.375	80	296	186	谢家山	31.711	104.240	760	1 022
79	老窑子	31.210	103.548	360	575	187	新店子	31.755	104.262	590	706
80	擂鼓1号	31.756	104.429	90	188	188	旋转沟	31.854	104.449	110	313
81	擂鼓2号	31.753	104.431	90	235	189	岩碉窝	32.393	105.098	470	783
82	梨儿包	31.748	104.271	120	370	190	岩上	31.834	104.385	110	366
83	两河口	31.178	103.551	280	600	191	燕岩村	31.089	103.621	40	218
84	廖道坪	31.512	104.182	240	335	192	羊儿坪	31.568	104.209	60	180
85	林家山	32.270	104.932	1 000	701	193	羊角桥	31.131	103.575	730	565
86	岭头	32.362	105.053	530	465	194	杨家沟	31.675	104.310	660	660
87	刘家磨子	31.023	103.398	270	540	195	杨家山1号	31.530	104.083	90	335
88	刘家坪1号	31.764	104.380	70	248	196	杨家山2号	31.496	104.098	50	278
89	刘家坪2号	31.765	104.377	120	256	197	杨家岩1号	31.755	104.329	170	505
90	柳树坪	32.365	105.053	270	652	198	杨家岩2号	31.754	104.328	30	215
91	龙神堂1号	31.721	104.252	230	600	199	杨家岩3号	31.753	104.328	40	255
92	龙神堂2号	31.725	104.251	160	404	200	杨芋店	31.730	104.120	160	395
93	龙湾村	31.922	104.569	820	805	201	银杏1号	31.140	103.466	3 270	1 240
94	龙眼洞	31.753	104.258	10	195	202	银杏2号	31.142	103.465	1 050	806
95	罗池	31.587	104.129	80	322	203	银杏3号	31.148	103.470	900	687
96	罗家磨子	31.111	103.622	170	340	204	映秀镇	31.059	103.494	130	340
97	罗圈湾沟	31.204	103.536	90	315	205	油碾村	30.990	103.467	130	365
98	罗子寺	31.321	103.842	810	877	206	玉皇庙	31.741	104.172	30	265
99	罗子寺	31.330	103.845	740	573	207	皂角湾沟	31.143	103.536	170	410
100	骆家山1号	31.243	103.856	110	295	208	张家沟	31.890	104.529	330	580
101	骆家山2号	31.246	103.855	30	280	209	张家坪	31.836	104.376	110	327
102	麻地坪	32.357	104.995	560	760	210	张家山	31.572	104.192	3 020	1 296
103	麻柳坝	32.286	104.946	20	124	211	张正坡	32.329	105.017	630	817
104	马槽滩	31.424	104.004	380	640	212	长河坝	31.194	103.544	1 070	675
105	马家河坝1号	31.102	103.475	30	207	213	赵家山	32.340	105.044	510	653
106	马家河坝2号	31.103	103.475	20	145	214	中杠梁子	31.203	103.801	80	310
107	马家河坝3号	31.104	103.474	20	176	215	走马坪	31.142	103.511	1 150	807
108	马桑岭1号	31.855	104.450	530	792

表1 滑坡数据 Table1 Landslide data

1 场地条件

由于本文所分析的滑坡运动不受河流或沟谷地形的完全阻止作用, 滑坡的运动场地类型包括开阔型和沟谷型场地地形。开阔型场地地形表明在滑坡运动方向的横断面上地形平坦、开阔。滑坡的运动受侧面边界地形的影响较小。滑坡在启动、运动和堆积区的地形上分布3个不同的原始平均地形坡度: 滑源区坡度(α )、运动区坡度(β )和堆积区的坡度(γ )。根据3个地形坡度的变化, 将开阔型滑坡划分为4种类型: 坡脚堆积型(樊晓一等, 2015)、坡面堆积型、凹面型和阶梯型(图1Ⅰ -Ⅳ ); 根据滑坡初始运动方向与沟谷下游延伸方向的夹角关系(θ ), 沟谷型滑坡地形条件分为沟谷顺直型和偏转型2类(图1Ⅴ -Ⅵ )。滑坡场地分类及地形条件如表2。

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	图1 未完全受阻滑坡场地地形分类概图Fig. 1 Topographic sketches of incomplete obstruction landslide.

表2 未完全受阻滑坡场地地形条件分类表 Table 2 Topographic type of incomplete obstruction landslide

如果滑坡在运动方向上未明显受阻, 滑坡的体积与运动距离具有较为显著的幂率关系(黄润秋等, 2008)。图2和表3显示了不同类型地形条件的滑坡体积与运动距离之间的显著相关性, 但对于不同类型的地形条件, 同等体积的运动距离存在较大的差异。其中, 沟谷顺直型滑坡的运动距离最大, 随后依次为凹面型、阶梯型、沟谷偏转型、坡脚型和坡面型。滑坡规模级别划分标准与不同规模场地条件的滑坡运动距离统计分析列入表4, 其中, 极差表示同一规模下不同场地条件的最大值与最小值之差, 反映了影响因素的作用大小(樊晓一等, 2010)。地形条件对滑坡运动距离的影响表现为: 对于中小规模的滑坡, 不同类型的地形条件对滑坡的运动距离就产生了较大的影响; 而随着滑坡体积的增大, 影响更加显著。

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	图2 滑坡运动距离与场地地形条件的关系Fig. 2 Relation between movement distance of landslide and topographic type.

表3 地形条件的滑坡体积与运动距离的拟合方程 Table3 Equations of the best power-law fits of data from Fig. 2

表4 滑坡规模与场地条件的运动距离分析表 Table4 Movement distance of landslide volume and topographic type

地震滑坡运动典型的动力类型分为破坏、抛射和流动。统计分析表明体积、地形、巨大的动能和滑坡前缘的高位破裂面是控制滑坡碎屑流运动性的主要因素(Zhang et al., 2013); 沟谷地形和未受阻止扩展地形对滑坡碎屑流的能量耗散相对较低(Nicoletti et al., 1991); 虽然大多数远程滑坡碎屑流具有高位能和陡倾角的滑源区, 导致碎裂滑体在运动路径上加速运动, 但沟谷内分布的大量饱和、松散的全新世沉积物可能是滑坡远程运动最重要的因素(Qi et al., 2011), 导致沟谷地形比开阔地形具有更大的运动性。此外, 滑坡的水平运动距离不但依赖于滑坡的体积, 还受控于运动路径上的地形坡度大小而产生的垂直落差(Daudon et al., 2015), 由于运动区和堆积区地形坡度以及运动方向的显著变化, 滑坡前缘与地面的碰撞将耗散部分运动能量, 因此, 坡度和运动方向明显变化的碰撞地形使滑坡速度在垂直和水平方向上产生巨大的变化(Fan et al., 2016), 显著地影响了滑坡的运动性。

2 地层岩性

滑坡分布区内出露地层丰富, 从前震旦系到第四系均有出露, 且分布复杂。根据岩性特征, 许冲等(2009)将汶川地震发育的滑坡岩性划分为7类, 其中以灰岩、页岩为主的岩组, 以砂岩、粉砂岩、千枚岩、灰岩为主的岩组和以闪长岩, 花岗岩等为主的岩组3类岩组发育的滑坡数量占总数的93.55%, 其他4类岩组发育的滑坡数量很少。根据岩石的软硬程度(陈晓利等, 2011; Guo et al., 2013; 郭沉稳等, 2016)将岩石划分为, 1)坚硬岩: 花岗岩、闪长岩、玄武岩、辉长岩、片麻岩; 2)较硬岩: 灰岩、白云岩、厚层块状砾岩和砂岩; 3)较软岩: 粉砂岩、泥灰岩等; 4)软岩: 泥岩、页岩、千枚岩等。因此, 根据上述岩性特征将未完全受阻滑坡的地层岩性概化为4类(表5)。

表5 滑坡岩性特征表 Table5 Landslide lithology

对于滑坡发育的敏感性而言, 已有的研究表明: 滑坡面积和数量的分布与岩性具有较强的规律性, 滑坡面积分布百分率和频率随岩石强度的减小而增加, 并且滑坡在软岩中的发生概率远大于其他岩类(黄润秋等, 2008; 许冲等, 2009; 陈晓利等, 2011; Guo et al., 2013)。但对于滑坡的运动距离而言, 根据不同岩性特征的滑坡体积与运动距离的统计分布表明(图3, 表6): 当滑坡体积< 1× 10⁶m³时, 同一体积等级下不同硬度岩性的滑坡运动距离之间的差异较小, 岩性对未完全受阻滑坡运动距离的影响不明显; 而当体积> 1× 10⁶m³时, 虽然已有的研究结果表明其运动性特征与体积具有显著相关性(Zhang et al., 2013), 但第Ⅱ 、 Ⅲ 类岩组在同等体积下的运动距离大于第Ⅰ 、 Ⅳ 类岩组。但第Ⅱ 、 Ⅲ 类岩组之间以及第Ⅰ 、 Ⅳ 类岩组之间的运动距离的差异小。

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	图3 未完全受阻滑坡的运动距离与岩性关系Fig. 3 Relation between movement distance of landslide and lithology.

表6 不同岩性的滑坡体积与运动距离的拟合方程 Table6 Equations of the best power-law fits of data from Fig. 3

涉及岩性特征对滑坡的远程运动的作用机制包括滑面液化、颗粒流和能量传递机制。硬岩在运动过程中发生碰撞、碎裂作用, 产生较大的块体体积, 有利于块体之间的能量传递作用, 但其大块体的棱角突出, 块体运动受地面摩擦作用也相对增加, 并且硬度较高的岩体碎屑产生滑动面液化和颗粒流动的作用相对有限, 导致运动距离减小。软岩滑坡在长距离的运动过程中块体破碎较为完全, 整体的颗粒粒径相对最小, 虽然在上部滑体物质的压力下有利于滑动面颗粒的液化效应, 但较小粒径的滑体物质之间的接触面积增加, 导致颗粒之间的能量耗散增大, 颗粒间的能量传递效应以及颗粒流动作用减小, 滑坡运动距离减小。而对于较硬或较软岩性的滑坡而言, 可产生粒径分布较宽级配组成, 滑坡在运动过程中有利于滑面液化、颗粒流或能量传递机制效应的发挥, 致使滑坡产生相对较远的运动距离。汶川地震诱发的典型远程滑坡: 文家沟滑坡、东河口滑坡、窝前滑坡等的岩性属于第Ⅱ 、 Ⅲ 类岩组。

3 地震烈度对运动距离的影响

根据《汶川8.0级地震烈度分布图》, 研究区烈度分布为Ⅵ -Ⅺ 度, 汶川地震的最大烈度为Ⅺ 度。地震滑坡分布的主要烈度区间为Ⅷ -Ⅺ 度, 并且滑坡分布的密度随烈度的增加而增大(Huang et al., 2009), 其中, Ⅹ 度和Ⅺ 度区的滑坡发育密度基本相同, Ⅸ 度区灾害密度只有前两者的 $\frac{1}{3}$ , 而Ⅷ 度区发育密度只有Ⅺ 度区或Ⅹ 度区的 $\frac{1}{10}$ (黄润秋等, 2009)。滑坡分布点密度和面积密度与主断裂的距离、烈度呈显著正相关(Dai et al., 2011)。

图4、表7分析了不同地震烈度下滑坡的运动距离与体积的关系。由于Ⅷ 度区的滑坡数量较少, 不能完全反映该区域地震烈度对滑坡运动距离的影响。从Ⅸ 到Ⅺ 度区, 当滑坡体积< 10⁶m³时, 地震烈度对运动距离的影响较小; 当滑坡体积> 10⁶m³时, 同等体积的未完全受阻滑坡的运动距离随烈度的增加而减小, 即L_Ⅸ> L_Ⅹ> L_Ⅺ, 这与滑坡点密度和面积密度的分布规律相反。

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	图4 滑坡运动距离与地震烈度关系Fig. 4 Relation between movement distance of landslide and seismic intensity.

表7 地震烈度的滑坡体积与运动距离的拟合方程 Table7 Equations of the best power-law fits of data from Fig. 4

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	图5 岩层倾向与坡向的关系Fig. 5 Sketches of geological structure.

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	图6 滑坡运动距离与坡体结构关系Fig. 6 Relation between movement distance of landslide and geological structure.

表8 坡体结构的滑坡体积与运动距离的拟合方程 Table 8 Equations of the best power-law fits of data from Fig. 6

地震滑坡的发育与断层上下盘、距离发震断裂的距离、震中距、地震震级、峰值加速度、地震烈度等因素具有显著的相关性。由于滑坡区所处的地质环境条件、坡体结构以及岩性特征的影响, 地震诱发的大型滑坡产生拉裂-走向滑移、拉裂-顺层(倾向)滑移、拉裂-水平滑移和拉裂-散体滑移等启动机制; 以及滑源区的高位剪切抛掷机制、滑雪跳跃式弹射、断层斜冲机制等, 但这些机制对滑坡运动性的影响并不明确。地震荷载以及产生的抛掷效应可能有助于增加滑坡远程运动(Zhu et al., 2013; Zhang et al., 2015), 但对中小型滑坡而言, 地震烈度对滑坡的运动距离作用并不显著; 而大型滑坡的运动距离与地震烈度呈负相关关系, 表明其受控于其他因素的影响。

4 岩层倾向与坡向的夹角对运动距离的影响

坡体结构对滑坡的发育特征以及斜坡的稳定性具有重要的影响, 坡体结构特征可由岩层倾向与坡向夹角来确定。因此, 本文根据岩层倾向与坡向夹角关系将坡体结构分为顺向坡、顺-斜向坡、逆-斜向坡、逆向坡(图5)和其他类型。分类的指标为: 1)岩层倾向与坡向夹角< 30° 时为顺向坡体结构(柴波等, 2009); 2)岩层倾向与坡向夹角> ³0° 且< ⁹0° 时为顺-斜向坡体结构; 3)岩层倾向与坡向夹角> 90° 且< ¹50° 时为逆-斜向坡体结构; 4)岩层倾向与坡向夹角> 150° 时为逆坡向坡体结构; 5)由于水平岩层、垂直岩层和岩浆岩类岩层无岩层倾向将其确定为第5类坡体结构。

不同坡体结构对滑坡运动距离的影响见图6、表8。当滑坡体积< 1× 10⁶m³时, 未完全受阻滑坡的运动距离基本不受坡体结构的影响; 当滑坡体积> 1× 10⁶m³时, 顺向坡和逆向坡的运动距离最大且随体积的分布规律基本一致, 顺-斜向和逆-斜向坡体的滑坡运动距离次之且分布规律相同, 水平岩层、垂直岩层和岩浆岩类岩层的滑坡运动距离最小。

一般而言, 顺向坡的坡体结构对滑坡的形成机制最敏感, 岩体的稳定性最差, 逆向坡和岩浆岩类的坡体结构具有较好的稳定性。但对于地震滑坡, 由于地表峰值加速度与坡向关系、发震断裂走向、活动特征与坡体结构的组合特征等都影响着滑坡的发育规律(陈晓利等, 2014)。汶川地震滑坡发育规律的研究表明: 坡向与倾向对汶川地震滑坡区域和体积的影响大于坡度和岩石类型(Guo et al., 2013), 滑坡运动的优势方向为东偏北, 东偏南以及西偏北, 垂直于发震断裂(Chigira et al., 2010; 许冲等, 2011), 东向坡和东南坡的滑坡点密度(LPD)和面积密度(LAD)大于其他方向(Qi et al., 2010)。然而, 对于滑坡的运动距离而言, 滑坡发育和运动的优势方向并不与运动距离的大小呈正相关关系。因此, 岩体结构以及由岩体结构影响的滑坡发育分布规律和成因模式, 对滑坡运动距离的作用不显著。

5 结论

本文通过对岩性、地震烈度、岩层倾向与坡向的关系和运动场地地形条件4个因素的研究, 分析了未完全受阻地震滑坡运动距离的影响及其作用机制, 得出如下结论:

岩性、地震烈度和岩层倾向与坡向的关系基本确定了滑坡区所处的地质环境条件、坡体结构以及岩性组合特征, 这些特征导致的滑坡成因模式或启动机制对中小型规模的滑坡运动距离影响较小, 而大型滑坡运动距离的差异是规模效应和场地地形条件作用的结果。

对于体积> 1× 10⁶m³的大型滑坡, 同等规模下较硬和较软岩性的运动距离大于坚硬岩体和软岩。其作用机制在于岩性的软硬程度所产生的滑体岩块或颗粒特性对滑坡运动距离的影响; 从Ⅸ 到Ⅺ 度区, 滑坡分布的密度随烈度的增加而增大, 而同等体积大型滑坡的运动距离随烈度的增加而减小, 这与滑坡点密度和面积密度的分布规律相反; 滑坡发育和运动的优势方向并不与运动距离的大小呈正相关, 岩体结构虽然影响了滑坡发育的分布规律和成因模式, 但对滑坡运动距离的作用却不显著。

运动场地地形条件不仅显著地影响了大型滑坡的运动距离, 而对中小型滑坡同样有效, 是滑坡运动距离最主要的影响因素。其中, 沟谷型滑坡的运动距离最大, 随后依次为凹面型、阶梯型、沟谷偏转型、坡脚堆积型和坡面堆积型。

The authors have declared that no competing interests exist.

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[7]	郭沉稳, 姚令侃, 段书苏, 等. 2016. 汶川、芦山、尼泊尔地震触发崩塌滑坡分布规律[J]. 西南交通大学学报, 51(1): 71-77. doi: 103969/j.issn.0258-2724.2016.01.011. GUO Chen-wen, YAO Ling-kan, DUAN Shu-su, et al. 2016. Distribution regularities of land slides induced by Wenchuan earthquake, Lushan earthquake and Nepal earthquake[J]. Journal of Southwest Jiaotong University, 51(1): 71-77(in Chinese). [本文引用:1]
[8]	黄润秋, 李为乐. 2008 b. “5·12”汶川大地震触发地质灾害的发育分布规律研究[J]. 岩石力学与工程学报, 27(12): 2585-2592. doi: 103321/j. issn: 1000-6915. 2008. 12. 028. HUANG Run-qiu, LI Wei-le. 2008b. Research on development and distribution rules of geohazards induced by Wenchuan earthquake on 12th May, 2008[J]. Chinese Journal of Rock Mechanics and Engineering, 27(12): 2585-2592(in Chinese). [本文引用:2]
[9]	黄润秋, 李为乐. 2009. 汶川大地震触发地质灾害的断层效应分析[J]. 工程地质学报, 17(1): 19-28. HUANG Run-qiu, LI Wei-le. 2009. Fault effect analysis of geo-hazard triggered by Wenchaun earthquake[J]. Journal of Engineering Geology, 17(1): 19-28(in Chinese). [本文引用:1]
[10]	黄润秋, 许强. 2008a. 中国典型灾难性滑坡 [M]. 北京: 科学出版社. HUANG Run-qiu, XU Qiang. 2008a. Catastrophic Land slides in China [M]. Science Press, Beijing(in Chinese). [本文引用:1]
[11]	许冲, 戴福初, 肖建章. 2011. “5·12”汶川地震诱发滑坡特征参数统计分析[J]. 自然灾害学报, 20(4): 147-153. doi: 1013577/j. jnd. 2011. 0424. XU Chong, DAI Fu-chu, XIAO Jian-zhang. 2011. Statistical analysis of characteristic parameters of land slides triggered by May 12, 2008 Wenchuan earthquake[J]. Journal of Natural Disasters, 20(4): 147-153(in Chinese). [本文引用:1]
[12]	许冲, 戴福初, 姚鑫, 等. 2009. GIS支持下基于层次分析法的汶川地震区滑坡易发性评价[J]. 岩石力学与工程学报, 28(S2): 3978-3985. XU Chong, DAI Fu-chu, YAO Xin, et al. 2009. GIS-based land slide susceptibility assessment using analytical hierarchy process in Wenchuan earthquake region[J]. Chinese Journal of Rock Mechanics and Engineering, 28(S2): 3978-3985(in Chinese). [本文引用:1]
[13]	许强, 裴向军, 黄润秋. 2009. 汶川地震大型滑坡研究 [M]. 北京: 科学出版社. XU Qiang, PEI Xiang-jun, HUANG Run-qiu. 2009. Large-Scale Land slides Induced by the Wenchuan Earthquake [M]. Science Press, Beijing(in Chinese). [本文引用:1]
[14]	张明, 殷跃平, 吴树仁, 等. 2010. 高速远程滑坡-碎屑流运动机理研究发展现状与展望[J]. 工程地质学报, 18(6): 805-817. ZHANG Ming, YIN Yue-ping, WU Shu-ren, et al. 2010. Development status and prospects of studies on kinematics of long runout rock avalanches[J]. Journal of Engineering Geology, 18(6): 805-817(in Chinese). [本文引用:1]
[15]	朱守彪, 石耀霖, 陆鸣, 等. 2013. 地震滑坡的动力学机制研究[J]. 中国科学(D辑), 43(7): 1096-1105. ZHU Shou-biao, SHI Yao-lin, LU Ming, et al. 2013. Dynamic mechanisms of earthquake-triggered land slides[J]. Science in China(Ser D), 56(10): 1769-1779. [本文引用:2]
[16]	Chigira M, Wu X Y, Inokuchi T, et al. 2010. Land slides induced by the 2008 Wenchuan earthquake, Sichuan, China[J]. Geomorphology, 118(3-4): 225-238. [本文引用:1]
[17]	Dai F C, Tu X B, Xu C, et al. 2011a. Rock avalanches triggered by oblique-thrusting during the 12 May 2008 M_S8. 0 Wenchuan earthquake, China[J]. Geomorphology, 132(3-4): 300-318. [本文引用:2]
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2009

0.0

柴波, 殷坤龙. 2009. 顺向坡岩层倾向与坡向夹角对斜坡稳定性的影响[J]. 岩石力学与工程学报, 28(3): 628-634.

CHAI

, YIN

Kun-long.

2009. Influence of intersection angle between trend of slope and strata on stability of bedding slope[J]. Chinese Journal of Rock Mechanics and Engineering, 28(3): 628-634(in Chinese).

Bedding slope is the most unstable and most easily deform and fail for all kinds of rock slopes. The upper limit of intersection angle between trend of slope and strata is closely related to rock hardness of bedding slope. In order to analyze the influence of intersection angle between trend of slope and strata on the stability of bedding slope，stability calculating model of bedding landslide is built. Considering the lateral resistance of bedding landslide，according to rock bridge transfixion theory of shear test，the T2b2 and T2b3 rocks are selected as the representatives of soft and hard rocks respectively to analyze the sensitive degree of influence of different intersection angles between trend of slope and strata of bedding slope on slope stability. Finally，the upper limit of angle between the trend of slope and strata for bedding landslide is determined. It is indicated that the slope stability of hard rock is more sensitive than that of soft rock when the intersection angle between the trend of slope and strata changes. It is reasonable that upper limit of the angle for a bedding landslide is 30°. The conclusion is verified by landslides between head of reservoir to Badong in the Three Gorgers Reservoir. The analytical results are very important to analyze the stability of bedding slope and to divide slope structures in potential landslide mapping.

顺向坡是岩质斜坡中稳定性最差、最易变形破坏的斜坡类型，顺向坡岩层倾向和坡向夹角的上限与岩质密切相关。为了分析不同岩质顺向坡岩层倾向与坡向夹角对斜坡稳定性的影响，建立考虑侧限顺层平面型斜坡的稳定性计算模型。考虑斜坡侧向边界阻滑效应，结合直剪试验岩桥贯通理论计算侧向阻力，以T2b2和T2b3分别作为软、硬岩代表，分析不同岩质顺向坡岩层倾向和坡向夹角变化对斜坡稳定性影响的敏感程度，最终给出顺向坡岩层倾向和坡向的上限夹角。结果表明：在考虑侧限时，硬质岩岩层倾向与坡向夹角变化对斜坡稳定性影响的敏感程度高于软质岩，取30°为顺向坡岩层倾向与坡向夹角的上限较合适。通过三峡库区库首至巴东段滑坡统计，验证分析结果的合理性。结论为经验判断顺向坡危险性提供了依据，也可作为区域滑坡危险性评价等工作中坡体结构划分的参考。

... 时为顺向坡体结构(柴波等, 2009) ...

2011

0.0

陈晓利, 邓俭良, 冉洪流. 2011. 汶川地震滑坡崩塌的空间分布特征[J]. 地震地质, 33(1): 191-202. doi: 103969/j.issn.0253-4967.2011.01.018.

CHEN

Xiao-li

, DENG

Jian-liang

, RAN

Hong-liu.

2011. Analysis of land slides triggered by Wenchuan earthquake[J]. Seismology and Geology, 33(1): 191-202(in Chinese).

On May 12,2008,a huge earthquake( M S =8.0)named Wenchuan earthquake hit Sichuan Province in Southwest China and triggered thousands of landslides.Post-seismic investigation and analysis discovered some characteristics of the landslides' spatial distribution.Landslides occurred unevenly on both sides of Longmenshan Fault zone,which are reverse faults and responsible for the Wenchuan earthquake.The majority of the landslides are distributed on the hanging wall of Longmenshan central fault,while only 12%of the total occurring on the footwall.The higher density of landslide is located at both ends of the Longmenshan Faults as well as the middle section.Statistical studies also show the occurrence of landslides has close relationship with ground motion,slope gradient and rock properties and so on.The geological background and evolution history of Wenchuan earthquake region have controlled the local geological and topographical setting and affected the landslide distribution when the great earthquake took place.Due to the exceptionally high topographic gradient and geological features such as loose soil and fragile rocks,this region is notoriously prone to landslide.

汶川地震发生在青藏高原东部边界的龙门山断裂带。该区域由一系列叠瓦状冲断带构成,在大地构造上是连接青藏高原与扬子地台的过渡地带。此次地震引发了大规模的滑坡、崩塌、碎屑流等地质灾害,造成严重的人员伤亡和社会经济财产损失。震后的调查和研究结果表明,在龙门山断裂带的两侧,滑坡崩塌灾害的分布很不均匀。大多数的滑坡崩塌存在于龙门山中央断裂带上盘,只有12%左右的滑坡、崩塌出现在下盘; 滑坡、崩塌等地质灾害发育的高密度区出现在断裂带的两端和中部地区。相关的统计分析表明,此次地震中,滑坡和崩塌等灾害的发育与地形地貌、地震动、坡体岩石性质等密切相关。在硬岩、较硬岩区域,滑坡、崩塌等灾害也广泛发育,这种特点与炉霍、昭通等地震滑坡中获得的认识有所不同。初步的研究结果表明,汶川地震的区域地质构造背景通过对地形地貌及岩石等地质条件的影响,进而对滑坡、崩塌等地质灾害的空间分布起到了一定的控制作用。

... 根据岩石的软硬程度(陈晓利等, 2011 ...

... 陈晓利等, 2011 ...

2014

0.0

陈晓利, 惠红军, 赵永红. 2014. 断裂性质与滑坡分布的关系: 以汶川地震中的大型滑坡为例[J]. 地震地质, 36(2): 358-367. doi: 103969/j.issn.0253-4967.2014.02.007.

CHEN

Xiao-li

, HUI

Hong-jun

, ZHAO

Yong-hong.

2014. Study on the fault mechanics influences on the land slides distribution: A case study from the Wenchuan earthquake[J]. Seismology and Geology, 36(2): 358-367(in Chinese).

More and more earthquake-triggered landslides show the hanging wall effects on the spatial distribution, however, the effects of seismic fault mechanics on landslides development are not clear at present time. Based on a simplified fault model, the knowledge of seismic waves reflecting between the ground surface and the fault plane is applied to explain the reasons why landslides are asymmetrically distributed on the hanging wall side during earthquakes caused by thrust faults. Moreover, this paper discusses the relationship between fault movement directions and the initial slope aspects based on the data of large landslides which occurred during the Wenchuan earthquake. This study shows that fault dip angle can affect landslides distribution, namely with the increasing of fault dip angle, the width of the region subjected to the landslides on the hanging wall side decreases. Also, the slopes whose aspects are in the similar directions as the initial movement direction of seismic fault are prone to failure. The knowledge obtained in this study will help to improve the accuracy in regional earthquake-triggered landslide susceptibility assessment and promote the research on the large landslides mechanism, major influencing factors as well as the possible landslide scales.

越来越多的地震滑坡相对于地震断层的不对称分布震例让人们意识到断层上盘效应的存在。然而，目前有关断裂运动方式与滑坡空间分布关系的研究还不够充分和深入。在收集大量地震滑坡震例资料并获得其分布规律的基础上，建立了一个简化的断层模型，以地震波在地表与断层面之间反射传播特性为基础，探讨断层倾角改变对地表地震动强度的影响。进而，以汶川地震触发的大型滑坡为例，研究了断层的几何特征和运动方式对诱发滑坡空间分布的影响。结果表明，断层的倾角对滑坡空间分布范围具有控制作用，随着倾角的增加，垂直断层走向的滑坡分布范围逐渐减小；并且，大型滑坡的初始坡面受到断裂运动方向的影响，与断裂运动方向一致的坡面更容易发生滑坡。所获结果不仅有助于提高区域性地震滑坡危险区域的预测精度，而且对认识大型滑坡的滑动机制、主控因素以及可能的滑动规模、滑距等也起到促进作用。通过对滑坡崩塌的认识来辅助提高对地质构造、地震断层等的认识，应是地震诱发滑坡崩塌研究的新的意义所在。

... 但对于地震滑坡, 由于地表峰值加速度与坡向关系、发震断裂走向、活动特征与坡体结构的组合特征等都影响着滑坡的发育规律(陈晓利等, 2014) ...

2007

0.0

程谦恭, 张倬元, 黄润秋. 2007. 高速远程崩滑动力学的研究现状及发展趋势[J]. 山地学报, 25(1): 72-84.

CHENG

Qian-gong

, ZHANG

Zhuo-yuan

, HUANG

Run-qiu.

2007. Study on dynamics of rock avalanches: State of the art report[J]. Journal of Mountain Science, 25(1): 72-84(in Chinese).

高速远程崩滑动力学机理的研究,一直是国内外工程地质与山地灾害领域崩塌、滑坡灾害研究的前沿热点问题.对这一研究领域,最近几十年来所取得的研究成果、研究现状及发展趋势进行了述评.厘定了高速远程崩滑的定义;详细地阐述了国内外众多典型重大高速远程崩滑灾害事件的几何学、运动学特征;概述了迄今为止所提出的高速远程崩滑形成的各种动力学机理;分析与讨论了高速远程崩滑动力学机理研究的发展趋势与动向;提出了今后进一步研究的总体思路、目标与应重点解决的关键问题.

... 高速远程滑坡的运动机制研究涉及到固、液、气的作用机理, 空气润滑、颗粒流、能量传递、底部超孔隙水压力等理论模型, 以及气垫效应、滑面液化、碎屑流动等作用效应(程谦恭等, 2007 ...

2010

0.0

樊晓一, 乔建平. 2010. “坡”、 “场”因素对大型滑坡运动特征的影响[J]. 岩石力学与工程学报, 29(11): 2337-2347.

FAN

Xiao-yi

, QIAO

Jian-ping.

2010. Influence of land slide and ground factors on large-scale land slide movement[J]. Chinese Journal of Rock Mechanics and Engineering, 29(11): 2337-2347.

The maximum horizontal distance(Lmax) and apparent coefficient of friction(Hmax/Lmax) are considered as the evaluation criteria of landslide movement. In order to analyze the landslide movement，five influence factors of large-scale seismic and rainfall landslide are considered including landslide volume(V )，landslide height(H )，landslide slope gradient(a )，constraint angle of slope toe(q ) and ground type(X ). The results show that，at the landslide maximum horizontal distance(Lmax)，the landslide height H is the most important factor of rainfall landslides；and it follows by slope gradient(a )，constraint angle of slope toe(q ) and ground type(X ) in turn. When the volume is from 106 to 107 m3，the influence of ground type(X ) on the seismic landslide is larger than rainfall landslide；and the influence factors of seismic landslides are H，X，a，q in sequence. When the volume is larger than 107 m3，the landslide slope gradient a is the most important factor of seismic landslide；and it follows by landslide height(H )，constraint angle of slope toe(q ) and ground type(X ) in turn. By significant analysis，the landslide height(H) is significant influence factor of Lmax of large-scale rainfall landslide and seismic landslide with the volume from 106 to 107 m3. At landslide apparent coefficient of friction(Hmax/Lmax)，the landslide slope gradient(a) is the most important factor of seismic landslides，it follows by landslide height(H)，ground type(X) and constraint angle of slope toe(q) in turn. The influence factors of rainfall landslide with the volume from 106 to107 m3 and larger than 107 m3 are a，H，q，X and H，a，X，q respectively. The H，a，X are significant influence factors of Hmax/Lmax of seismic landslide with the volume larger than 107 m3 by significant analysis.

(1. School of Civil Engineering and Architecture，Southwest University of Science and Technology，Mianyang，Sichuan 621010，China；2. Institute of Mountain Hazard and Environment，Chinese Academy of Sciences，Chengdu，Sichuan 610041，China)

以滑坡的最大水平距离(Lmax)和视摩擦因数(Hmax/Lmax)为评价指标，探讨“坡”(滑坡体积(V )、滑坡高度(H )、滑坡坡度(a ))和“场”(坡脚约束角(θ )、场地条件(X))因素对大型地震滑坡和降雨滑坡运动的影响特征。研究结果表明：在滑坡最大水平距离(Lmax)的影响上，滑坡高度(H)是降雨滑坡的主要因素，影响因素大小的顺序为H，a，θ和X。而对于体积为106～107 m3的地震滑坡，场地条件的影响比降雨滑坡大，其影响因素从大到小的顺序依次为H，X，a和θ。当地震滑坡体积大于107 m3时，滑坡坡度(a )则是Lmax的主要因素，影响因素从大到小的顺序依次为a，H，θ和X。显著性分析结果表明，滑坡高度(H )是大型降雨滑坡和体积为106～107 m3的地震滑坡的最大水平距离Lmax的显著性影响因素。在滑坡的视摩擦因数(Hmax/Lmax)的影响上，滑坡坡度(a)是地震滑坡的主要因素，影响因素从大到小的顺序依次为a，H，X和θ。而对于降雨滑坡，体积为106～107 m3时影响因素从大到小的顺序依次为a，H，θ和X；体积大于107 m3时，则影响因素从大到小的顺序依次为H，a，X和θ。显著性分析结果表明，H，a，X是体积大于107 m3的地震滑坡Hmax/Lmax的显著性影响因素。

... 滑坡规模级别划分标准与不同规模场地条件的滑坡运动距离统计分析列入表4, 其中, 极差表示同一规模下不同场地条件的最大值与最小值之差, 反映了影响因素的作用大小(樊晓一等, 2010) ...

2015

0.0

樊晓一, 冷晓玉, 段晓冬. 2015. 坡脚型与偏转型地震滑坡运动距离及地形因素作用[J]. 岩土力学, 36(5): 1380-1388. doi: 1016285/j. rsm. 2015. 05. 021.

FAN

Xiao-yi

, LENG

Xiao-yu

, DUAN

Xiao-dong.

2015. Influence of topographical factors on movement distances of toe-type and turning-type land slides triggered by earthquake[J]. Rock and Soil Mechanics, 36(5): 1380-1388(in Chinese).

... 根据3个地形坡度的变化, 将开阔型滑坡划分为4种类型: 坡脚堆积型(樊晓一等, 2015)、坡面堆积型、凹面型和阶梯型(图1#cod#x02160 ...

2016

0.0

郭沉稳, 姚令侃, 段书苏, 等. 2016. 汶川、芦山、尼泊尔地震触发崩塌滑坡分布规律[J]. 西南交通大学学报, 51(1): 71-77. doi: 103969/j.issn.0258-2724.2016.01.011.

GUO

Chen-wen

, YAO

Ling-kan

, DUAN

Shu-su

, et al. 2016. Distribution regularities of land slides induced by Wenchuan earthquake, Lushan earthquake and Nepal earthquake[J]. Journal of Southwest Jiaotong University, 51(1): 71-77(in Chinese).

... 郭沉稳等, 2016)将岩石划分为, 1)坚硬岩: 花岗岩、闪长岩、玄武岩、辉长岩、片麻岩 ...

2008

0.0

黄润秋, 李为乐. 2008 b. “5·12”汶川大地震触发地质灾害的发育分布规律研究[J]. 岩石力学与工程学报, 27(12): 2585-2592. doi: 103321/j. issn: 1000-6915. 2008. 12. 028.

HUANG

Run-qiu

, LI

Wei-le.

2008b. Research on development and distribution rules of geohazards induced by Wenchuan earthquake on 12th May, 2008[J]. Chinese Journal of Rock Mechanics and Engineering, 27(12): 2585-2592(in Chinese).

As Wenchuan earthquake was of high magnitude and shallow seismic focus，it caused considerable damage and thousands of geohazards. After a field investigation and the interpretation of remote-sensing images and aerial photographs taken after the earthquake，11 308 earthquake-induced geohazards have been obtained；and the general distribution situation of the geohazards has been learnt. Then，the distribution of these geohazards was investigated statistically using GIS techniques to determine how the occurrence of geohazards correlates with distance from the coseismic fault，slope steepness，elevation and rock type. The main results of this research can be summarized as follows. (1) The geohazards triggered by earthquake show the feature of zonal distribution along the coseismic fault and linear distribution along the rivers. (2) The distribution of earthquake-induced geohazards has marked hangingwall effect，for the geohazard concentration in the hangingwall of coseismic fault is obviously higher than that in the footwall and the width of strong development zone in the hangingwall is about 10 km. (3) the slope steepness is a main factor which controls the development of earthquake-induced geohazards and a vast majority of geohazards are distributed within the range of 20° to 50°. (4) The earthquake-induced geohazards have corresponding relationship with the elevation and micro-landform；for most hazards occur in river valley and canyon section below the elevation of 1 500 to 2 000 m，particularly in the upper segment of canyon section (namely，the turning point from the dale to the canyon). Thin ridge，isolated or full-face space mountains are most sensitive to the seismic wave，and have striking amplification effect. In these areas，collapses and landslides are most likely to occur. (5) The research also shows that different lithologies have no marked corresponding relationship with the development of geohazards，but it determines the types of geohazards. Usually，landslides occur in soft rocks，while collapses occur in hard rocks.

“5.12”汶川大地震具有震级高、震源浅、破坏性强、次生地质灾害严重的特点。通过灾后对地震地质灾害的现场调查和遥感解译，共获得地质灾害点11 308处，对地震地质灾害发育分布有了总体认识。在此基础上，利用GIS技术对地震地质灾害的分布与距发震断裂距离坡度、高程、岩性等因素的关系进行统计分析。研究得出：(1) 地震地质灾害在区域上具有沿发震断裂带呈带状分布和沿河流水系成线状分布的特点；(2) 地震地质灾害分布具有明显的上盘效应，发震断裂上盘地质灾害发育密度明显大于下盘，且上盘强发育带宽度约为10 km；(3) 地形坡度是地震地质灾害发育的控制性因素之一，绝大部分的灾害集中在坡度20°～50°的范围内；(4) 地震地质灾害与高程和微地貌具有很好的对应关系，大部分灾害发生在高程1 500～2 000 m以下的河谷峡谷段，尤其是峡谷段的上部(即宽谷向峡谷的转折部位)，单薄的山脊以及孤立或多面临空的山体对地震波最为敏感，具有显著的放大效应，这些部位崩塌滑坡最为发育；(5) 不同的岩性与地质灾害的发育虽然没有显著的对应关系，但却决定了地质灾害的类型，通常情况下，滑坡多发生在软岩中，而硬岩中多发生的是崩塌。

... 如果滑坡在运动方向上未明显受阻, 滑坡的体积与运动距离具有较为显著的幂率关系(黄润秋等, 2008) ...

... 对于滑坡发育的敏感性而言, 已有的研究表明: 滑坡面积和数量的分布与岩性具有较强的规律性, 滑坡面积分布百分率和频率随岩石强度的减小而增加, 并且滑坡在软岩中的发生概率远大于其他岩类(黄润秋等, 2008 ...

2009

0.0

黄润秋, 李为乐. 2009. 汶川大地震触发地质灾害的断层效应分析[J]. 工程地质学报, 17(1): 19-28.

HUANG

Run-qiu

, LI

Wei-le.

2009. Fault effect analysis of geo-hazard triggered by Wenchaun earthquake[J]. Journal of Engineering Geology, 17(1): 19-28(in Chinese).

A great number of collapse and slide geo-hazards had been triggered by “5·12” Wenchuan Earthquake, covering 0.1M km2 or so. Undoubtedly, their distribution was influenced by topography and morphology, stratigraphy, people's engineering operations, and so on. But their distribution mainly was controlled by the faults triggering seism, and they distributed along those faults like a ribbon. Based on the study in three geo-hazards concentration regions, namely, from Dujiangyan to Wenchuan, from Beichuan to Anxian and from Magong to Hongguang, the following fault effects of geo-hazards in Wenchuan Earthquake were found: (1) Because the triggering-earthquake faults were reverse fault, the distribution of geo-hazards showed clear "Upper plate/lower plate effect". In detail, compared with lower plate, the upper plate had higher distribution density, wider scope and larger scale; (2) Intensely developed region of geo-hazard ranged from 0 to 7 km in upper plate. Moderately developed region ranged from 7 to 11km in upper plate, and from 0 to 5km in lower plate; Vast majority of lager-scale landslides were about 5km away from faults; (3) The transition and stagger parts of fractures are usually the concentration zone of geo-hazards, and large-scale geo-hazards also frequently happened here; (4) The advantage orientation of sliding was NW-SE, which was nearly orthogonal to the extension direction of the fault of Yingxiu-beichuan. This was closed correlation to the fact that the propagation of earthquake wave was perpendicular to the strike of fault; (5) Earthquake geo-hazards mainly developed in these regions where earthquake intensity was equal to or above IX. The density of development was nearly the same in XI intensity zone and X intensity zone. The geo-hazard density in IX intensity zone was only one-third of the two former zones. Whereas, the development density in VIII intensity zone was only one-tenth of XI intensity zone or X intensity zone.

(State Key Laboratory of Geo-Hazard Prevention and Geo-Environment Protection, Chengdu University of Technology| Chengdu |610059)

“5·12”汶川大地震(Ms=8.0)触发了数以万计的崩滑地质灾害，分布范围约10万km2。这些地质灾害的空间分布固然受地形地貌、地层岩性和人类工程活动等因素的影响，然而主要还是受到发震断层的控制，沿发震断裂呈带状分布。通过都(江堰)—汶(川)路、北川—安县、马公—红光3个地质灾害集中发育区的研究，发现汶川地震地质灾害具有以下断层效应：（1）由于属逆断型发震，地质灾害的分布表现出了明显的"上/下盘效应"，发震断层上盘较下盘地质灾害分布密度高、范围广、规模大；（2）断层上盘0~7km范围为地质灾害强发育区，断层上盘7～11km范围和下盘0～5km范围为地质灾害中等发育区；绝大多数的大型滑坡都分布在距断层5km范围内；（3）断裂的转折和错列部位是地质灾害集中发育部位，大型地质灾害也往往发生在这些部位；（4）滑坡滑动的优势方向为NW-SE, 与映秀—北川断裂的空间展布方向基本垂直，这与地震波垂直于断层方向传播有密切的关系；（5）地震地质灾害主要集中发育在Ⅸ度及其以上烈度的区域。其中，Ⅺ度区发育密度与Ⅹ度区的基本相当，Ⅸ度区灾害密度只有前两者的1/3，而Ⅷ度区发育密度只有Ⅺ度区或Ⅹ度区的1/10。

... 度区的 110(黄润秋等, 2009) ...

2008

0.0

2011

0.0

... 许冲等, 2011), 东向坡和东南坡的滑坡点密度(LPD)和面积密度(LAD)大于其他方向(Qi et al ...

2009

0.0

许冲, 戴福初, 姚鑫, 等. 2009. GIS支持下基于层次分析法的汶川地震区滑坡易发性评价[J]. 岩石力学与工程学报, 28(S2): 3978-3985.

Chong

, DAI

Fu-chu

, YAO

Xin

, et al. 2009. GIS-based land slide susceptibility assessment using analytical hierarchy process in Wenchuan earthquake region[J]. Chinese Journal of Rock Mechanics and Engineering, 28(S2): 3978-3985(in Chinese).

2008年5月12日14时28分,四川汶川发生了M_s8.0级大地震,地震诱发了数以万计的滑坡灾害.在大约48 678 km~2的区域内,采用震后遥感影像解译并结合野外调查的方法,共解译出48 007个滑坡.应用GIS技术,建立了汶川地震诱发滑坡灾害及相关地形、地质空间数据库,分析了断层、岩性、高程、坡度、坡向、河流、公路等7个因素与滑坡分布的关系,应用滑坡面积百分比这一标准来分别衡量每个因素中各个级别对滑坡的影响程度;然后使用层次分析法对这7个参数进行权重分析;在GIS平台下对这些参数进行综合分析,通过分析结果将研究区内滑坡按易发程度分为极高易发区、高易发区、中易发区、低易发区与极低易发区5类,极高易发区与高易发区面积约8 211 km~2,占研究区总面积的16.9%;最后,使用汶川地震滑坡数据库对研究结果进行检验,检验曲线表明分区效果良好,其中极高易发区与高易发区内实际发生滑坡面积为430 km~2,占滑坡总面积的60.5%. Abstract： On 12 May 2008,a catastrophic earthquake with surface wave magnitude of 8.0 struck the Sichuan Province of China. Tens of thousand of landslides were triggered by this earthquake over a broad area. 48 007 landslides were interpreted from aerial photographs and multi-source remote sensing imageries,verified by field check. A spatial database,including landslides and associated controlling parameters which may have influence on the occurrence of landslides,was developed and analyzed using geographical information system(GIS) technology. The correlations of landslide distribution with controlling parameters,including faults,lithology,elevation,slope angle,slope aspect,drainages and roads are firstly analyzed,and landslide area-ratio was calculated for each group of the above parameters. An analytical hierarchy process(AHP) was then applied to determine the significance of controlling parameters in triggering the landslides. The resulting susceptibility map showed five classes of landslide susceptibility,i.e. extremely high,high,moderate,low,and extremely low. The area with extremely high and high susceptibility accounts for about 8 211 km~2,16.9% of the study area. This indicates that the result is reasonable in 60.5% of the landslides occurred in high or extremely high susceptibility region.

... 许冲等, 2009 ...

2009

0.0

... 地震滑坡的启动机制包括拉裂-走向滑移、拉裂-顺层(倾向)滑移、拉裂-水平滑移和拉裂-散体滑移(许强等, 2009) ...

2010

0.0

张明, 殷跃平, 吴树仁, 等. 2010. 高速远程滑坡-碎屑流运动机理研究发展现状与展望[J]. 工程地质学报, 18(6): 805-817.

ZHANG

Ming

, YIN

Yue-ping

, WU

Shu-ren

, et al. 2010. Development status and prospects of studies on kinematics of long runout rock avalanches[J]. Journal of Engineering Geology, 18(6): 805-817(in Chinese).

The occurrence of rock avalanche always brings disastrous catastrophes because of its high speed and unexpected long runout. So,its kinematics or moving mechanism has been the focus of engineering geologists around the world since late 19 th century. At present,there are four viewpoints abroad: air-lubrication model,grain flow model,momentum-transfer model and self-undrained loading model. Howver,they have not been widely accepted possibly because of complication. China is a country where frequent rock avalances occur. The research on this field is just at the beginning and most of the research results are qualitative. Based on a review of a plenty of literatures,this paper expounds the development status of study on the transport mechanism of rock avalanches in two aspects of theories and research techniques. It summarizes the existing numerous models,comments on the research difficulties at present. Finally,it puts forward the research directions in the future according to the present bottlenecks. This paper systematically sums up the relevant research status and can be helpful to the future research.

高速远程滑坡-碎屑流具有极高的运动速度和超远距离的位移,往往能够引发灾难性事故,造成严重的生命财产损失,因此,它的运动机理,即高速远程效应机理一直是国内外学者研究的热点。目前国外主要存在四种观点:空气润滑模型、颗粒流模型、能量传递模型和底部超孔隙水压力模型。但是,由于高速远程滑坡-碎屑流自身的复杂性,到目前为止,研究还没有取得公认的成果。中国是高速远程滑坡-碎屑流的频发区,因其研究才刚刚起步,研究成果还处于定性阶段。本文在查阅大量文献的基础上,从理论和技术两方面分别阐述了国内外高速远程滑坡-碎屑流运动机理研究的发展现状,对目前纵多的理论和模型进行了归纳与总结,点评了目前研究的难点,并在此基础上提出了今后的研究重点。本文是国内外首次对该领域的研究进行系统的归纳和总结,对今后类似的研究具较高的参考价值。

... 张明等, 2010 ...

2013

0.0

... 滑源区的高位剪切抛掷机制(朱守彪等, 2013)、跳跃-弹射机制(Tang et al ...

... 地震荷载以及产生的抛掷效应可能有助于增加滑坡远程运动(Zhu et al ...

2010

0.0

... , 2013), 滑坡运动的优势方向为东偏北, 东偏南以及西偏北, 垂直于发震断裂(Chigira et al ...

2011

0.0

... , 2015)、逆断层斜冲机制(Dai et al ...

... 滑坡分布点密度和面积密度与主断裂的距离、烈度呈显著正相关(Dai et al ...

2011

0.0

2015

0.0

... 此外, 滑坡的水平运动距离不但依赖于滑坡的体积, 还受控于运动路径上的地形坡度大小而产生的垂直落差(Daudon et al ...

2016

0.0

... , 2015), 由于运动区和堆积区地形坡度以及运动方向的显著变化, 滑坡前缘与地面的碰撞将耗散部分运动能量, 因此, 坡度和运动方向明显变化的碰撞地形使滑坡速度在垂直和水平方向上产生巨大的变化(Fan et al ...

2013

0.0

... Guo et al ...

... 汶川地震滑坡发育规律的研究表明: 坡向与倾向对汶川地震滑坡区域和体积的影响大于坡度和岩石类型(Guo et al ...

2009

0.0

... 度, 并且滑坡分布的密度随烈度的增加而增大(Huang et al ...

2002

0.0

... 灾难性滑坡常具有高速、远程运动特征, 其运动机理成为滑坡动力学研究的热点, 其运动过程与机制取决于滑坡的总能量, 如果滑坡运动不明显地受下垫面场地条件的阻止, 滑坡的运动参数很大程度上受控于滑坡体积(Legros, 2002) ...

1991

0.0

... 沟谷地形和未受阻止扩展地形对滑坡碎屑流的能量耗散相对较低(Nicoletti et al ...

2013

0.0

... Pudasaini et al ...

2010

0.0

... 许冲等, 2011), 东向坡和东南坡的滑坡点密度(LPD)和面积密度(LAD)大于其他方向(Qi et al ...

2011

0.0

... 虽然大多数远程滑坡碎屑流具有高位能和陡倾角的滑源区, 导致碎裂滑体在运动路径上加速运动, 但沟谷内分布的大量饱和、松散的全新世沉积物可能是滑坡远程运动最重要的因素(Qi et al ...

2012

0.0

... Sosio et al ...

2015

0.0

... 滑源区的高位剪切抛掷机制(朱守彪等, 2013)、跳跃-弹射机制(Tang et al ...

2014

0.0

... Yang et al ...

2013

0.0

... 统计分析表明体积、地形、巨大的动能和滑坡前缘的高位破裂面是控制滑坡碎屑流运动性的主要因素(Zhang et al ...

... 10⁶m³时, 虽然已有的研究结果表明其运动性特征与体积具有显著相关性(Zhang et al ...

2015

0.0

... Zhang et al ...